[top]
000
FXUS66 KHNX 220422
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
922 PM PDT SUN SEP 21 2008
.UPDATE...UPPER LEVEL SHORTWAVE TROF AXIS IS MOVING THRU CENTRAL
CA THIS EVE. HIGH CLOUDS ASSOCIATED WITH THE TROF SHOULD MOVE OUT
SHORTLY SO NO CHANGE TO A CLEAR FCST OVERNITE. TEMPS MON AT OR A
DEGREE OR TWO ABOVE TODAY AS H85 TEMPS BEGIN TO CREEP UP. THE
WARMUP CONTINUES THRU MID WEEK AS AN UPPER RIDGE DEVELOPS OVER THE
DESERT SW.
&&
.PREVIOUS DISCUSSION...THE INFLUENCE OF A COOL AND STABLE AIRMASS
OVER CENTRAL CALIFORNIA CONTINUED TO PROVIDE CLEAR SKIES THIS
AFTERNOON. THE UPPER TROUGH THAT INTRODUCED THE COOLER CONDITIONS
MOVED INTO CANADA TODAY WITH A MORE ZONAL FLOW PATTERN REMAINING
OVER CALIFORNIA. THIS FLOW PATTERN ALLOWED TO LITTLE CHANGE TODAY
WITH TEMPERATURES JUST SLIGHTLY HIGHER THEN THOSE OF YESTERDAY
AFTERNOON. SHORT RANGE MODELS PROG 850MB TEMP TO RISE BY 1-2 DEG-C
ON MONDAY...WHICH SHOULD ALLOW MANY MORE LOCATIONS TO REACH WELL
INTO THE 80S BY AFTERNOON. CONDITIONS WILL REMAIN DRY AS THE FLOW
ALOFT REMAINS IN A GENERALLY ZONAL PATTERN.
BEYOND MONDAY...AN UPPER RIDGE IS STILL EXPECTED TO BUILD IN FROM
THE SOUTHWEST AND INTRODUCE A WARMING TREND BEGINNING EARLY THIS
WEEK. THIS WARMING TREND WILL CONTINUE THROUGH THE END OF THE WEEK
AS THE RIDGE BECOMES THE DOMINATE FEATURE OVER THE WEST. LATEST
MODEL GUIDANCE HAS THE CENTRAL VALLEY WARMING BACK UP INTO THE MID
90S BY MID-WEEK BEFORE ANOTHER COOL DOWN IS INTRODUCED OVER THE
WEEKEND. MODELS SHOW THIS COOL DOWN ASSOCIATED WITH A TROF ENTERING
THE REGION BY THE END OF THE WEEK THAT WILL USHER IN THIS COOL
DOWN OVER THE WEST. THE SYSTEM TOWARD THE END OF THE WEEK WILL
REMAIN DRY WITH NO PRECIP EXPECTED OVER CENTRAL CALIFORNIA.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL
CALIFORNIA INTERIOR THROUGH 06Z TUESDAY.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BINGHAM
AVN/FW...DS
WEATHER.GOV/HANFORD
[top]
000
FXUS66 KLOX 220408
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
910 PM PDT SUN SEP 21 2008
.SHORT TERM (TONIGHT-WED)...LAX ACARS SOUNDINGS THIS EVENING SHOWING
TWO INVERSIONS...ONE AT ABOUT 1800 FT AND ANOTHER AT ABOUT 4800 FT.
DISORGANIZED MARINE LAYER CLOUDS WERE OVER THE SOCAL BIGHT MAINLY S
OF THE CHANNEL ISLANDS AND OFF THE COAST FROM L.A. COUNTY SOUTHWARD.
AN EDDY IS EXPECTED TO DEVELOP OVERNIGHT WHICH SHOULD HELP TO
SOLIDIFY THE MARINE LAYER CLOUD COVER AND PUSH THE CLOUDS INLAND TO
THE VALLEYS AND UP THE COAST TO VTU AND S SBA COUNTY LATER TONIGHT.
LOW CLOUDS WERE SPARSER ALONG AND OFF THE CENTRAL COAST THIS
EVENING. IT LOOKS LIKE LOW CLOUDS SHOULD PERSIST ALONG THE SBA
CENTRAL COAST OVERNIGHT BUT THE EXTENT OF LOW CLOUDS FOR THE SLO
CENTRAL COAST IS QUESTIONABLE. THE WRF IS FORECASTING SOME OFFSHORE
LOW LEVEL FLOW ALONG THE CENTRAL COAST LATE TONIGHT WHICH MAY CAUSE
ANY LOW CLOUDS TO BE PUSHED OFF THE COAST BY SUNRISE...WHICH THE
BOUNDARY LAYER MOISTURE FIELDS ARE SUGGESTING. IT ALSO APPEARS LOW
CLOUDS MAY BE HARD PRESSED TO MOVE INTO THE SALINAS VALLEY LATER
TONIGHT AS WELL. OTHERWISE MOSTLY CLEAR SKIES SHOULD PREVAIL OVER A
GOOD PORTION OF THE FORECAST AREA THROUGH TONIGHT.
A BROAD UPPER TROF OVER CA IS FORECAST TO MOVE E THRU MON...WITH AN
UPPER RIDGE EXPECTED TO BUILD INTO SRN CA FOR TUE THRU WED. A BROAD
WNW FLOW ALOFT CA BE EXPECTED OVER THE DISTRICT THRU MON THEN THE
FLOW WILL TURN MORE WSW FOR TUE AND GENERALLY SOUTHERLY FOR WED. DRY
WEATHER WILL CONTINUE OVER THE DISTRICT THRU WED...WITH GRADUALLY
WARMING TEMPS THRU THE PERIOD. BY WED HI TEMPS SHOULD BE WELL ABOVE
NORMAL IN MANY AREAS AWAY FROM THE IMMEDIATE COAST. THE MARINE LAYER
SHOULD SHRINK SOME AS WELL AND BE AROUND OR JUST BELOW 1000 FT DEEP
BY WED...WITH JUST PATCHY NIGHT AND MORNING LOW CLOUDS AND FOG
EXPECTED FOR THE COASTAL PLAIN BY TUE NIGHT. THE WRF WAS FORECASTING
LITTLE IF ANY LOW CLOUDS FOR THE CENTRAL COAST BY TUE NIGHT AS WELL.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (THU-SUN)...MODELS HAVE BEEN FLIP FLOPPING A BIT FOR THU
AND FRI. A TROUGH SHOULD DIG DOWN FROM ALASKA AND PUSH OUR WARM
RIDGE EASTWARD...BUT WHETHER THAT HAPPENS THU NIGHT LIKE THE 0Z RUNS
SUGGESTED OR FRI NIGHT LIKE THE 12Z RUNS IS LEFT TO BE SEEN. THE 12Z
RUNS ACTUALLY WEAKEN THE ORIGINAL TROUGH...WHILE A RATHER LARGE
TROUGH JUST SOUTH OF ALASKA STEALS SOME OF ITS ENERGY. THIS NEW
SOLUTION RESULTS IN SHIFTING THE HIGH ONLY SLIGHTLY TO THE
EAST...AND KEEPING US FAIRLY WARM FRI THROUGH SUN. NOT ONLY
THAT...BUT THIS PATTERN PUTS THE HIGH INTO A FAVORABLE SOUTHERLY
FLOW REGIME FOR OUR AREA...WHICH COULD PULL UP ANY AVAILABLE
MOISTURE FROM MEXICO. DID NOT BITE ON THIS JUST YET...SINCE THIS
MOISTURE WOULD NOT GET HERE UNTIL FRIDAY...BUT IF THE MODELS
CONTINUE TO SING THE SAME TUNE THROUGH THIS WEEK...IT WILL BE TOUGH
TO IGNORE FOR LONG. EITHER WAY...FRI THROUGH SUN SHOULD BE A BIT
COOLER...BUT UNTIL WERE SEE MORE STABILITY IN THE SOLUTIONS...DID
NOT GET TOO CUTE AND JUST TRENDED TEMPS DOWN A BIT EACH DAY BACK
TOWARD NORMAL.
&&
.AVIATION...22/0406Z...SOME LOW CLOUDS WERE NOTED ON THE CENTRAL
COAST THIS EVENING. LOW CLOUDS SHOULD EVENTUALLY DEVELOP OVER A
WIDER PORTION OF THE CENTRAL COAST TONIGHT AND MOVE INTO KSMX AND
KSBP BY MIDNIGHT OR SHORTLY AFTER. THE WRF WAS FORECASTING LIGHT
OFFSHORE FLOW FOR THIS AREA LATER TONIGHT SO IT IS POSSIBLE ANY LOW
CLOUDS THAT DO MOVE INTO THE AIRFIELDS MAY CLEAR OUT AS EARLY AS 7
AM OR 8 AM. LOW CLOUDS ALSO EXPECTED TO DEVELOP AROUND KPRB LATE
TONIGHT AND EARLY MON.
S OF POINT CONCEPTION...TIMING OF LOW CLOUDS RATHER DIFFICULT...BUT
IT LOOKS LIKE THE LOW CLOUDS SHOULD MOVE INTO KLGB AND KLAX BY 07Z
OR 08Z AS AN EDDY DEVELOPS...THEN SPREAD UP THE COAST AND EVENTUALLY
AFFECT KOXR AND KSBA WITH IFR TO LOW MVFR CIGS. LOW CLOUDS SHOULD
ALSO MOVE INTO KBUR AND KVNY BY 11Z TO 12Z WITH MVFR CIGS. ALL THE
LOW CLOUDS ARE EXPECTED TO CLEAR TO VFR BY MIDDAY MON AND CONTINUE
VFR THRU MON AFTERNOON
FOR KLAX...MODERATE TO HI CONFIDENCE LOW CLOUDS AND MVFR CIGS WILL
MOVE IN BY 07Z THEN PERSIST THRU 19Z OR 20Z BEFORE CLEARING TO VFR
FOR THE REMAINDER OF THE DAY. NO WIND ISSUES ARE EXPECTED THRU MON.
FOR KBUR...MODERATE CONFIDENCE LOW CLOUDS AND MVFR CIGS WILL DEVELOP
BY 12Z MON THEN CLEAR TO VFR BY 18Z. NO WIND ISSUES ARE EXPECTED
THRU MON.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...SIRARD/KITTELL
AVIATION...SIRARD
WWW.WEATHER.GOV/LOSANGELES
[top]
000
FXUS66 KMTR 220351
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
850 PM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 8:50 PM PDT SUNDAY...THE FINAL FULL DAY OF
SUMMER WAS A BIT ON THE COOL SIDE OF NORMAL...WITH HIGH TEMPERATURES
ACROSS THE REGION ANYWHERE FROM 3 TO 8 DEGREES BELOW THE AVERAGE FOR
SEPT 21. AN UPPER LEVEL TROUGH CURRENTLY ALIGNED ALONG THE WEST COAST
WILL MOVE EAST INTO THE GREAT BASIN OVERNIGHT. IN ITS WAKE...SURFACE
HIGH PRESSURE WILL BUILD TO OUR NORTH AND THE FLOW WILL VEER FROM
NORTHWEST TO NORTH. SIGNS OF THIS PROCESS ARE ALREADY EVIDENT AS THE
THE ACV-SFO GRADIENT HAS BEEN INCREASING ALL DAY AND IS NEARLY AT 6
MB. A CONSEQUENCE OF THE INCREASING NORTHERLY GRADIENT HAS BEEN A
DECREASE IN LOW CLOUDS ALONG THE COAST AS STRONG NORTHWEST WINDS MIX
UP THE LOW LEVELS OUT OVER THE COASTAL WATERS. CURRENTLY...ONLY
PATCHY LOW CLOUDS REMAIN ALONG THE SAN MATEO COUNTY COAST AND ALONG
THE SOUTHERN PERIPHERY OF MONTEREY BAY. THE 12Z HIGH-RES WRF MODEL
HAS A GOOD HANDLE ON THE CURRENT LOW CLOUD COVERAGE AND ITS SHORT-
TERM FORECAST MAINTAINS MAINLY CLEAR SKIES FROM SAN FRANCISCO
NORTHWARD OVERNIGHT AND DECREASING CLOUDS ALONG THE SAN MATEO COUNTY
COAST. BUT THIS MODEL ALSO SHOWS INCREASING CLOUDS AROUND MONTEREY
BAY OVERNIGHT. THIS SEEMS REASONABLE GIVEN THAT THE N-S GRADIENT IS
MUCH WEAKER FARTHER TO THE SOUTH AND SO ONSHORE FLOW WILL BE MORE
PRONOUNCED NEAR MONTEREY BAY. NORTHERLY FLOW WILL GRADUALLY INCREASE
TO THE SOUTH ON MONDAY AND BY EARLY MONDAY AFTERNOON ALL AREAS SHOULD
BE SUNNY. NORTHERLY FLOW AND A WARMING AIRMASS ALOFT WILL RESULT IN
SEVERAL DEGREES OF WARMING ON MONDAY...WITH TEMPERATURES IN MOST
AREAS RETURNING TO NORMAL...AND EVEN A BIT ABOVE NORMAL IN THE NORTH
BAY. A GRADUAL WARMING TREND SHOULD CONTINUE THROUGH MIDWEEK AS A
FLAT UPPER RIDGE BUILDS OVER CA AND ONLY WEAK ONSHORE FLOW IS
FORECAST TO BE PRESENT AT THE SURFACE.
TEMPERATURES SHOULD TREND SLIGHTLY DOWNWARD DURING THE SECOND HALF
OF THE WEEK. BOTH THE GFS AND ECMWF MOVE THE RIDGE AXIS TO THE EAST
AND SHOW A COUPLE OF UPPER LEVEL SHORTWAVE TROUGHS MOVING INLAND TO
OUR NORTH...THE FIRST ON WEDNESDAY NIGHT AND THE SECOND ON FRIDAY.
GFS MOS GUIDANCE GENERALLY INDICATES A FEW DEGREES OF COOLING EACH
DAY FROM THURSDAY INTO NEXT WEEKEND. LOW CLOUDS WILL LIKELY RETURN TO
COASTAL AREAS SOMETIME DURING THE SECOND HALF OF THE WEEK...BUT AT
THIS POINT IT`S DIFFICULT TO PINPOINT EXACTLY WHEN THAT WILL OCCUR.
BOTH THE GFS AND ECMWF DEVELOP A WEAK CUTOFF LOW WEST OF BAJA BY
MIDWEEK. BUT THE MODELS DIVERGE WITH THIS FEATURE LATE IN THE
FORECAST PERIOD. THE 18Z GFS MOVES THE UPPER LOW TO THE NE...AND ALSO
BRINGS SOME SUBTROPICAL MOISTURE WITH IT. IF THE 18Z GFS VERIFIES...
WE COULD SEE SOME SHOWER/THUNDERSTORM ACTIVITY BY NEXT WEEKEND. BUT
THE 12Z ECMWF HOLDS THE UPPER LOW WELL TO OUR SOUTH AND BUILDS A
RIDGE OVER CA NEXT WEEKEND. THE ECMWF SOLUTION WOULD NOT ONLY
KEEP CONVECTIVE ACTIVITY WELL TO OUR SOUTH...BUT WOULD ALSO RESULT
IN WARMING NEXT WEEKEND. THIS IS AT THE VERY END OF OUR CURRENT
FORECAST PERIOD SO WILL AVOID MAKING ANY SIGNIFICANT CHANGES TO THE
EXTENDED FORECAST UNTIL THE MODELS COME INTO BETTER AGREEMENT.
&&
.AVIATION...AS OF 4:15 PM PDT SUNDAY...VFR/MVFR PREVAILS AT AREA
TERMINALS. THE BOUNDARY LAYER HAS FOR THE MOST PART MIXED OUT THIS
AFTERNOON LEAVING ONLY A FEW PATCHES OF STRATUS ON THE COAST. A 500
MB HEIGHT SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE BAY
AREA TONIGHT. FOR THE BAY AREA IT MAY ARRIVE EARLY ENOUGH TO KEEP
MIXING/DRYING GOING AND STRATUS CLOUDS TO A MINIMUM. HOWEVER FARTHER
SOUTH ACROSS THE CENTRAL COAST STRATUS CLOUDS PRESENTLY OBSERVED MAY
TEND TO STICK AROUND FOR THE EVENING. MVFR BASED CEILINGS ARE
FORECAST FOR KSNS AND KMRY. CLOSER TO MIDNIGHT CEILINGS ON THE
CENTRAL COAST MAY TEND TO BREAK APART AS THE TAIL END OF THE
SHORTWAVE TROUGH PASSES BY. VFR IS FORECAST ON MONDAY.
&&
.CLIMATE...AUTUMN BEGINS AT 8:44 AM PDT ON MONDAY SEPTEMBER 22.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: WJK/CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
[top]
000
FXUS66 KSGX 220337
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PDT SUN SEP 21 2008
.SYNOPSIS...THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF
COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND
MORNINGS...EXTENDING LOCALLY INLAND. OTHERWISE...FAIR AND GRADUALLY
WARMER THROUGH MID WEEK UNDER HIGH PRESSURE. A LITTLE COOLER TOWARD
THE WEEKEND AS THE HIGH WEAKENS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-WED)...SKIES WERE CLEAR THIS EVENING EXCEPT FOR
AREAS OF STRATUS NEAR THE COAST. THE 00Z NKX SOUNDING HAD A WEAK
INVERSION BASED NEAR 2100 FT WITH DRY WLY WINDS ALOFT. ONSHORE
GRADIENTS WITH ABOUT 7 MB SAN-IPL.
THE TROUGH OVER THE W WILL MOVE E EARLY MON AND HIGH PRESSURE WILL
BUILD ALOFT THROUGH WED. THE MARINE LAYER WILL BE MODERATELY DEEP
TONIGHT WITH LOW CLOUDS AND LOCAL FOG GETTING INTO MOST SAN DIEGO
INLAND VALLEYS AND THE WRN INLAND EMPIRE...BUT NOT QUITE AS FAR
INLAND AS LAST NIGHT. SUBSIDENCE WILL MAKE THE MARINE LAYER
SHALLOWER MON AND TUE NIGHTS FOR LESS INLAND PENETRATION.
OTHERWISE...FAIR IN DRY W TO SW WINDS ALOFT. A LITTLE WARMER MON
THEN MORE WARMING TUE AND WED. MAX TEMPS WILL REMAIN BELOW SEASONAL
AVERAGES IN MOST AREAS MON AND BECOME ABOUT 4 TO 8 DEGREES ABOVE
SEASONAL IN THE INLAND AREAS BY WED.
&&
.LONG TERM (THU-SUN)...LITTLE CHANGE ON THU. HIGH PRESSURE WILL
SHIFT E AS A WEAK TROUGH OF LOW PRESSURE MOVES THROUGH FRI AND SAT.
THIS WILL BRING COOLER WEATHER AND A DEEPER MARINE LAYER WITH
INCREASING LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS. WARMER
EARLY NEXT WEEK AS HIGH PRESSURE BUILDS ALOFT AGAIN. MODELS HAVE
BEEN INDICATING A POSSIBLE INCREASE IN MID LEVEL MOISTURE BUT HAVE
BEEN INCONSISTENT DURING THE EXTENDED PERIOD. THERE WILL PROBABLY
MORE CLOUDS...MAINLY IN THE FORM OF AFTERNOON CU OVER THE MOUNTAINS.
NO AFTERNOON THUNDERSTORMS ARE EXPECTED IN THE MOUNTAINS AND DESERTS
AT THIS TIME...BUT CANNOT COMPLETELY RULE OUT A SMALL CHANCE.
&&
.AVIATION...
220300Z...MARINE INVERSION WAS AROUND 1900 FT MSL AND IS EXPECTED TO
LOWER SLIGHTLY OVERNIGHT. STRATUS OVER THE COASTAL WATERS SHOULD
REACH THE COAST BETWEEN 04Z AND 05Z AND EVENTUALLY SPREAD 15-20
MILES INLAND BY 12Z. STRATUS BASES WILL LOWER TO ABOUT 1500 FT MSL
BY 12Z. STRATUS PROBABLY WILL NOT REACH MUCH IF ANY OF THE INLAND
EMPIRE...THOUGH SOME 2-3 MILE VSBYS COULD OCCUR IN FAR W AND S
SECTIONS. CLEARING SHOULD OCCUR BY 17Z MON IN MOST AREAS. ABOVE THE
MARINE LAYER...NO CIG/VIS RESTRICTIONS ARE EXPECTED.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...MAXWELL
[top]
000
FXUS66 KEKA 220042
AFDEKA
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE EUREKA CA
545 PM PDT SUN SEP 21 2008
.SYNOPSIS...HIGH PRESSURE BUILDING OVER THE PACIFIC WILL BRING A
WARMING TREND TO INTERIOR LOCATIONS FOR THE NEXT FEW DAYS. LATE
NIGHT AND MORNING LOW CLOUDS ARE EXPECTED TO CONTINUE NEAR THE COAST
THROUGH MIDWEEK.
&&
.SHORT TERM...VISIBLE SATELLITE IMAGERY SHOWS CU BUILD-UPS OVER THE
HIGHER TERRAIN OF DEL NORTE AND TRINITY COUNTIES. ISOLATED SHOWERS
AND THUNDERSTORMS ARE OCCURRING OVER SISKIYOU AND SHASTA COUNTIES.
SREF INSTABILITY PLOTS INDICATE AS MUCH AS A 50 PERCENT PROBABILITY
OF NEGATIVE LI`S OVER THESE AREAS PERSISTING THROUGH LATE
AFTERNOON...AND GFS AND NAM GUIDANCE INDICATE LIMITED INSTABILITY AS
WELL. IN LIGHT OF THESE FACTORS...HAVE INCLUDED A SLIGHT CHANCE OF
SHOWERS AND TSTMS FOR THE HIGHER TERRAIN OF ZONES 3 AND 4 THROUGH
THIS EVENING.
SEVERAL STATIONS ACROSS THE NORTH COAST INTERIOR AND MENDOCINO
INTERIOR ARE SHOWING A SLIGHT WARMING TREND COMPARED TO THIS TIME
YESTERDAY. EXPECT THE WARMING TREND TO CONTINUE INTO MONDAY AS H5
HEIGHTS BUMP UP AROUND 6-8 DM OVER THE NEXT 24 HOURS. TEMPS WILL
STILL BE BELOW SEASONAL NORMALS WITH INLAND VALLEY HIGHS RUNNING
GENERALLY IN THE LOW 80S. HEIGHTS WILL CONTINUE TO RISE INTO
TUESDAY AND CONTINUE THE WARM-UP FOR THE INTERIOR WITH HIGHS
REACHING NEAR-NORMAL VALUES. NIGHTTIME LOWS WILL BE COOLER THE NEXT
COUPLE NIGHTS UNDER CLEAR SKIES. AT THE COAST...THE MARINE LAYER
INFLUENCE WILL CONTINUE WITH NIGHT AND MORNING LOW CLOUDS EXPECTED
THROUGH TUESDAY.
HIGH PRESSURE WILL BE SHIFTED INTO THE DESERT SOUTHWEST AROUND
MIDWEEK AS A TROUGH TRACKS EAST ACROSS THE NORTHEAST PACIFIC INTO
THE WEST COAST. THIS SYSTEM WILL BEGIN SPREADING CLOUDS INTO THE
NORTHERN PORTION OF THE CWA BY WEDNESDAY AFTERNOON ALONG WITH THE
POSSIBILITY OF LIGHT PRECIP ACROSS DEL NORTE COUNTY. KL
.LONG TERM...THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE MODELS ARE
SHOWING ONLY FAIR AGREEMENT IN THE DEPICTION OF UPPER LEVEL FLOW
EVOLUTION...STARTING THURSDAY WITH A SHORTWAVE RIDGE OVER THE
CANADIAN COAST AND A BAGGY TROUGH NEAR THE CALIFORNIA COAST. THERE
IS GENERAL AGREEMENT IN THE IDEA OF PUSHING A TROUGH TOWARD THE
PACIFIC NORTHWEST FRIDAY AFTERNOON...AS A STRONGER LOW MOVES INTO
THE GULF OF ALASKA ACROSS THE ALEUTIAN ISLANDS. MADE FEW CHANGES TO
THE EXTENDED IN THIS AFTERNOON`S PACKAGE...AND WILL LOOK FOR BETTER
MODEL CONSISTENCY IN COMING RUNS. CMC
&&
.AVIATION...ALTO CU OVER DEL NORTE AND THE TRINITY ALPS WILL CLEAR
AFTER SUNSET. CLEAR SKIES WITH VFR CONDITIONS WILL PREVAIL
TONIGHT...EXCEPT ALONG THE NORTH COAST WHERE LOW MARINE CLOUDS WILL
BRING PERIODS OF IFR CONDITIONS. TH
&&
.MARINE...THE PASSAGE OF THE WEAK TROUGH TODAY HAS DELAYED THE
INCREASE OF NORTHERLY WINDS OVER THE NORTHERN WATERS. THE SOUTHERN
WATERS WERE LESS INFLUENCED BY THE TROUGH AND SCATTEROMETER AND BUOY
DATA SHOW THE WINDS HAVE INCREASED TODAY. WINDS WILL INCREASE OVER
ALL WATERS TONIGHT AND MONDAY WITH SCA CONDITIONS EXTENDING TO THE
NORTHERN OUTER WATERS MON MORNING. ALTHOUGH WIND GUSTS MAY LOCALLY
REACH GALE FORCE STRENGTH DO NOT ANTICIPATE THE GALE GUSTS WILL LAST
LONG OR BE WIDESPREAD. THE SEAS WILL BE CHOPPY AND STEEP MON NIGHT
THROUGH TUE MORNING WHEN THE PRESSURE GRADIENT WILL BE TIGHTEST OVER
THE WATERS. THE WINDS WILL BEGIN TO EASE TUE NIGHT AS A WEAK FRONT
APPROACHES THE REGION AND REMAIN LIGHT UNTIL THE FRONT PUSHES
THROUGH WED NIGHT. W-NW SWELL TRAIN WITH THIS SYSTEM WILL BEGIN TO
BUILD OVER THE REGION MID TO LATE WEDNESDAY. TH
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR WINDS AND HAZARDOUS SEAS FROM CAPE
MENDOCINO TO POINT ARENA OUT 10 TO 60 NM.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
[top]
000
FXUS65 KREV 220027
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
527 PM PDT SUN SEP 21 2008
.UPDATE...
UPDATE FOR THE CURRENT TRENDS IN SATELLITE AND RADAR. BAROCLINIC
ZONE SITTING ACROSS THE NORTHERN AREAS...FROM LASSEN PARK TO THE
BLACK ROCK DESERT. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
ARE DEVELOPING ALONG AND BEHIND THE BAROCLINC ZONE. STRONG WAVE
WITH RIGHT ENTRANCE REGION OF THE JET IS PROVIDING THE LIFT WITH
COOLING TEMPERATURES ALOFT GENERATING THE INSTABILITY. MOST OF THE
LIGHTNING HAS OCCURRED OVER SISKIYOU AND MODOC...WHERE THE
INFLUENCE OF THE COLD POOL IS GREATEST.
18Z NAM HAS A GOOD HANDLE ON THE SITUATION AND HAS A MORE
SOUTHWARD EXTENT FOR THE SHOWER AND THUNDERSTORMS CHANCES. THE NAM
BRINGS THE WAVE DOWN TO OVER RENO-CARSON AROUND MIDNIGHT...HOWEVER
THE MOISTURE STAYS NORTH OF I-80...EXCEPT OVER PERSHING AND
NORTHERN CHURCHILL COUNTY. THUS HAVE PULLED ISOLATED SHOWERS DOWN
TO A SUSANVILLE-NORTH SHORE PYRAMID LAKE-LOVELOCK LINE. ALSO
EXTENDED THE TIMING OF THE THUNDERSTORMS FOR ANOTHER FEW HOURS AS
THE CELLS OVER SISKIYOU AND MODOC TRACK INTO LASSEN AND NORTHERN
WASHOE OVER THE NEXT FEW HOURS. BRONG
&&
.AVIATION UPDATE...
ONLY CHANGE FROM THE DISCUSSION BELOW WAS TO ADD VCSH TO LOVELOCK
AS SHOWERS STARTING TO DEVELOP A BIT FARTHER SOUTH. O`HARA/BRONG
&&
.PREVIOUS DISCUSSION... /ISSUED 100 PM PDT SUN SEP 21 2008/
SHORT TERM...
PRIMARY ISSUE FOR TODAY WAS GAGING THE IMPACT OF APPROACHING UPPER
LEVEL TROF AND JET STREAK, CLEARLY EVIDENT IN THE WATER VAPOR MOVING
INTO NW CA AS OF 18Z. WHAT`S REALLY INTERESTING IS THAT THE JET CORE
SHOWS UP WELL IN THE 250MB GEFS WIND ANOMALY FIELDS (~2SD ABOVE
NORMAL FOR THE ZONAL COMPONENT). BOTH THE GFS AND NAM SHOW STRONG
LIFT ASSOC WITH AMPLIFYING WAVE AND LEFT EXIT REGION OF JET
STREAK...AFFECTING NORTHERN 1/3 OF OUR CWA TONIGHT. THE 9Z SREF
BULKED UP ON QPF ASSOC WITH TROF TONIGHT COMPARED TO 3Z RUN. TO
CONTRAST THAT, LOCAL WRF USING THE NAM BOUNDARY CONDS IS
SURPRISINGLY DRY.
AM FIGURING WITH THE STRONG DYNAMICS, THAT WILL OVERCOME ANY LACK OF
INSTABILITY AND LOW LVL MOISTURE TO PRODUCE ISOLD-SCT SHRA LATE THIS
AFTERNOON THROUGH MIDNIGHT ROUGHLY NORTH OF A SVE-LOL LINE. WILL
RETAIN CHC OF THUNDER, GIVEN STRONG DYNAMICS AND COOLING TEMPS ALOFT
(MORE GRAUPEL/CHARGED PARTICLES...A COUPLE CC`S OR CG`S ARE
POSSIBLE). BASED ON SOUNDING WET BULB PROFILES, SNOW LEVELS WILL
DROP BELOW 8KFT TONIGHT UP NORTH, AND THOUGH NOT IN OUR CWA SOME
LIGHT SN POSSIBLE IN WARNERS OF NE CA.
WINDS ALOFT WILL REMAIN STRONG THROUGH MONDAY MORNING AS UPPER JET
TRACKS OVER THE REGION. GEFS 700MB WIND ANOMALIES ARE CLOSE TO 1 SD
ABOVE NORMAL THROUGH THIS EVENING. EXTREMELY DRY AIR ALOFT FORECAST
TO ADVECT INTO THE SIERRA LATE TONIGHT. THIS AIR WILL EVENTUALLY MIX
DOWNWARD MON AFTN INTO MON NIGHT, SUCH THAT RH RECOVERIES TUES
MORNING WILL LIKELY BE POOR FOR MANY AREAS. THIS EVEN SHOWS UP IN
THE NAEFS METEOGRAM AT RNO!
INTO MID-WEEK, FLOW ALOFT WILL BECOME MORE ZONAL WITH INCREASING
HEIGHTS. A GRADUAL WARMING TREND IS EXPECTED AS A RESULT. LOW
CURRENTLY EXHIBITING A NICE BAROCLINIC LEAF SIGNATURE BETWEEN 150
AND 160W IS FORECAST BY GEFS AND ECMWF TO MOVE NEAR THE PAC NW/BC ON
WED. PRECIP ASSOC WITH THAT SYSTEM WILL REMAIN WELL N OF THE CWA,
HOWEVER 700MB WIND FIELDS IN GEFS DO INDICATE AT LEAST AN INCREASE
IN WIND FOR WED.
CS
LONG TERM...THURSDAY THROUGH SUNDAY...
QUIET WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE
EXTENDED. THE MEDIUM RANGE MODELS CONTINUE TO SHOW A SYSTEM MOVING
TOWARD THE WEST COAST ON THURSDAY. THE GFS FORMS A DEEPER TROUGH
THAN DOES THE ECMWF AND THIS WOULD AFFECT HOW MUCH SLY FLOW AND
MOISTURE ADVECTION WE WOULD SEE AHEAD OF THE SYSTEM. ON FRIDAY THE
GFS IS MORE AGGRESSIVE IN DIGGING THIS UPPER TROUGH SOUTH TO AROUND
30N 130W. THE ECMWF KEEPS A MORE ZONAL FLOW ACROSS THE WEST COAST
WITH THE SWRN RIDGE EXTENDING WEST INTO THE ERN PACIFIC. BECAUSE OF
THIS UNCERTAINTY IN THE MODEL SOLUTIONS HAVE DECIDED TO KEEP FRIDAY
DRY FOR NOW. HOWEVER DID INCREASE CLOUD COVER SOME BUT KEPT POPS
BELOW 10 PERCENT. THESE ELEMENTS CAN BE ADJUSTED UPWARD IF THE
MODEL SOLUTIONS START TO CONVERGE TOWARD A WET PATTERN.
AS THIS FIRST WEAK TROUGH PUSHES TO THE EAST LATE IN THE WEEK BOTH
THE GFS AND THE EURO SHOW A DEEPENING UPPER TROUGH MOVING INTO THE
GULF OF ALASKA ON SATURDAY AND THEN DIGGING SOUTH ON SUNDAY. THIS
COULD BECOME A SIGNIFICANT SYSTEM AND WOULD AFFECT THE KREV CWFA
EARLY NEXT WEEK SO ITS EVOLUTION WILL CONTINUE TO BE WATCHED. O`HARA
AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH MONDAY. GUSTY WINDS EXPECTED
THIS AFTN AND EVENING WITH GUSTS TO 30 KTS POSSIBLE. ISOLD TSRA
ALSO POSSIBLE THIS EVENING ACROSS FAR NWRN NEVADA AND FAR NERN
CALIFORNIA MAINLY THROUGH 06Z. O`HARA
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KLOX 212358 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
500 PM PDT SUN SEP 21 2008
UPDATE TO ADD NEW AVIATION DISCUSSION
.SHORT TERM (TODAY-WEDNESDAY)...
MOST OF THE AREA RUNNING A BIT COOLER THAN YESTERDAY THANKS TO A
SLIGHTLY INCREASED MARINE INFLUENCE. THE MOUNTAINS AND DESERTS
HOWEVER ARE SEEING WARMER TEMPS THANKS TO THE STRONGER INVERSION AND
THE PASSAGE OF THE COLD AIR ALOFT THAT MOVED IN YESTERDAY. STRATUS
HAS CLEARED FOR THE MOST PART THIS AFTERNOON...BUT IT LOOKS PRIMED
FOR ANOTHER REPEAT TOMORROW...AS ANOTHER EDDY FORMS SOUTH OF POINT
CONCEPTION AND LITTLE CHANGE EXPECTED TO THE NORTH.
WIND-WISE...ONLY CONCERN IS FOR ONE MORE ROUND OF GUSTY BUT
SUB-ADVISORY NORTHERLY FLOW THROUGH THE I5 CORRIDOR TONIGHT. LOOKS
LIKE ONE MORE ROUND OF FALL-LIKE CHILLY OVERNIGHT LOW TEMPS
TONIGHT...BUT THOSE TEMPS SHOULD INCREASE AFTER TONIGHT AS THE
AIRMASS BEGINS TO WARM UP.
THE WARMING TREND STILL LOOKS GOOD MON THRU WED. 12Z GFS STILL
SLOWLY BUILDS A HEALTHY 590 DM RIDGE UP FROM THE SOUTH THROUGH THIS
PERIOD. FOR LAST FEW DAYS...THE MODELS HAVE BEEN ADVERTISING A WEAK
LOW OFF TO OUR WEST...BUT THE 00Z AND 12Z RUNS HAVE WEAKENED THIS
LOW EVEN MORE...ALLOWING THE HIGH TO BUILD FURTHER WESTWARD.
ALTHOUGH THIS SOLUTION WILL LIKELY GO THROUGH A FEW MORE CHANGES
OVER THE NEXT RUNS...THE PICTURE IS SHAPING UP WELL FOR THE TIMING
AND GENERAL MAGNITUDE OF THE WARMING TREND. ADDING TO THE WARMING IS
A GRADUAL WEAKENING OF THE ONSHORE GRADS. IN FACT...THE NAM SHOWS A
0.0MB LAX-DAG GRAD WED MORNING. THIS IS DUE TO SOME WEAK HIGH
PRESSURE OVER COLORADO AND THE WARM TEMPS TO THE NORTH INDUCING AN
INVERTED SURFACE TROUGH ALONG THE CA COAST. ALL THIS POINTS TO A
RATHER WARM WED AND FORECAST WAS ADJUSTED UP A FEW DEGREES IN MOST
PLACES...ESPECIALLY THE LA/VTU VALLEYS. WED COULD BE EVEN WARMER IF
THE HIGH BUILDS FURTHER WEST...AND ONSHORE GRADS DO NOT QUICKLY
SWING BACK ONSHORE IN THE AFT AS THE NAM IS TRYING TO SHOW. THE
MARINE LAYER WILL GRADUALLY SQUASH DOWN WITH HEIGHTS BUILDING AND
THE EDDY DYING AFTER MON. KEPT STRATUS ALONG ALL THE IMMEDIATE
COASTAL SPOTS BY TUE...BUT LIKELY REALITY IS THAT EVEN SOME COASTAL
SPOTS WILL STAY STRATUS FREE.
.LONG TERM (THURSDAY-SUNDAY)...
MODELS HAVE BEEN FLIP FLOPPING A BIT FOR THU AND FRI. A TROUGH
SHOULD DIG DOWN FROM ALASKA AND PUSH OUR WARM RIDGE EASTWARD...BUT
WHETHER THAT HAPPENS THU NIGHT LIKE THE 0Z RUNS SUGGESTED OR FRI
NIGHT LIKE THE 12Z RUNS IS LEFT TO BE SEEN. THE 12Z RUNS ACTUALLY
WEAKEN THE ORIGINAL TROUGH...WHILE A RATHER LARGE TROUGH JUST SOUTH
OF ALASKA STEALS SOME OF ITS ENERGY. THIS NEW SOLUTION RESULTS IN
SHIFTING THE HIGH ONLY SLIGHTLY TO THE EAST...AND KEEPING US FAIRLY
WARM FRI THROUGH SUN. NOT ONLY THAT...BUT THIS PATTERN PUTS THE HIGH
INTO A FAVORABLE SOUTHERLY FLOW REGIME FOR OUR AREA...WHICH COULD
PULL UP ANY AVAILABLE MOISTURE FROM MEXICO. DID NOT BITE ON THIS
JUST YET...SINCE THIS MOISTURE WOULD NOT GET HERE UNTIL FRIDAY...BUT
IF THE MODELS CONTINUE TO SING THE SAME TUNE THROUGH THIS WEEK...IT
WILL BE TOUGH TO IGNORE FOR LONG. EITHER WAY...FRI THROUGH SUN
SHOULD BE A BIT COOLER...BUT UNTIL WERE SEE MORE STABILITY IN THE
SOLUTIONS...DID NOT GET TOO CUTE AND JUST TRENDED TEMPS DOWN A BIT
EACH DAY BACK TOWARD NORMAL.
&&
.AVIATION...21/2345Z...NOT MUCH IN THE WAY OF ORGANIZED LOW CLOUD
COVER OVER THE COASTAL WATERS LATE THIS AFTERNOON...ALTHO LOW CLOUDS
DID DEVELOP INLAND OVER THE SOUTHERN PORTION OF THE SBA CENTRAL
COAST. LOW CLOUDS SHOULD EVENTUALLY DEVELOP OVER A WIDER PORTION OF
THE CENTRAL COAST TONIGHT AND MOVE INTO KSMX AND KSBP BY MIDNIGHT OR
SHORTLY AFTER. THE WRF WAS FORECASTING LIGHT OFFSHORE FLOW FOR THIS
AREA LATER TONIGHT SO IT IS POSSIBLE ANY LOW CLOUDS THAT DO MOVE
INTO THE AIRFIELDS MAY CLEAR OUT AS EARLY AS 7 AM OR 8 AM. LOW
CLOUDS ALSO EXPECTED TO DEVELOP AROUND KPRB LATE TONIGHT AND EARLY
MON.
S OF POINT CONCEPTION...TIMING OF LOW CLOUDS RATHER DIFFICULT...BUT
IT LOOKS LIKE THE LOW CLOUDS SHOULD MOVE INTO KLGB AND KLAX BY 07Z
OR 08Z AS AN EDDY DEVELOPS...THEN SPREAD UP THE COAST AND EVENTUALLY
AFFECT KOXR AND KSBA WITH IFR TO LOW MVFR CIGS. LOW CLOUDS SHOULD
ALSO MOVE INTO KBUR AND KVNY BY 11Z TO 12Z WITH MVFR CIGS. ALL THE
LOW CLOUDS ARE EXPECTED TO CLEAR TO VFR BY MIDDAY MON AND CONTINUE
VFR THRU MON AFTERNOON
FOR KLAX...MODERATE TO HI CONFIDENCE LOW CLOUDS AND MVFR CIGS WILL
MOVE IN BY 07Z THEN PERSIST THRU 19Z OR 20Z BEFORE CLEARING TO VFR
FOR THE REMAINDER OF THE DAY. NO WIND ISSUES ARE EXPECTED THRU MON.
FOR KBUR...MODERATE CONFIDENCE LOW CLOUDS AND MVFR CIGS WILL DEVELOP
BY 12Z MON THEN CLEAR TO VFR BY 18Z. NO WIND ISSUES ARE EXPECTED
THRU MON.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL
AVIATION...SIRARD
WWW.WEATHER.GOV/LOSANGELES
[top]
000
FXUS65 KPSR 212356
AFDPSR
AREA FORECAST DISCUSSION...AVIATION SECTION UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
456 PM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...AVIATION SECTION UPDATED.
&&
.SYNOPSIS...
MOSTLY CLEAR SKIES CAN BE EXPECTED THIS WEEK AS A RIDGE OF HIGH
PRESSURE BECOMES CENTERED OVER THE SOUTHWEST. A FEW DEGREES OF
WARMING CAN BE EXPECTED BY WEDNESDAY WITH TEMPERATURES REMAINING
ABOVE AVERAGE INTO NEXT WEEKEND.
&&
.DISCUSSION...
CONSIDERABLY LESS CLOUDINESS OVER SOUTH-CENTRAL ARIZONA THIS
AFTERNOON THAN YESTERDAY. SURFACE DEW POINTS ARE RUNNING SEVERAL
DEGREES LOWER EARLY THIS AFTERNOON AS COMPARED TO 24 HOURS AGO. ONLY
REAL CUMULUS DEVELOPMENT HAS BEEN OVER ZONE 24 BUT WITH LIMITED
VERTICAL DEVELOPMENT. CONVECTION IS ANTICIPATED TO REMAIN SHALLOW
AND THUS DROPPED THE VERY MODEST POPS WE HAD OVER ZONE 24 FOR THE
AFTERNOON PACKAGE.
AS PREVIOUSLY DISCUSSED...PROGS SHOW A CONTINUED DECLINE IN MOISTURE
FROM WEST TO EAST FOR VERY LITTLE IF ANY CLOUDINESS THE NEXT FEW
DAYS. TROUGHS PASSING TO THE NORTH DURING THE NEXT 24-36 HOURS WILL
LEAD TO SOME LOCALIZED BREEZINESS BUT THEY WILL BE TOO FAR NORTH TO
GENERATE MUCH IN THE WAY OF STRONG SURFACE WINDS OVER OUR AREA.
RIDGE BUILDING INTO THE AREA TUESDAY AND WEDNESDAY WILL LEAD TO AT
LEAST A FEW DEGREES OF WARMING MOST PLACES.
DURING THE LATTER HALF OF THE WEEK...PROGS IN GOOD AGREEMENT THAT
THE RIDGE WILL REMAIN CENTERED OVER THE SOUTHERN ROCKIES THROUGH
FRIDAY AS A PACIFIC TROUGH SLOWLY ADVANCES EASTWARD. ANTICIPATE
SLIGHT COOLING OVER NEXT WEEKEND PER GFS AND GFS ENSEMBLE MEAN AS A
SOUTHERN BRANCH TROUGH MOVES INTO THE CALIFORNIA COAST. THIS WOULD
ALSO LEAD TO MORE NOTICEABLE AFTERNOON AND EVENING BREEZES.
&&
.AVIATION...
DRY AIR THAT HAS WORKED INTO THE REGION WILL KEEP SKIES MOSTLY CLEAR
OVER THE ENTIRE REGION THROUGH MONDAY MORNING. A FEW CUMULUS CLOUDS
ARE THEN EXPECTED TO DEVELOP OVER PORTIONS OF EAST CENTRAL ARIZONA
AS THE SURFACE HEATS UP IN THE AFTERNOON. CLOUD BASES WILL BE AROUND
100 KFT.
A LOW LEVEL JET STILL APPEARS TO BE BRINGING SOME GUSTY SURFACE
WINDS INTO SOUTH-CENTRAL ARIZONA. WINDS...HOWEVER...AT KPHX AND KIWA
ARE NOT EXPECTED TO BE IMPACTED...AND WILL REMAIN LIGHT OUT OF THE
SOUTHWEST THROUGH EARLY MONDAY MORNING. STANDARD EAST DRAINAGE WINDS
WILL THEN DEVELOP AT BOTH AIRFIELDS AROUND 09Z.
IN THE WEST-CENTRAL ARIZONA AND SOUTHEAST CALIFORNIA DESERTS...WINDS
AT KYUM AND KIPL WILL FAVOR A SOUTHWEST DIRECT THIS EVENING...BUT
THEN BECOME LIGHT AND VARIABLE OVERNIGHT. GUSTY SOUTHWEST WINDS ARE
EXPECTED AT KBLH EARLY THIS EVENING...BUT WILL BECOME LIGHT AND
VARIABLE OVERNIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...MCLANE
FIRE WEATHER...SIPPLE
000
FXUS66 KMTR 212315
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
415 PM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 2:30 PM PDT SUNDAY...WARMER FOR THE MIDDLE PART
OF THIS WEEK.
TEMPERATURES HAVE WARMED UP CLOSE TO WHAT WE HIT YESTERDAY WITH
VIRTUALLY ALL SPOTS IN THE 60S AND 70S. VISIBLE SATELLITE LOOP
SHOWS MOST PLACES NEARLY CLOUD FREE EXCEPT RIGHT AT THE COAST FROM
SAN FRANCISCO TO DOWN TO PEBBLE BEACH WITH A LARGE CLEAR AREA
AROUND SANTA CRUZ. OVERALL THE HIGH RESOLUTION WRF HAS DONE A GOOD
JOB HANDLING CLOUDS ACROSS OUR AREA AND WAS HEAVILY USED FOR THE
CLOUD PORTION OF THE FORECAST. WITH THE NORTHERLY GRADIENT TWICE THE
ONSHORE COMPONENT...MOSTLY CLEAR SKIES SHOULD REMAIN OVER THE
INTERIOR. THE COAST SOUTH OF SANTA CRUZ WILL NOT FARE SO WELL AS THE
FLOW SHOULD KEEP CLOUDS GOING INTO THE OVERNIGHT HOURS. FOR NORTH OF
SANTA CRUZ ALONG THE COAST IT IS A TOUGHER CALL. THE WRF BRINGS
CLOUDS BACK INTO PART OF THE AREA ALTHOUGH IT IS QUITE POSSIBLE THAT
THE FLOW WILL PUSH THE LINE OF CLOUDS SOUTH OF SANTA CRUZ. FOR THE
FORECAST...DECIDED TO GO WITH CLOUDY SKIES OVERNIGHT OVER THE COAST
OF SOUTHERN MONTEREY WITH JUST MOSTLY CLEAR TO PARTLY CLOUDY SKIES
NORTH OF SANTA CRUZ.
OVERALL...THE WEEK IS SHAPING UP TO BE QUIET WITH ALL OF THE MAJOR
MODELS KEEPING THE STORM TRACK WELL TO THE NORTH WHILE A RIDGE
RETURNS TO OUR AREA. TEMPERATURES WILL INCREASE EACH DAY THIS WEEK AT
LEAST THROUGH WEDNESDAY WHICH WILL BRING THEM BACK TO ABOVE NORMAL
READINGS OVER THE INTERIOR PORTIONS IN PARTICULAR. EVEN WITH THE
WARMER WEATHER...TEMPERATURES SHOULD STILL FALL WELL SHORT OF ANY
HEAT RELATED CRITERIA. BEYOND WEDNESDAY THERE IS DISAGREEMENT
AS ONE GROUP KEEPS THE RIDGE OVERHEAD WHILE ANOTHER SHOWS A PACIFIC
TROUGH MOVING IN HELPING TO DISPLACE THE RIDGE. UNTIL A BETTER
CONSENSUS IS REACHED THE TEMPERATURES IN THE GIRDS WERE NOT GREATLY
CHANGED WHICH PRODUCED HIGHS CLOSE TO NORMAL.
&&
.AVIATION...AS OF 4:15 PM PDT SUNDAY...VFR/MVFR PREVAILS AT AREA
TERMINALS. THE BOUNDARY LAYER HAS FOR THE MOST PART MIXED OUT THIS
AFTERNOON LEAVING ONLY A FEW PATCHES OF STRATUS ON THE COAST. A 500
MB HEIGHT SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE BAY
AREA TONIGHT. FOR THE BAY AREA IT MAY ARRIVE EARLY ENOUGH TO KEEP
MIXING/DRYING GOING AND STRATUS CLOUDS TO A MINIMUM. HOWEVER FARTHER
SOUTH ACROSS THE CENTRAL COAST STRATUS CLOUDS PRESENTLY OBSERVED MAY
TEND TO STICK AROUND FOR THE EVENING. MVFR BASED CEILINGS ARE
FORECAST FOR KSNS AND KMRY. CLOSER TO MIDNIGHT CEILINGS ON THE
CENTRAL COAST MAY TEND TO BREAK APART AS THE TAIL END OF THE
SHORTWAVE TROUGH PASSES BY. VFR IS FORECAST ON MONDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: WJK/CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KEKA 212253
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
354 PM PDT SUN SEP 21 2008
.SYNOPSIS...HIGH PRESSURE BUILDING OVER THE PACIFIC WILL BRING A
WARMING TREND TO INTERIOR LOCATIONS FOR THE NEXT FEW DAYS. LATE
NIGHT AND MORNING LOW CLOUDS ARE EXPECTED TO CONTINUE NEAR THE COAST
THROUGH MIDWEEK.
&&
.SHORT TERM...VISIBLE SATELLITE IMAGERY SHOWS CU BUILD-UPS OVER THE
HIGHER TERRAIN OF DEL NORTE AND TRINITY COUNTIES. ISOLATED SHOWERS
AND THUNDERSTORMS ARE OCCURRING OVER SISKIYOU AND SHASTA COUNTIES.
SREF INSTABILITY PLOTS INDICATE AS MUCH AS A 50 PERCENT PROBABILITY
OF NEGATIVE LI`S OVER THESE AREAS PERSISTING THROUGH LATE
AFTERNOON...AND GFS AND NAM GUIDANCE INDICATE LIMITED INSTABILITY AS
WELL. IN LIGHT OF THESE FACTORS...HAVE INCLUDED A SLIGHT CHANCE OF
SHOWERS AND TSTMS FOR THE HIGHER TERRAIN OF ZONES 3 AND 4 THROUGH
THIS EVENING.
SEVERAL STATIONS ACROSS THE NORTH COAST INTERIOR AND MENDOCINO
INTERIOR ARE SHOWING A SLIGHT WARMING TREND COMPARED TO THIS TIME
YESTERDAY. EXPECT THE WARMING TREND TO CONTINUE INTO MONDAY AS H5
HEIGHTS BUMP UP AROUND 6-8 DM OVER THE NEXT 24 HOURS. TEMPS WILL
STILL BE BELOW SEASONAL NORMALS WITH INLAND VALLEY HIGHS RUNNING
GENERALLY IN THE LOW 80S. HEIGHTS WILL CONTINUE TO RISE INTO
TUESDAY AND CONTINUE THE WARM-UP FOR THE INTERIOR WITH HIGHS
REACHING NEAR-NORMAL VALUES. NIGHTTIME LOWS WILL BE COOLER THE NEXT
COUPLE NIGHTS UNDER CLEAR SKIES. AT THE COAST...THE MARINE LAYER
INFLUENCE WILL CONTINUE WITH NIGHT AND MORNING LOW CLOUDS EXPECTED
THROUGH TUESDAY.
HIGH PRESSURE WILL BE SHIFTED INTO THE DESERT SOUTHWEST AROUND
MIDWEEK AS A TROUGH TRACKS EAST ACROSS THE NORTHEAST PACIFIC INTO
THE WEST COAST. THIS SYSTEM WILL BEGIN SPREADING CLOUDS INTO THE
NORTHERN PORTION OF THE CWA BY WEDNESDAY AFTERNOON ALONG WITH THE
POSSIBILITY OF LIGHT PRECIP ACROSS DEL NORTE COUNTY. KL
.LONG TERM...THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE MODELS ARE
SHOWING ONLY FAIR AGREEMENT IN THE DEPICTION OF UPPER LEVEL FLOW
EVOLUTION...STARTING THURSDAY WITH A SHORTWAVE RIDGE OVER THE
CANADIAN COAST AND A BAGGY TROUGH OF SHORTS NEAR THE CALIFORNIA
COAST. THERE IS GENERAL AGREEMENT IN THE IDEA OF PUSHING A TROUGH
TOWARD THE PACIFIC NORTHWEST FRIDAY AFTERNOON...AS A STRONGER LOW
MOVES INTO THE GULF OF ALASKA ACROSS THE ALEUTIAN ISLANDS. MADE FEW
CHANGES TO THE EXTENDED IN THIS AFTERNOON`S PACKAGE...AND WILL LOOK
FOR BETTER MODEL CONSISTENCY IN COMING RUNS. CMC
&&
.AVIATION...ALTO CU OVER DEL NORTE AND THE TRINITY ALPS WILL CLEAR
AFTER SUNSET. CLEAR SKIES WITH VFR CONDITIONS WILL PREVAIL
TONIGHT...EXCEPT ALONG THE NORTH COAST WHERE LOW MARINE CLOUDS WILL
BRING PERIODS OF IFR CONDITIONS. TH
&&
.MARINE...THE PASSAGE OF THE WEAK TROUGH TODAY HAS DELAYED THE
INCREASE OF NORTHERLY WINDS OVER THE NORTHERN WATERS. THE SOUTHERN
WATERS WERE LESS INFLUENCED BY THE TROUGH AND SCATTEROMETER AND BUOY
DATA SHOW THE WINDS HAVE INCREASED TODAY. WINDS WILL INCREASE OVER
ALL WATERS TONIGHT AND MONDAY WITH SCA CONDITIONS EXTENDING TO THE
NORTHERN OUTER WATERS MON MORNING. ALTHOUGH WIND GUSTS MAY LOCALLY
REACH GALE FORCE STRENGTH DO NOT ANTICIPATE THE GALE GUSTS WILL LAST
LONG OR BE WIDESPREAD. THE SEAS WILL BE CHOPPY AND STEEP MON NIGHT
THROUGH TUE MORNING WHEN THE PRESSURE GRADIENT WILL BE TIGHTEST OVER
THE WATERS. THE WINDS WILL BEGIN TO EASE TUE NIGHT AS A WEAK FRONT
APPROACHES THE REGION AND REMAIN LIGHT UNTIL THE FRONT PUSHES
THROUGH WED NIGHT. W-NW SWELL TRAIN WITH THIS SYSTEM WILL BEGIN TO
BUILD OVER THE REGION MID TO LATE WEDNESDAY. TH
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR WINDS AND HAZARDOUS SEAS FROM CAPE
MENDOCINO TO POINT ARENA OUT 10 TO 60 NM.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
[top]
000
FXUS66 KSTO 212159
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
300 PM PDT SUN SEP 21 2008
.DISCUSSION...
NAM APPEARS TO HAVE BETTER HANDLE ON POSITION OF MULTIPLE SHORT
WAVES THIS AFTERNOON WHEN COMPARED TO WATER VAPOR AND FORECASTS
SEVERAL CHANNELED VORT MAXES TO MOVE ACROSS INTERIOR NORCAL THROUGH
ABOUT 06Z TONIGHT. NAM SHOWING AN AREA OF 300-500 J/KG CAPES
EXTENDING FROM EASTERN SLOPES OF THE COASTAL MOUNTAINS...ACROSS
SHASTA COUNTY INTO THE NORTHEAST PLATEAU. VIS SATELLITE SHOWING SOME
CU IN THESE AREAS AND ALONG WEST SLOPES OF THE SIERRA NEVADA...NORTH
OF I-80. 88-D SHOWING SHOWING AN AREA OF THUNDERSTORM DEVELOPMENT
THIS AFTERNOON OVER SISKIYOU COUNTY. THESE CELLS MOVING MOSTLY DUE
EAST AND SHOULD MISS OUR CWA. ALTHOUGH MOISTURE IS MORE LIMITED
FARTHER SOUTH OVER OUR CWA...WILL KEEP A SLIGHT CHANCE OF AN
ISOLATED SHOWER OR THUNDERSTORM OVER NORTHERN PORTIONS THROUGH
EARLY EVENING.
BEHIND FINAL EXITING SHORT WAVE TONIGHT WEAK RIDGING ALOFT PROGGED
TO MOVE OVER NORCAL FOR THE NEXT SEVERAL DAYS AS SURFACE HIGH
PRESSURE EXTENDS THROUGH OREGON INTO THE GREAT BASIN. THIS MAY SOME
LOCALLY GUSTY NORTH TO NORTHEAST WIND LATE TONIGHT INTO MONDAY
MORNING OVER PORTIONS OF THE NORTHERN INTERIOR MOUNTAINS AND WEST
SLOPES OF THE SIERRA NEVADA. BREEZY CONDITIONS ARE EXPECTED TO
REMAIN VERY LOCALIZED TO FAVORABLY ORIENTED CANYONS AND PASSES THUS
FOREGOING ANY MAJOR FIRE WEATHER CONCERNS. GRADIENT IS FORECAST
WEAKER AFTER MONDAY.
AMS WARMS SOME SYNOPTICALLY THROUGH MIDWEEK AS UPPER RIDGING
GRADUALLY INCREASES OVER THE AREA. 850 MB TEMPS INCREASE ABOUT 2
DEGS C MONDAY INTO TUESDAY AS TEMPERATURES RETURN TO SEASONABLE
NORMALS. SLIGHT ADDITIONAL WARMING INTO WEDNESDAY AS FOUR-CORNERS
HIGH BEGINS TO EXPAND TO THE NORTHWEST.
PCH
.EXTENDED DISCUSSION (WEDNESDAY NIGHT THROUGH SUNDAY)...A LOW
PRESSURE SYSTEM WILL MOVE INTO THE PACIFIC NORTHWEST ON WEDNESDAY
BUT WILL RIDE OVER A HIGH PRESSURE CELL BUILDING IN THE DESERT
SOUTHWEST. ADDITIONAL SHORT WAVES MAY RIDE OVER THE HIGH PRESSURE
THROUGH THE WEEK BUT ANY SHOWERS ASSOCIATED WITH THESE SYSTEMS ARE
EXPECTED TO STAY NORTH OF CALIFORNIA. MAX TEMPS ACROSS THE CWA WILL
FLUCTUATE NEAR TO A FEW DEGREES ABOVE NORMAL UNDER A FAIRLY DRY
AIRMASS. A STRONGER STORM DEVELOPS IN THE GULF OF ALASKA BY THE END
OF THE WEEK BUT ITS TROUGH SHOULD REMAIN OFF THE SHORE OF CALIFORNIA
THROUGH THE WEEKEND. JBB
&&
.AVIATION...
VFR CONDS CONTINUE AS SCATTERED MID TO HIGH LEVEL CLOUDS STREAM
ACROSS THE CWA. CUMULUS BUILDUPS ON SATELLITE ARE EVIDENT OVER
HIGHER TERRAIN WITH THE BEST CONCENTRATION ALONG THE NORTHERN SIERRA
CREST. LIGHT SHOWERS/ISOLATED THUNDERSTORMS MAY AFFECT THE HIGHER
ELEVATIONS OF EASTERNMOST SHASTA COUNTY INCLUDING THE LASSEN PARK
AREA THROUGH 06Z TONIGHT. WINDS UNDER 10 KTS THROUGH TOMORROW FOR
MOST OF THE CWA. THE NORTH-SOUTH GRADIENT FROM MFR-SAC IS STILL
PROGGED TO BE 5-7 MB FROM 06-18Z. THIS WILL ONLY AFFECT THE NORTHERN
SAC VALLEY WITH SFC WINDS AROUND 10 KTS AND MODERATE 15-20 KT WINDS
NEAR 1000-2000 FT AGL. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 212142
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
242 PM PDT SUN SEP 21 2008
.DISCUSSION...THE INFLUENCE OF A COOL AND STABLE AIRMASS OVER
CENTRAL CALIFORNIA CONTINUED TO PROVIDE CLEAR SKIES THIS
AFTERNOON. THE UPPER TROUGH THAT INTRODUCED THE COOLER
CONDITIONS MOVED INTO CANADA TODAY WITH A MORE ZONAL FLOW PATTERN
REMAINING OVER CALIFORNIA. THIS FLOW PATTERN ALLOWED TO LITTLE
CHANGE TODAY WITH TEMPERATURES JUST SLIGHTLY HIGHER THEN THOSE OF
YESTERDAY AFTERNOON. SHORT RANGE MODELS PROG 850MB TEMP TO RISE
BY 1-2 DEG-C ON MONDAY...WHICH SHOULD ALLOW MANY MORE LOCATIONS
TO REACH WELL INTO THE 80S BY AFTERNOON. CONDITIONS WILL REMAIN
DRY AS THE FLOW ALOFT REMAINS IN A GENERALLY ZONAL PATTERN.
BEYOND MONDAY...AN UPPER RIDGE IS STILL EXPECTED TO BUILD IN FROM
THE SOUTHWEST AND INTRODUCE A WARMING TREND BEGINNING EARLY THIS
WEEK. THIS WARMING TREND WILL CONTINUE THROUGH THE END OF THE WEEK
AS THE RIDGE BECOMES THE DOMINATE FEATURE OVER THE WEST. LATEST
MODEL GUIDANCE HAS THE CENTRAL VALLEY WARMING BACK UP INTO THE MID
90S BY MID-WEEK BEFORE ANOTHER COOL DOWN IS INTRODUCED OVER THE
WEEKEND. MODELS SHOW THIS COOL DOWN ASSOCIATED WITH A TROF ENTERING
THE REGION BY THE END OF THE WEEK THAT WILL USHER IN THIS COOL
DOWN OVER THE WEST. THE SYSTEM TOWARD THE END OF THE WEEK WILL
REMAIN DRY WITH NO PRECIP EXPECTED OVER CENTRAL CALIFORNIA.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL
CALIFORNIA INTERIOR THROUGH 00Z TUESDAY.
&&
.AIR QUALITY ISSUES...ON SUNDAY SEPTEMBER 21 2008...
UNHEALTHY FOR SENSITIVE GROUPS IN KERN COUNTY. FURTHER INFORMATION
IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...SANGER
WEATHER.GOV/HANFORD
000
FXUS66 KMTR 212135
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
230 PM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 2:30 PM PDT SUNDAY...WARMER FOR THE MIDDLE PART
OF THIS WEEK.
TEMPERATURES HAVE WARMED UP CLOSE TO WHAT WE HIT YESTERDAY WITH
VIRTUALLY ALL SPOTS IN THE 60S AND 70S. VISIBLE SATELLITE LOOP
SHOWS MOST PLACES NEARLY CLOUD FREE EXCEPT RIGHT AT THE COAST FROM
SAN FRANCISCO TO DOWN TO PEBBLE BEACH WITH A LARGE CLEAR AREA
AROUND SANTA CRUZ. OVERALL THE HIGH RESOLUTION WRF HAS DONE A GOOD
JOB HANDLING CLOUDS ACROSS OUR AREA AND WAS HEAVILY USED FOR THE
CLOUD PORTION OF THE FORECAST. WITH THE NORTHERLY GRADIENT TWICE THE
ONSHORE COMPONENT...MOSTLY CLEAR SKIES SHOULD REMAIN OVER THE
INTERIOR. THE COAST SOUTH OF SANTA CRUZ WILL NOT FARE SO WELL AS THE
FLOW SHOULD KEEP CLOUDS GOING INTO THE OVERNIGHT HOURS. FOR NORTH OF
SANTA CRUZ ALONG THE COAST IT IS A TOUGHER CALL. THE WRF BRINGS
CLOUDS BACK INTO PART OF THE AREA ALTHOUGH IT IS QUITE POSSIBLE THAT
THE FLOW WILL PUSH THE LINE OF CLOUDS SOUTH OF SANTA CRUZ. FOR THE
FORECAST...DECIDED TO GO WITH CLOUDY SKIES OVERNIGHT OVER THE COAST
OF SOUTHERN MONTEREY WITH JUST MOSTLY CLEAR TO PARTLY CLOUDY SKIES
NORTH OF SANTA CRUZ.
OVERALL...THE WEEK IS SHAPING UP TO BE QUIET WITH ALL OF THE MAJOR
MODELS KEEPING THE STORM TRACK WELL TO THE NORTH WHILE A RIDGE
RETURNS TO OUR AREA. TEMPERATURES WILL INCREASE EACH DAY THIS WEEK AT
LEAST THROUGH WEDNESDAY WHICH WILL BRING THEM BACK TO ABOVE NORMAL
READINGS OVER THE INTERIOR PORTIONS IN PARTICULAR. EVEN WITH THE
WARMER WEATHER...TEMPERATURES SHOULD STILL FALL WELL SHORT OF ANY
HEAT RELATED CRITERIA. BEYOND WEDNESDAY THERE IS DISAGREEMENT
AS ONE GROUP KEEPS THE RIDGE OVERHEAD WHILE ANOTHER SHOWS A PACIFIC
TROUGH MOVING IN HELPING TO DISPLACE THE RIDGE. UNTIL A BETTER
CONSENSUS IS REACHED THE TEMPERATURES IN THE GIRDS WERE NOT GREATLY
CHANGED WHICH PRODUCED HIGHS CLOSE TO NORMAL.
&&
.AVIATION...AS OF 10:30 AM PDT SUNDAY...STRATUS HAS CLEARED FROM
THE NORTH BAY BUT WILL PERSIST ANOTHER HOUR OR SO IN THE SAN
FRANCISCO TO OAKLAND AREA AS WELL AS THE MONTEREY BAY. AFTERNOON
ONSHORE GRADIENT WINDS WILL BECOME GUSTS TO AROUND 25 KNOTS IN THE
VICINITY OF KSFO AND DECREASE AROUND SUNSET. WITH INCREASING HIGH
PRESSURE AND A MORE ROBUST NORTHERLY GRADIENT TONIGHT EXPECT LESS
STRATUS IN THE SAN FRANCISCO BAY AREA.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: WJK
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 212115
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 PM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
MOSTLY CLEAR SKIES CAN BE EXPECTED THIS WEEK AS A RIDGE OF HIGH
PRESSURE BECOMES CENTERED OVER THE SOUTHWEST. A FEW DEGREES OF
WARMING CAN BE EXPECTED BY WEDNESDAY WITH TEMPERATURES REMAINING
ABOVE AVERAGE INTO NEXT WEEKEND.
&&
.DISCUSSION...
CONSIDERABLY LESS CLOUDINESS OVER SOUTH-CENTRAL ARIZONA THIS
AFTERNOON THAN YESTERDAY. SURFACE DEW POINTS ARE RUNNING SEVERAL
DEGREES LOWER EARLY THIS AFTERNOON AS COMPARED TO 24 HOURS AGO. ONLY
REAL CUMULUS DEVELOPMENT HAS BEEN OVER ZONE 24 BUT WITH LIMITED
VERTICAL DEVELOPMENT. CONVECTION IS ANTICIPATED TO REMAIN SHALLOW
AND THUS DROPPED THE VERY MODEST POPS WE HAD OVER ZONE 24 FOR THE
AFTERNOON PACKAGE.
AS PREVIOUSLY DISCUSSED...PROGS SHOW A CONTINUED DECLINE IN MOISTURE
FROM WEST TO EAST FOR VERY LITTLE IF ANY CLOUDINESS THE NEX FEW
DAYS. TROUGHS PASSING TO THE NORTH DURING THE NEXT 24-36 HOURS WILL
LEAD TO SOME LOCALIZED BREEZINESS BUT THEY WILL BE TOO FAR NORTH TO
GENERATE MUCH IN THE WAY OF STRONG SURFACE WINDS OVER OUR AREA.
RIDGE BUILDING INTO THE AREA TUESDAY AND WEDNESDAY WILL LEAD TO AT
LEAST A FEW DEGREES OF WARMING MOST PLACES.
DURING THE LATTER HALF OF THE WEEK...PROGS IN GOOD AGREEMENT THAT
THE RIDGE WILL REMAIN CENTERED OVER THE SOUTHERN ROCKIES THROUGH
FRIDAY AS A PACIFIC TROUGH SLOWLY ADVANCES EASTWARD. ANTICIPATE
SLIGHT COOLING OVER NEXT WEEKEND PER GFS AND GFS ENSEMBLE MEAN AS A
SOUTHERN BRANCH TROUGH MOVES INTO THE CALIFORNIA COAST. THIS WOULD
ALSO LEAD TO MORE NOTICEABLE AFTERNOON AND EVENING BREEZES.
&&
.AVIATION...
WINDS ALOFT INVOF PHOENIX EXPECTED TO REMAIN SOUTHWEST...AND WITH
SOME MIXING THRU 10 THSD FT...POSSIBLE GUSTY WINDS STILL EXPECTED
LATE THIS AFTERNOON AND INTO EARLY EVENING. MOISTURE IS STILL
SUFFICIENT BLO THE INVERSION...AND FEW FLAT CU WILL FORM MAINLY
OVER THE HIGHER TERRAIN INVOF KPHX/KIWA WITH CLEARING THIS EVENING.
NO CONCERNS FOR THE WESTERN TAF SITES THRU AT LEAST 12Z MONDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...SIPPLE
FIRE WEATHER...SIPPLE
000
FXUS66 KLOX 212104
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PDT SUN SEP 21 2008
.SHORT TERM (TODAY-WEDNESDAY)...
MOST OF THE AREA RUNNING A BIT COOLER THAN YESTERDAY THANKS TO A
SLIGHTLY INCREASED MARINE INFLUENCE. THE MOUNTAINS AND DESERTS
HOWEVER ARE SEEING WARMER TEMPS THANKS TO THE STRONGER INVERSION AND
THE PASSAGE OF THE COLD AIR ALOFT THAT MOVED IN YESTERDAY. STRATUS
HAS CLEARED FOR THE MOST PART THIS AFTERNOON...BUT IT LOOKS PRIMED
FOR ANOTHER REPEAT TOMORROW...AS ANOTHER EDDY FORMS SOUTH OF POINT
CONCEPTION AND LITTLE CHANGE EXPECTED TO THE NORTH.
WIND-WISE...ONLY CONCERN IS FOR ONE MORE ROUND OF GUSTY BUT
SUB-ADVISORY NORTHERLY FLOW THROUGH THE I5 CORRIDOR TONIGHT. LOOKS
LIKE ONE MORE ROUND OF FALL-LIKE CHILLY OVERNIGHT LOW TEMPS
TONIGHT...BUT THOSE TEMPS SHOULD INCREASE AFTER TONIGHT AS THE
AIRMASS BEGINS TO WARM UP.
THE WARMING TREND STILL LOOKS GOOD MON THRU WED. 12Z GFS STILL
SLOWLY BUILDS A HEALTHY 590 DM RIDGE UP FROM THE SOUTH THROUGH THIS
PERIOD. FOR LAST FEW DAYS...THE MODELS HAVE BEEN ADVERTISING A WEAK
LOW OFF TO OUR WEST...BUT THE 00Z AND 12Z RUNS HAVE WEAKENED THIS
LOW EVEN MORE...ALLOWING THE HIGH TO BUILD FURTHER WESTWARD.
ALTHOUGH THIS SOLUTION WILL LIKELY GO THROUGH A FEW MORE CHANGES
OVER THE NEXT RUNS...THE PICTURE IS SHAPING UP WELL FOR THE TIMING
AND GENERAL MAGNITUDE OF THE WARMING TREND. ADDING TO THE WARMING IS
A GRADUAL WEAKENING OF THE ONSHORE GRADS. IN FACT...THE NAM SHOWS A
0.0MB LAX-DAG GRAD WED MORNING. THIS IS DUE TO SOME WEAK HIGH
PRESSURE OVER COLORADO AND THE WARM TEMPS TO THE NORTH INDUCING AN
INVERTED SURFACE TROUGH ALONG THE CA COAST. ALL THIS POINTS TO A
RATHER WARM WED AND FORECAST WAS ADJUSTED UP A FEW DEGREES IN MOST
PLACES...ESPECIALLY THE LA/VTU VALLEYS. WED COULD BE EVEN WARMER IF
THE HIGH BUILDS FURTHER WEST...AND ONSHORE GRADS DO NOT QUICKLY
SWING BACK ONSHORE IN THE AFT AS THE NAM IS TRYING TO SHOW. THE
MARINE LAYER WILL GRADUALLY SQUASH DOWN WITH HEIGHTS BUILDING AND
THE EDDY DYING AFTER MON. KEPT STRATUS ALONG ALL THE IMMEDIATE
COASTAL SPOTS BY TUE...BUT LIKELY REALITY IS THAT EVEN SOME COASTAL
SPOTS WILL STAY STRATUS FREE.
.LONG TERM (THURSDAY-SUNDAY)...
MODELS HAVE BEEN FLIP FLOPPING A BIT FOR THU AND FRI. A TROUGH
SHOULD DIG DOWN FROM ALASKA AND PUSH OUR WARM RIDGE EASTWARD...BUT
WHETHER THAT HAPPENS THU NIGHT LIKE THE 0Z RUNS SUGGESTED OR FRI
NIGHT LIKE THE 12Z RUNS IS LEFT TO BE SEEN. THE 12Z RUNS ACTUALLY
WEAKEN THE ORIGINAL TROUGH...WHILE A RATHER LARGE TROUGH JUST SOUTH
OF ALASKA STEALS SOME OF ITS ENERGY. THIS NEW SOLUTION RESULTS IN
SHIFTING THE HIGH ONLY SLIGHTLY TO THE EAST...AND KEEPING US FAIRLY
WARM FRI THROUGH SUN. NOT ONLY THAT...BUT THIS PATTERN PUTS THE HIGH
INTO A FAVORABLE SOUTHERLY FLOW REGIME FOR OUR AREA...WHICH COULD
PULL UP ANY AVAILABLE MOISTURE FROM MEXICO. DID NOT BITE ON THIS
JUST YET...SINCE THIS MOISTURE WOULD NOT GET HERE UNTIL FRIDAY...BUT
IF THE MODELS CONTINUE TO SING THE SAME TUNE THROUGH THIS WEEK...IT
WILL BE TOUGH TO IGNORE FOR LONG. EITHER WAY...FRI THROUGH SUN
SHOULD BE A BIT COOLER...BUT UNTIL WERE SEE MORE STABILITY IN THE
SOLUTIONS...DID NOT GET TOO CUTE AND JUST TRENDED TEMPS DOWN A BIT
EACH DAY BACK TOWARD NORMAL.
&&
.AVIATION...21/1800Z.
AN UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC WILL
SHIFT EAST WHILE A BROAD TROUGH OF LOW PRESSURE OVER THE AREA SHIFTS
OVER THE GREAT BASIN. MODERATE UPPER LEVEL WEST FLOW WILL BECOME
MODERATE NORTHWEST THROUGH THE PERIOD. A WEAK INVERSION CAPPING A
UNORGANIZED MARINE LAYER THIS MORNING WILL STRENGTHEN AND DESCEND
OVERNIGHT. LOW CLOUD TOPS VARIED FROM 1.8KFT OVER SANTA MONICA BAY
TO 2.6KFT OVER SAN GABRIEL VALLEY AND WILL CONTINUE TO CLEAR INLAND
AND LINGER OVER THE BIGHT THROUGH THE EARLY PERIOD. A CATALINA EDDY
WILL LIKELY REDEVELOP AND LOW CLOUDS WILL RETURN TO THE VALLEYS
OVERNIGHT.
KLAX...THERE IS A CHANCE CIGS 020-025 WILL LINGER THROUGH NOON. IT
IS VERY LIKELY CIGS 012-015 WILL RETURN IN THE LATE EVENING AND
PREVAIL THROUGH THE REMAINDER OF THE PERIOD.
KBUR...IT IS LIKELY CIGS 015 WILL REDEVELOP AROUND SUNRISE.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL
AVIATION...30
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSGX 212041
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT SUN SEP 21 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. WEAK UPPER LEVEL LOW PRESSURE WILL KEEP MOST TEMPERATURES
BELOW SEASONAL AVERAGES THROUGH MONDAY. BREEZY IN THE MOUNTAINS AND
DESERTS AT TIMES. WARMER DURING THE SECOND HALF OF THE WEEK UNDER
HIGH PRESSURE THEN COOLER AGAIN TOWARD NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (THIS AFTERNOON THROUGH WEDNESDAY)...
STRATUS WAS SLOW TO CLEAR IN A FEW AREAS THIS MORNING DUE TO A
COASTAL EDDY. TEMPS ACROSS THE FORECAST AREA ARE RUNNING SLIGHTLY
COOLER THAN 24 HOURS AGO...EXCEPT IN THE MOUNTAINS WHERE TEMPS HAVE
INCREASED SOME. HIGH TEMPS ARE STILL ON TRACK TO BE 5-10 DEGREES
BELOW SEASONAL AVERAGES. ONSHORE PRESSURE GRADIENTS WITH ABOUT 7 MB
SAN-TRM AND 5 MB SAN-DAG...AND THIS WILL CONTINUE LOCALLY BREEZY
CONDITIONS IN THE MOUNTAINS AND DESERTS THIS AFTERNOON AND EVENING.
A TROUGH OF LOW PRESSURE OVER THE WESTERN STATES WILL KEEP TEMPS
BELOW SEASONAL AVERAGES WITH CONTINUING NIGHT AND MORNING LOW CLOUDS
AND FOG MONDAY. DRY AIR ABOVE THE MARINE LAYER SHOULD RESULT IN
ANOTHER CHILLY MORNING IN THE MOUNTAIN VALLEYS AND FOOTHILLS. A
COASTAL EDDY WILL MAINTAIN A 2000 FT DEEP MARINE LAYER WITH LOW
CLOUDS EXTENDING WELL INLAND.
HIGH PRESSURE BUILDING OVER THE SOUTHWEST WILL CAUSE HEIGHTS AND
THICKNESS VALUES TO INCREASE ACROSS THE FORECAST AREA TUESDAY AND
WEDNESDAY. THIS WILL CAUSE TEMPS TO WARM BACK TO SEASONAL AVERAGES
ON TUESDAY...AND ABOVE SEASONAL AVERAGES ON WEDNESDAY. THE MARINE
LAYER INVERSION WILL LOWER TO AROUND 1000 FT OR LESS AND STRATUS
WILL PROBABLY BE CONFINED TO THE COAST AND WESTERN VALLEYS. NEUTRAL
TO WEAK OFFSHORE PRESSURE GRADIENTS FROM THE NORTH MAY PREVENT
STRATUS FROM SPREADING INTO INLAND ORANGE COUNTY.
&&
.LONG TERM (THURSDAY THROUGH SUNDAY)...
HIGH PRESSURE WILL LINGER OVER THE SOUTHWEST ON THURSDAY AND WILL
MAINTAIN HIGHER THAN AVERAGE TEMPS AND A SHALLOWER MARINE LAYER.
LIMITED MID LEVEL MOISTURE IN SOUTH FLOW ALOFT MAY ALSO BRING SOME
AFTERNOON CLOUDS TO THE MOUNTAINS...BUT NO THUNDERSTORMS.
FOR FRIDAY THROUGH SUNDAY...HIGH PRESSURE WILL SHIFT TO THE EAST AS
A WEAK TROUGH OF LOW PRESSURE DEVELOPS OFF THE WEST COAST. THIS WILL
BRING COOLER WEATHER AND A DEEPER MARINE LAYER WITH INCREASING LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS.
&&
.AVIATION...
212000Z...MARINE LAYER STRATUS HAS ERODED EXCEPT FOR A LARGE AREA
SPIRALING AROUND THE EDDY CENTERED OVER SAN NICOLAS ISLAND. EXPECT
EDDY TO CONTINUE AND TO START PUSHING THE STRATUS BACK INLAND AFTER
SUNSET WITH BASE 1800 AND TOP 2300 FT MSL. STRATUS AND AREAS OF 3
SM FOG SHOULD REACH THE VALLEYS AFTER MIDNIGHT. EXPECT MARINE LAYER
CLEARING BY 17Z MONDAY. CLEAR ABOVE THE MARINE LAYER TODAY THROUGH
MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...SCV
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS65 KREV 211953
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
100 PM PDT SUN SEP 21 2008
.SHORT TERM...
PRIMARY ISSUE FOR TODAY WAS GAGING THE IMPACT OF APPROACHING UPPER
LEVEL TROF AND JET STREAK, CLEARLY EVIDENT IN THE WATER VAPOR MOVING
INTO NW CA AS OF 18Z. WHAT`S REALLY INTERESTING IS THAT THE JET CORE
SHOWS UP WELL IN THE 250MB GEFS WIND ANOMALY FIELDS (~2SD ABOVE
NORMAL FOR THE ZONAL COMPONENT). BOTH THE GFS AND NAM SHOW STRONG
LIFT ASSOC WITH AMPLIFYING WAVE AND LEFT EXIT REGION OF JET
STREAK...AFFECTING NORTHERN 1/3 OF OUR CWA TONIGHT. THE 9Z SREF
BULKED UP ON QPF ASSOC WITH TROF TONIGHT COMPARED TO 3Z RUN. TO
CONTRAST THAT, LOCAL WRF USING THE NAM BOUNDARY CONDS IS
SURPRISINGLY DRY.
AM FIGURING WITH THE STRONG DYNAMICS, THAT WILL OVERCOME ANY LACK OF
INSTABILITY AND LOW LVL MOISTURE TO PRODUCE ISOLD-SCT SHRA LATE THIS
AFTERNOON THROUGH MIDNIGHT ROUGHLY NORTH OF A SVE-LOL LINE. WILL
RETAIN CHC OF THUNDER, GIVEN STRONG DYNAMICS AND COOLING TEMPS ALOFT
(MORE GRAUPEL/CHARGED PARTICLES...A COUPLE CC`S OR CG`S ARE
POSSIBLE). BASED ON SOUNDING WET BULB PROFILES, SNOW LEVELS WILL
DROP BELOW 8KFT TONIGHT UP NORTH, AND THOUGH NOT IN OUR CWA SOME
LIGHT SN POSSIBLE IN WARNERS OF NE CA.
WINDS ALOFT WILL REMAIN STRONG THROUGH MONDAY MORNING AS UPPER JET
TRACKS OVER THE REGION. GEFS 700MB WIND ANOMALIES ARE CLOSE TO 1 SD
ABOVE NORMAL THROUGH THIS EVENING. EXTREMELY DRY AIR ALOFT FORECAST
TO ADVECT INTO THE SIERRA LATE TONIGHT. THIS AIR WILL EVENTUALLY MIX
DOWNWARD MON AFTN INTO MON NIGHT, SUCH THAT RH RECOVERIES TUES
MORNING WILL LIKELY BE POOR FOR MANY AREAS. THIS EVEN SHOWS UP IN
THE NAEFS METEOGRAM AT RNO!
INTO MID-WEEK, FLOW ALOFT WILL BECOME MORE ZONAL WITH INCREASING
HEIGHTS. A GRADUAL WARMING TREND IS EXPECTED AS A RESULT. LOW
CURRENTLY EXHIBITING A NICE BAROCLINIC LEAF SIGNATURE BETWEEN 150
AND 160W IS FORECAST BY GEFS AND ECMWF TO MOVE NEAR THE PAC NW/BC ON
WED. PRECIP ASSOC WITH THAT SYSTEM WILL REMAIN WELL N OF THE CWA,
HOWEVER 700MB WIND FIELDS IN GEFS DO INDICATE AT LEAST AN INCREASE
IN WIND FOR WED.
CS
.LONG TERM...THURSDAY THROUGH SUNDAY...
QUIET WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE
EXTENDED. THE MEDIUM RANGE MODELS CONTINUE TO SHOW A SYSTEM MOVING
TOWARD THE WEST COAST ON THURSDAY. THE GFS FORMS A DEEPER TROUGH
THAN DOES THE ECMWF AND THIS WOULD AFFECT HOW MUCH SLY FLOW AND
MOISTURE ADVECTION WE WOULD SEE AHEAD OF THE SYSTEM. ON FRIDAY THE
GFS IS MORE AGGRESSIVE IN DIGGING THIS UPPER TROUGH SOUTH TO AROUND
30N 130W. THE ECMWF KEEPS A MORE ZONAL FLOW ACROSS THE WEST COAST
WITH THE SWRN RIDGE EXTENDING WEST INTO THE ERN PACIFIC. BECAUSE OF
THIS UNCERTAINTY IN THE MODEL SOLUTIONS HAVE DECIDED TO KEEP FRIDAY
DRY FOR NOW. HOWEVER DID INCREASE CLOUD COVER SOME BUT KEPT POPS
BELOW 10 PERCENT. THESE ELEMENTS CAN BE ADJUSTED UPWARD IF THE
MODEL SOLUTIONS START TO CONVERGE TOWARD A WET PATTERN.
AS THIS FIRST WEAK TROUGH PUSHES TO THE EAST LATE IN THE WEEK BOTH
THE GFS AND THE EURO SHOW A DEEPENING UPPER TROUGH MOVING INTO THE
GULF OF ALASKA ON SATURDAY AND THEN DIGGING SOUTH ON SUNDAY. THIS
COULD BECOME A SIGNIFICANT SYSTEM AND WOULD AFFECT THE KREV CWFA
EARLY NEXT WEEK SO ITS EVOLUTION WILL CONTINUE TO BE WATCHED. O`HARA
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH MONDAY. GUSTY WINDS EXPECTED
THIS AFTN AND EVENING WITH GUSTS TO 30 KTS POSSIBLE. ISOLD TSRA
ALSO POSSIBLE THIS EVENING ACROSS FAR NWRN NEVADA AND FAR NERN
CALIFORNIA MAINLY THROUGH 06Z. O`HARA
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS65 KPSR 211942 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1240 PM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UDPATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN TODAY. OTHERWISE
...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT SOUTHWEST
THE NEXT COUPLE DAYS...AS AN AREA OF LOW PRESSURE PASSES TO THE
NORTH. DRY CONDITIONS WILL CONTINUE THIS WEEK...UNDER MOSTLY CLEAR
SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
12Z SOUNDINGS LOOK A BIT LESS FAVORABLE FOR DEVELOPMENT OF ISOLATED
STORMS THAN EVEN YESTERDAY. HOWEVER...MOISTURE IS STILL AROUND OVER
SOUTH-CENTRAL ARIZONA PER RAOBS AND PLOT DATA. DRYING OVER WESTERN
PORTIONS OF THE FORECAST AREA QUITE EVIDENT IN THE DEW POINT TRENDS.
WITH THE LOWER DEW POINTS...MIN TEMPS DIPPED DOWN QUITE NICELY WITH
SOME LOWER DESERT LOCATIONS IN THE IMPERIAL VALLEY DROPPING INTO THE
LOW 60S. WATER VAPOR IMAGERY SHOWS ZONAL FLOW ALOFT OVER SOUTHERN
CALIFORNIA AND ARIZONA WITH A LOW MOVING INTO NORTHERN CALIFORNIA
AND THE PACIFIC NORTHWEST...AND ANOTHER ONE JUST UPSTREAM OF IT.
LATEST PROGS SHOW LOWER LEVEL MOISTURE LINGERING OVER SOUTH-CENTRAL
ARIZONA TODAY WITH A FAIRLY SHARP GRADIENT OVER SOUTHWEST ARIZONA
AND WESTERN MARICOPA COUNTY. WARM LAYER ROUGHLY BETWEEN 600-700 MB
WILL LIMIT DEPTH OF CONVECTION TODAY. HOWEVER...JUST ENOUGH MOISTURE
TO CARRY SMALL AREA OF SLIGHT CHANCE POPS IN ZONE 24...FOR NOW.
REGARDING TEMEPRATURES...COOL START OUT WEST MAY LEAD TO SLIGHTLY
LOWER MAX TEMPS FOR TODAY...BUT DRIER AIR WILL ENABLE LARGER DIURNAL
RANGE WHICH SHOULD OFFSET THE COOLER START. JUST SOME MINOR WIND AND
DEW POINT UPDATES IN THE GRIDS THIS MORNING.
PROGS CONTINUE TO SHOW EVEN LESS MOISTURE AVAILABLE MONDAY AS THE
LOWS CURRENTLY WELL TO OUR NORTHWEST MOVE THROUGH THE INTERIOR WEST.
SYSTEMS WILL PASS FAR ENOUGH TO OUR NORTH THAT THERE WILL BE LITTLE
EFFECT ON OUR AREA. BEHIND THE TROUGH...THE RIDGE CENTERED OVER
MEXICO WILL EXPAND NORTHWARD ON TUESDAY THOUGH THERE WONT BE A BIG
CHANGE IN HEIGHTS AND THICKNESSES. THUS LITTLE CHANGE IN TEMPS.
PREVIOUS DISCUSSION...
SAT IMAGERY EARLY THIS MORNING SHOWS MOSTLY CLEAR/CLEAR SKIES OVER
SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA. 24 HR
CHANGE PRODUCT INDICATES SFC DEW POINTS FROM THE CO RIVER WESTWARD
ARE RUNNING 15-20 DEG LOWER THAN THIS TIME YESTERDAY. THE DRIER
CONDITIONS AND CLEAR SKIES WILL ALLOW FOR MAXIMUM RADIATIONAL
COOLING OVERNIGHT...WITH THIS MORNING/S LOWS OUT WEST RUNNING 4-7
DEG COOLER THAN SATURDAY MORNING. NOT AS MUCH DRYING OVER THE LOWER
SOUTH-CENTRAL ARIZONA DESERTS...AND CURRENT IR SAT TRENDS EVEN SHOW
A FEW LOW LEVEL CLOUDS OVER PORTIONS OF NORTHWESTERN PINAL AND
SOUTHERN GILA COUNTY. THE KSPR 00 UTC SUN SOUNDING FROM EARLIER
INDICATES AN INCREASE IN MOISTURE (OVER 24 HOURS AGO) WITH A FAIRLY
MOIST LAYER BETWEEN 800-750MB (AROUND 8K-15K FT). WITH THE LINGERING
MID LEVEL MOISTURE IN PLACE...THE INHERITED SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN EAST OF
PHOENIX...OVER PORTIONS OF SOUTHERN GILA COUNTY...FOR THIS
AFTERNOON/EARLY EVENING LOOKS GOOD. ELSEWHERE...A DRY FORECAST
REMAIN IN PLACE. AS FOR TEMPS...THE FLAT RIDGE (IN RESPONSE TO THE
TROUGH MOVING BY WELL TO THE NORTH) WILL RESULT IN LITTLE CHANGE IN
HIGH TEMPS TODAY WITH THE WARMEST DESERT LOCALES AROUND 100 DEG.
MONDAY THROUGH THE REST OF THE WEEK...THE MORE POTENT LOW MOVING
THROUGH THE PAC NW/NRN ROCKIES THIS WEEKEND WILL GIVE WAY TO A BROAD
TROUGH OVER MUCH OF THE WESTERN CONUS MON/TUES. AS IT DOES SO...THE
LARGE ANTI-CYCLONE (PROGGED BY THE MODELS FOR THE PAST SEVERAL RUNS)
WILL BUILD OVER THE GREATER SOUTHWEST. EVEN WITH THE HIGH IN PLACE
THE MID TO LATTER PART OF THE WEEK...MODELS ARE NOT INDICATING MUCH
OF AN INCREASE IN THICKNESS/500MB HEIGHTS...SO DO NOT EXPECT MUCH
DAY TO DAY CHANGE IN TEMPS. MEANWHILE...SKIES WILL REMAIN MOSTLY
CLEAR...WITH A FEW AFTERNOON CU POSSIBLE OVER THE HIGHER TERRAIN TO
THE EAST. WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS...WITH WESTERLY
BREEZES/GUSTS AROUND 15-20 MPH AT TIMES DURING PEAK HEATING EACH DAY
THIS UPCOMING WEEK.
&&
.AVIATION...
WINDS ALOFT INVOF PHOENIX EXPECTED TO REMAIN SOUTHWEST...AND WITH
SOME MIXING THRU 10 THSD FT...POSSIBLE GUSTY WINDS STILL EXPECTED
LATE THIS AFTERNOON AND INTO EARLY EVENING. MOISTURE IS STILL
SUFFICIENT BLO THE INVERSION...AND FEW FLAT CU WILL FORM MAINLY
OVER THE HIGHER TERRAIN INVOF KPHX/KIWA WITH CLEARING THIS EVENING.
NO CONCERNS FOR THE WESTERN TAF SITES THRU AT LEAST 12Z MONDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...SIPPLE
FIRE WEATHER...SIPPLE
000
FXUS66 KLOX 211746
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 AM PDT SUN SEP 21 2008
UPDATED AVIATION SECTION
.SHORT TERM (TODAY-WEDNESDAY)...
MARINE LAYER A BIT ERRATIC THIS MORNING...WITH DEPTHS RANGING FROM
1000 TO 2200 FT AND STRATUS COVERING MORE LAND THAN OCEAN. A DECENT
EDDY FORMED SOUTH OF POINT CONCEPTION...WHICH IS CONTINUING TO HELP
PUSH THE CLOUDS DEEP INTO THE VALLEYS. THE MARINE INVERSION ITSELF
REMAINS RATHER WEAK EVERYWHERE...AND FULL CLEARING EXPECTED BY NOON
AT THE LATEST. MORNING LOWS WERE ONCE AGAIN CHILLY...ESPECIALLY
WHERE THE CLOUDS AND WINDS STAYED OUT. SPEAKING OF WINDS...GUSTY
NORTHERLY FLOW UP TO 40 MPH MATERIALIZED THROUGH THE I5 CORRIDOR AND
IS SLOWLY WEAKENING THIS MORNING. SBA SUNDOWNER WINDS HOWEVER DID
NOT DO MUCH AS THE SBA-SMX GRAD NEVER DIPPED BELOW -3MB. SOME
NORTHEAST FLOW HAS FORMED OVER SLO AND SBA CO...BUT IS STRUGGLING TO
WORK ITS WAY DOWN TO THE COAST AS THE STRONGER MARINE INVERSION IS
WINNING THE BATTLE THUS FAR. IF THESE WINDS DO WORK THEIR WAY
DOWN...THE WARM FORECASTED TEMPS FOR THE CENTRAL COAST AND SANTA
YNEZ VALLEY SHOULD MATERIALIZE...BUT IF THEY DO NOT TEMPS WILL BE
MUCH COOLER. LEFT TEMPS AS IS FOR NOW IN HOPE OF A LATE MORNING PUSH
ONCE THE CAP WEAKENS...BUT MAY NEED TO PULL TEMPS DOWN IF THIS DOES
NOT HAPPEN IN THE NEXT HOUR OR SO. REST OF FORECAST LOOKS GOOD WITH
COOLER LA/VTU VLY TEMPS FROM YESTERDAY AND MOSTLY SIMILAR ELSEWHERE.
...FROM PREVIOUS DISCUSSION...
GOOD AGREEMENT BETWEEN BOTH NAM AND GFS SOLUTIONS IN INDICATING
LITTLE CHANGE IN THE MARINE LAYER FOR TONIGHT AND MONDAY.
1000-500 MB THICKNESSES STAY ABOUT THE SAME IN BOTH MODELS. AREAL
COVERAGES SHOULD BE SIMILAR WITH MAYBE SLIGHT THICKENING IN THE
MARINE LAYER SOUTH OF POINT CONCEPTION. THIS WILL BE DUE TO AN
EDDY CIRCULATION OVER THE INNER WATERS.
TEMPERATURES COULD BE MIXED FOR MONDAY. 950 MB TEMPERATURES
WARM OVER THE AREA...BUT THICKNESSES STAY AROUND THE SAME.
SURFACE GRADIENTS TREND MORE ONSHORE SOUTH OF POINT CONCEPTION
AND TREND OFFSHORE NORTH OF POINT CONCEPTION. WITH WARMER SEA
SURFACE TEMPERATURES IN PLACE OVER THE INNER WATERS AND AT THE
BEACHES...FORECAST TRENDS SLIGHT WARMER...BUT A WELL-DEVELOPED
EDDY CIRCULATION COULD PUT THE DAMPER ON THE TREND.
1000-500 MB THICKNESSES AND 950 MB TEMPERATURES TREND UPWARD FOR
MIDWEEK WITH NEUTRAL TO OFFSHORE TRENDING SURFACE GRADIENTS.
MARINE LAYER WILL REMAIN OVER THE COASTAL SECTION...BUT A
DECREASING INFLUENCE IN COVERAGE AND DEPTH WILL LIKELY BRING
WARMER TEMPERATURES TO THE AREA FOR MIDWEEK.
.LONG TERM (THURSDAY-SATURDAY)...SOUTH TO SOUTHWEST FLOW ALOFT
WILL LIKELY REDEVELOP FOR LATE WEEK BRINGING AN INCREASE IN
MARINE LAYER MOISTURE. GFS SOLUTIONS COULD DEVELOP A EDDY
CIRCULATION OVER THE INNER WATERS WITH SOME LOCAL DRIZZLE
POSSIBLE...BUT ECMWF SOLUTIONS DOWNPLAY THE SCENARIO. AT THE VERY
LEAST...A COOLING TREND SHOULD DEVELOP FOR LATE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...21/1800Z.
AN UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC WILL
SHIFT EAST WHILE A BROAD TROUGH OF LOW PRESSURE OVER THE AREA SHIFTS
OVER THE GREAT BASIN. MODERATE UPPER LEVEL WEST FLOW WILL BECOME
MODERATE NORTHWEST THROUGH THE PERIOD. A WEAK INVERSION CAPPING A
UNORGANIZED MARINE LAYER THIS MORNING WILL STRENGTHEN AND DESCEND
OVERNIGHT. LOW CLOUD TOPS VARIED FROM 1.8KFT OVER SANTA MONICA BAY
TO 2.6KFT OVER SAN GABRIEL VALLEY AND WILL CONTINUE TO CLEAR INLAND
AND LINGER OVER THE BIGHT THROUGH THE EARLY PERIOD. A CATALINA EDDY
WILL LIKELY REDEVELOP AND LOW CLOUDS WILL RETURN TO THE VALLEYS
OVERNIGHT.
KLAX...THERE IS A CHANCE CIGS 020-025 WILL LINGER THROUGH NOON. IT
IS VERY LIKELY CIGS 012-015 WILL RETURN IN THE LATE EVENING AND
PREVAIL THROUGH THE REMAINDER OF THE PERIOD.
KBUR...IT IS LIKELY CIGS 015 WILL REDEVELOP AROUND SUNRISE.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL/HALL
AVIATION...30
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KREV 211745 AAB
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
1045 AM PDT SUN SEP 21 2008
.UPDATE...
DON`T PLAN TO DO A LATE MORNING UPDATE, HOWEVER WE WILL BE
INCREASING POPS FOR THIS EVENING IN THE FAR NRN ZONES WITH THE
AFTERNOON FORECAST. MODELS TRENDING STRONGER WITH TROF
AMPLIFICATION. MORE ON THAT LATER. BASED ON LATEST WRF AND MOS
GUIDANCE, WINDS WILL GET A LITTLE GUSTY THIS AFTN...ON THE ORDER OF
25-30 MPH IN THE WRN NV VALLEYS. WINDS ON SIERRA RIDGES WILL REMAIN
STRONG THROUGH TONIGHT AS JET STREAK DROPS SOUTH. SLIDE MTN HAS BEEN
SLOW TO RESPOND, BUT WE EXPECT WINDS THERE TO INCREASE THIS AFTN.
CS
&&
.SHORT TERM...
A WEAK SHORTWAVE TROUGH SEEN ON WATER VAPOR IMAGERY THIS
MORNING...IS APPROACHING THE NORTHERN CALIFORNIA COAST. THIS WAVE
WILL NOT HAVE VERY MUCH MOISTURE ASSOCIATED WITH IT...ALTHOUGH WITH
A FAVORABLE REGION OF THE UPPER LEVEL JET MOVING IN OVERHEAD THERE
REMAINS A SLIGHT CHANCE FOR A THUNDER SHOWER NORTH OF SUSANVILLE AND
GERLACH THIS EVENING. ANY SHOWERS THAT DO DEVELOP WILL MOVE EAST
INTO NORTHERN PERSHING COUNTY BEFORE MIDNIGHT. WINDS WILL INCREASE
IN THE AFTERNOON OUT OF THE WEST WITH GUSTS UP TO 25 TO 30 MPH.
AFTER THIS SHORTWAVE DEPARTS THE AREA...ZONAL FLOW WILL RETURN TO
THE AREA. WE SHOULD SEE AN INCREASE OF HEIGHTS AND TEMPERATURES
ALOFT...WITH SOME AFTERNOON WESTERLIES AND VALLEY TEMPS WARMING UP
SEVERAL DEGREES EACH DAY MON-TUES. HOON
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
FEW CHANGES MADE TO A PRECIPITATION-FREE FORECAST FOR THE EXTENDED
PERIOD. RIDGE OVER THE SOUTHWEST CONUS KEEPS SHORT WAVE ENERGY AND
ASSOCIATED MOISTURE AND PRECIPITATION NORTH OF NEVADA ON WEDNESDAY.
A STRONGER TROUGH APPROACHES THE WEST COAST BY FRIDAY...INITIALLY
DRAWING MID LEVEL MOISTURE INTO SOUTHERN AND EASTERN ZONES. WILL ADD
PARTLY CLOUDY SKIES TO MONO AND MINERAL COUNTIES ON FRIDAY BEFORE A
STRONGER SOUTHWEST FLOW PUSHES THAT MOISTURE EAST OF THE AREA ON
SATURDAY. TEMPERATURES REMAIN ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH 12Z MONDAY. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KMTR 211741
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1040 AM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 9:15 AM PDT SUNDAY...QUIET WEATHER EXPECTED FOR
THE ENTIRE WEEK.
TRICKY TEMPERATURE AND SKY FORECAST FOR TODAY AS THE FORT ORD
PROFILER INDICATES THAT THE MARINE LAYER IS STILL NEXT TO NOTHING
WHILE THE SURFACE PRESSURE GRADIENTS SHOW ONLY A LIGHT ONSHORE FLOW
WHILE THE NORTHERLY COMPONENT IS NEARLY 3 TIMES LARGER. THESE FACTORS
WOULD USUALLY CREATE A FAIRLY FAST BURN-OFF TODAY AND ALLOW
TEMPERATURES TO WARM AT LEAST TO WHAT WE HIT YESTERDAY. HOWEVER THE
24 HOUR CHANGE PRODUCT DOES SHOW A LOT OF PLACES 3 TO 6 DEGREES
COOLER THAN WHAT THEY WERE YESTERDAY WHILE THE HIGH RESOLUTION WRF
MODEL KEEPS CLOUDS AROUND SOUTHERN MONTEREY BAY ALL DAY TODAY AND
DOES NOW SHOW A BURN-OFF FOR OTHER AREAS UNTIL AROUND NOON.
THEREFORE...WILL MONITOR TEMPERATURES OVER THE NEXT COUPLE OF HOURS
AND IF THEY ARE STILL TRENDING COOLER THAN YESTERDAY HIGHS FOR TODAY
WILL BE BUMPED DOWN. CLOUDS MAY ALSO BE INCREASED IF THE WRF STILL
LOOKS LIKE IT HAS A GOOD HANDLE ON THE SITUATION.
PAST THIS AFTERNOON...A TROUGH WILL MOVE ACROSS NORTHERN CALIFORNIA
THIS EVENING AND SHOULD HAVE VIRTUALLY NO IMPACT ON OUR WEATHER.
BEHIND IT A FLAT RIDGE IN ASSOCIATION WITH WARMING ALOFT WILL HELP
TO INCREASE TEMPERATURES AT LEAST THROUGH WEDNESDAY. HIGHS WILL
WARM BACK INTO THE 80S AND 90S FOR MOST INTERIOR LOCATIONS WITH NO
CHANCE OF RAINFALL FORECAST. HOW LONG THE RIDGE STAYS WITH US IS
THE OTHER BIG CHALLENGE FOR THE FORECAST. THAT WILL BE THE MAIN AREA
OF CONCERN FOR THE AFTERNOON PACKAGE.
&&
.AVIATION...AS OF 10:30 AM PDT SUNDAY...STRATUS HAS CLEARED FROM
THE NORTH BAY BUT WILL PERSIST ANOTHER HOUR OR SO IN THE SAN
FRANCISCO TO OAKLAND AREA AS WELL AS THE MONTEREY BAY. AFTERNOON
ONSHORE GRADIENT WINDS WILL BECOME GUSTS TO AROUND 25 KNOTS IN THE
VICINITY OF KSFO AND DECREASE AROUND SUNSET. WITH INCREASING HIGH
PRESSURE AND A MORE ROBUST NORTHERLY GRADIENT TONIGHT EXPECT LESS
STRATUS IN THE SAN FRANCISCO BAY AREA.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: WJK
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 211700
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 AM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN TODAY. OTHERWISE
...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT SOUTHWEST
THE NEXT COUPLE DAYS...AS AN AREA OF LOW PRESSURE PASSES TO THE
NORTH. DRY CONDITIONS WILL CONTINUE THIS WEEK...UNDER MOSTLY CLEAR
SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
12Z SOUNDINGS LOOK A BIT LESS FAVORABLE FOR DEVELOPMENT OF ISOLATED
STORMS THAN EVEN YESTERDAY. HOWEVER...MOISTURE IS STILL AROUND OVER
SOUTH-CENTRAL ARIZONA PER RAOBS AND PLOT DATA. DRYING OVER WESTERN
PORTIONS OF THE FORECAST AREA QUITE EVIDENT IN THE DEW POINT TRENDS.
WITH THE LOWER DEW POINTS...MIN TEMPS DIPPED DOWN QUITE NICELY WITH
SOME LOWER DESERT LOCATIONS IN THE IMPERIAL VALLEY DROPPING INTO THE
LOW 60S. WATER VAPOR IMAGERY SHOWS ZONAL FLOW ALOFT OVER SOUTHERN
CALIFORNIA AND ARIZONA WITH A LOW MOVING INTO NORTHERN CALIFORNIA
AND THE PACIFIC NORTHWEST...AND ANOTHER ONE JUST UPSTREAM OF IT.
LATEST PROGS SHOW LOWER LEVEL MOISTURE LINGERING OVER SOUTH-CENTRAL
ARIZONA TODAY WITH A FAIRLY SHARP GRADIENT OVER SOUTHWEST ARIZONA
AND WESTERN MARICOPA COUNTY. WARM LAYER ROUGHLY BETWEEN 600-700 MB
WILL LIMIT DEPTH OF CONVECTION TODAY. HOWEVER...JUST ENOUGH MOISTURE
TO CARRY SMALL AREA OF SLIGHT CHANCE POPS IN ZONE 24...FOR NOW.
REGARDING TEMEPRATURES...COOL START OUT WEST MAY LEAD TO SLIGHTLY
LOWER MAX TEMPS FOR TODAY...BUT DRIER AIR WILL ENABLE LARGER DIURNAL
RANGE WHICH SHOULD OFFSET THE COOLER START. JUST SOME MINOR WIND AND
DEW POINT UPDATES IN THE GRIDS THIS MORNING.
PROGS CONTINUE TO SHOW EVEN LESS MOISTURE AVAILABLE MONDAY AS THE
LOWS CURRENTLY WELL TO OUR NORTHWEST MOVE THROUGH THE INTERIOR WEST.
SYSTEMS WILL PASS FAR ENOUGH TO OUR NORTH THAT THERE WILL BE LITTLE
EFFECT ON OUR AREA. BEHIND THE TROUGH...THE RIDGE CENTERED OVER
MEXICO WILL EXPAND NORTHWARD ON TUESDAY THOUGH THERE WONT BE A BIG
CHANGE IN HEIGHTS AND THICKNESSES. THUS LITTLE CHANGE IN TEMPS.
PREVIOUS DISCUSSION...
SAT IMAGERY EARLY THIS MORNING SHOWS MOSTLY CLEAR/CLEAR SKIES OVER
SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA. 24 HR
CHANGE PRODUCT INDICATES SFC DEW POINTS FROM THE CO RIVER WESTWARD
ARE RUNNING 15-20 DEG LOWER THAN THIS TIME YESTERDAY. THE DRIER
CONDITIONS AND CLEAR SKIES WILL ALLOW FOR MAXIMUM RADIATIONAL
COOLING OVERNIGHT...WITH THIS MORNING/S LOWS OUT WEST RUNNING 4-7
DEG COOLER THAN SATURDAY MORNING. NOT AS MUCH DRYING OVER THE LOWER
SOUTH-CENTRAL ARIZONA DESERTS...AND CURRENT IR SAT TRENDS EVEN SHOW
A FEW LOW LEVEL CLOUDS OVER PORTIONS OF NORTHWESTERN PINAL AND
SOUTHERN GILA COUNTY. THE KSPR 00 UTC SUN SOUNDING FROM EARLIER
INDICATES AN INCREASE IN MOISTURE (OVER 24 HOURS AGO) WITH A FAIRLY
MOIST LAYER BETWEEN 800-750MB (AROUND 8K-15K FT). WITH THE LINGERING
MID LEVEL MOISTURE IN PLACE...THE INHERITED SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN EAST OF
PHOENIX...OVER PORTIONS OF SOUTHERN GILA COUNTY...FOR THIS
AFTERNOON/EARLY EVENING LOOKS GOOD. ELSEWHERE...A DRY FORECAST
REMAIN IN PLACE. AS FOR TEMPS...THE FLAT RIDGE (IN RESPONSE TO THE
TROUGH MOVING BY WELL TO THE NORTH) WILL RESULT IN LITTLE CHANGE IN
HIGH TEMPS TODAY WITH THE WARMEST DESERT LOCALES AROUND 100 DEG.
MONDAY THROUGH THE REST OF THE WEEK...THE MORE POTENT LOW MOVING
THROUGH THE PAC NW/NRN ROCKIES THIS WEEKEND WILL GIVE WAY TO A BROAD
TROUGH OVER MUCH OF THE WESTERN CONUS MON/TUES. AS IT DOES SO...THE
LARGE ANTI-CYCLONE (PROGGED BY THE MODELS FOR THE PAST SEVERAL RUNS)
WILL BUILD OVER THE GREATER SOUTHWEST. EVEN WITH THE HIGH IN PLACE
THE MID TO LATTER PART OF THE WEEK...MODELS ARE NOT INDICATING MUCH
OF AN INCREASE IN THICKNESS/500MB HEIGHTS...SO DO NOT EXPECT MUCH
DAY TO DAY CHANGE IN TEMPS. MEANWHILE...SKIES WILL REMAIN MOSTLY
CLEAR...WITH A FEW AFTERNOON CU POSSIBLE OVER THE HIGHER TERRAIN TO
THE EAST. WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS...WITH WESTERLY
BREEZES/GUSTS AROUND 15-20 MPH AT TIMES DURING PEAK HEATING EACH DAY
THIS UPCOMING WEEK.
&&
.AVIATION...
BIGGEST AVIATION CONCERN FOR SUN APPEARS TO BE THE POTENTIAL FOR
GUSTY WINDS AT KPHX. ALTHOUGH WINDS ARE GENERALLY EXPECTED TO BE
UNDER 10 KT AT THE SURFACE...THE FLOW ALOFT WILL STRENGTHEN AHEAD OF
A TROUGH MOVING THROUGH THE INTERMOUNTAIN WEST. WIND GUSTS MAY REACH
25 KT IN THE PHOENIX METRO AREA THIS AFTERNOON AND POSSIBLY THIS
EVENING AS WELL. OTHERWISE...CONVECTIVE CU WILL DEVELOP ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX THIS AFTERNOON...THOUGH THUNDERSTORM
PROBABILITIES WILL GENERALLY BE AROUND 5 PERCENT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...HIRSCH
FIRE WEATHER...SIPPLE
000
FXUS66 KHNX 211630
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
930 AM PDT SUN SEP 21 2008
.DISCUSSION...UPPER TROUGH CONTINUES TO EXIT THE WEST WITH A ZONAL
FLOW PATTERN REMAINING OVER CALIFORNIA. THIS FLOW PATTERN WILL
FURTHER THE COOLING OBSERVED BY THE DISTRICT AS AFTERNOON HIGHS
MAY ONLY REACH THE LOWER 80S. CURRENTLY AS OF 900 AM PDT...MANY
LOCATIONS WERE IN THE 60S AND A FEW DEG-F COOLER FROM THAT OF
SATURDAY MORNING. SHORT RANGE MODELS ARE STILL PROGGING ANOTHER
SHORT WAVE TROF TO PUSH THROUGH NORTHERN CALIFORNIA WITH ANOTHER
SHOT OF COOL AIR SURGING INTO THE DISTRICT. THIS WILL MAINTAIN THE
COOL DOWN THROUGH MONDAY WITH THE START OF A WARM UP ON TUESDAY.
BEYOND THIS WEEKEND...TEMPERATURES ARE STILL EXPECTED TO CLIMB TO
ABOVE SEASONAL NORMS BY MID WEEK AS HIGH PRESSURE BEGIN TO
DOMINATE THE WEST COAST. NO WEATHER EXPECTED DURING THE NEXT SEVEN
DAYS...SO NO UPDATES NEEDED THIS MORNING.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA
INTERIOR THROUGH 18Z MONDAY.
&&
.AIR QUALITY ISSUES...ON SUNDAY SEPTEMBER 21 2008...
UNHEALTHY FOR SENSITIVE GROUPS IN KERN COUNTY. FURTHER INFORMATION
IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...SANGER
WEATHER.GOV/HANFORD
000
FXUS66 KSGX 211623
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 AM PDT SUN SEP 21 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. WEAK UPPER LEVEL LOW PRESSURE WILL KEEP MOST TEMPERATURES
BELOW SEASONAL AVERAGES THROUGH MONDAY. BREEZY IN THE MOUNTAINS AND
DESERTS AT TIMES. WARMER DURING THE SECOND HALF OF THE WEEK UNDER
HIGH PRESSURE THEN COOLER AGAIN TOWARD NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A COASTAL EDDY HAS CAUSED THE MARINE LAYER TO DEEPEN THIS MORNING
AND LOW CLOUDS HAVE SPREAD ALL THE WAY INTO THE INLAND EMPIRE. THE
12Z KNKX SOUNDING PLACES THE MARINE INVERSION NEAR 2300 FT...AND
METAR OBSERVATIONS INDICATE THAT A FAIRLY THIN CLOUD DECK IN PLACE.
NORMALLY THIS WOULD SUGGEST RAPID CLEARING...HOWEVER CLEARING COULD
BE DELAYED IN SOME AREAS DUE TO THE EDDY AND COOLER SURFACE TEMPS.
A TROUGH OF LOW PRESSURE OVER THE WESTERN STATES WILL KEEP TEMPS
BELOW SEASONAL AVERAGES WITH CONTINUING NIGHT AND MORNING LOW CLOUDS
AND FOG INTO MONDAY. THE 12Z KNKX SOUNDING SHOWED MINOR WARMING WITH
VEERING WINDS ABOVE 3000 FT...BUT COOLING WITHIN THE MARINE LAYER.
THIS WILL KEEP TEMPS SIMILAR OR SLIGHTLY COOLER THAN YESTERDAY IN
MOST AREAS...EXCEPT FOR SOME SLIGHT WARMING IN THE FOOTHILLS AND
MOUNTAINS. SLIGHT WARMING SHOULD OCCUR IN ALL AREAS ON MONDAY AS THE
TROUGH OF LOW PRESSURE BEGINS TO MOVE EAST...BUT TEMPS WILL LIKELY
REMAIN SLIGHTLY BELOW SEASONAL AVERAGES. A COASTAL EDDY WILL SUSTAIN
A 2000 FT DEEP MARIN LAYER AGAIN ON MONDAY MORNING WITH LOW CLOUDS
EXTENDING INTO THE INLAND VALLEYS.
TEMPS SHOULD RETURN TO SEASONAL AVERAGES ON TUESDAY AS HIGH PRESSURE
BEGINS TO BUILD OVER THE DESERT SOUTHWEST. THE MARINE LAYER
INVERSION WILL LOWER AND LOW CLOUDS AND FOG WILL BE CONFINED TO THE
COAST AND WESTERN VALLEYS.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
HIGH PRESSURE OVER THE SOUTHWEST STATES WILL MAINTAIN HIGHER THAN
AVERAGE TEMPS AND A SHALLOWER MARINE LAYER THROUGH THURSDAY. MID
LEVEL MOISTURE IN SOUTH FLOW ALOFT MAY ALSO BRING SOME AFTERNOON
CLOUDS TO THE MOUNTAINS...BUT NO THUNDERSTORMS.
FOR FRIDAY AND SATURDAY...HIGH PRESSURE WILL SHIFT TO THE EAST AS A
WEAK TROUGH OF LOW PRESSURE DEVELOPS OFF THE WEST COAST. THIS WILL
BRING COOLER WEATHER AND A DEEPER MARINE LAYER WITH INCREASING LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS.
&&
.AVIATION...
211500Z...MARINE LAYER ABOUT 2300 FT. BASES AROUND 2K FT MSL. SO
THIN LAYER OF STRATUS WILL CLEAR QUICKLY...BY 17Z. STRATUS RETURNING
LATE AFTERNOON. NOT MUCH CHANGE EXPECTED THROUGH MONDAY AS ANOTHER
TROUGH MOVES THROUGH TO THE NORTH TODAY THROUGH MONDAY MORNING. A
WEAK COASTAL EDDY IS FORECAST TO CONTINUE THROUGH MONDAY MORNING.
OTHERWISE CLEAR.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...SCV
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KMTR 211606
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
915 AM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 9:15 AM PDT SUNDAY...QUIET WEATHER EXPECTED FOR
THE ENTIRE WEEK.
TRICKY TEMPERATURE AND SKY FORECAST FOR TODAY AS THE FORT ORD
PROFILER INDICATES THAT THE MARINE LAYER IS STILL NEXT TO NOTHING
WHILE THE SURFACE PRESSURE GRADIENTS SHOW ONLY A LIGHT ONSHORE FLOW
WHILE THE NORTHERLY COMPONENT IS NEARLY 3 TIMES LARGER. THESE FACTORS
WOULD USUALLY CREATE A FAIRLY FAST BURN-OFF TODAY AND ALLOW
TEMPERATURES TO WARM AT LEAST TO WHAT WE HIT YESTERDAY. HOWEVER THE
24 HOUR CHANGE PRODUCT DOES SHOW A LOT OF PLACES 3 TO 6 DEGREES
COOLER THAN WHAT THEY WERE YESTERDAY WHILE THE HIGH RESOLUTION WRF
MODEL KEEPS CLOUDS AROUND SOUTHERN MONTEREY BAY ALL DAY TODAY AND
DOES NOW SHOW A BURN-OFF FOR OTHER AREAS UNTIL AROUND NOON.
THEREFORE...WILL MONITOR TEMPERATURES OVER THE NEXT COUPLE OF HOURS
AND IF THEY ARE STILL TRENDING COOLER THAN YESTERDAY HIGHS FOR TODAY
WILL BE BUMPED DOWN. CLOUDS MAY ALSO BE INCREASED IF THE WRF STILL
LOOKS LIKE IT HAS A GOOD HANDLE ON THE SITUATION.
PAST THIS AFTERNOON...A TROUGH WILL MOVE ACROSS NORTHERN CALIFORNIA
THIS EVENING AND SHOULD HAVE VIRTUALLY NO IMPACT ON OUR WEATHER.
BEHIND IT A FLAT RIDGE IN ASSOCIATION WITH WARMING ALOFT WILL HELP
TO INCREASE TEMPERATURES AT LEAST THROUGH WEDNESDAY. HIGHS WILL
WARM BACK INTO THE 80S AND 90S FOR MOST INTERIOR LOCATIONS WITH NO
CHANCE OF RAINFALL FORECAST. HOW LONG THE RIDGE STAYS WITH US IS
THE OTHER BIG CHALLENGE FOR THE FORECAST. THAT WILL BE THE MAIN AREA
OF CONCERN FOR THE AFTERNOON PACKAGE.
&&
.AVIATION...AS OF 4:00 AM PDT SUNDAY...STRATUS HAS BEEN MORE PATCHY
DURING THE NIGHT BUT SATELLITE PICTURES SHOW THEY HAVE INCREASED
IN COVERAGE OVER THE PAST HOUR OR SO. STRATUS EXPECTED TO LINGER
OVER THE SFO APPROACH ZONE UNTIL AROUND 18Z AND POSSIBLY A
LITTLE LATER. MRY BAY AREA SHOULD CLEAR OUT AROUND SIMILAR TIMES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: WP/KOPPS
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 211556
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
900 AM PDT SUN SEP 21 2008
.SHORT TERM (TODAY-WEDNESDAY)...
MARINE LAYER A BIT ERRATIC THIS MORNING...WITH DEPTHS RANGING FROM
1000 TO 2200 FT AND STRATUS COVERING MORE LAND THAN OCEAN. A DECENT
EDDY FORMED SOUTH OF POINT CONCEPTION...WHICH IS CONTINUING TO HELP
PUSH THE CLOUDS DEEP INTO THE VALLEYS. THE MARINE INVERSION ITSELF
REMAINS RATHER WEAK EVERYWHERE...AND FULL CLEARING EXPECTED BY NOON
AT THE LATEST. MORNING LOWS WERE ONCE AGAIN CHILLY...ESPECIALLY
WHERE THE CLOUDS AND WINDS STAYED OUT. SPEAKING OF WINDS...GUSTY
NORTHERLY FLOW UP TO 40 MPH MATERIALIZED THROUGH THE I5 CORRIDOR AND
IS SLOWLY WEAKENING THIS MORNING. SBA SUNDOWNER WINDS HOWEVER DID
NOT DO MUCH AS THE SBA-SMX GRAD NEVER DIPPED BELOW -3MB. SOME
NORTHEAST FLOW HAS FORMED OVER SLO AND SBA CO...BUT IS STRUGGLING TO
WORK ITS WAY DOWN TO THE COAST AS THE STRONGER MARINE INVERSION IS
WINNING THE BATTLE THUS FAR. IF THESE WINDS DO WORK THEIR WAY
DOWN...THE WARM FORECASTED TEMPS FOR THE CENTRAL COAST AND SANTA
YNEZ VALLEY SHOULD MATERIALIZE...BUT IF THEY DO NOT TEMPS WILL BE
MUCH COOLER. LEFT TEMPS AS IS FOR NOW IN HOPE OF A LATE MORNING PUSH
ONCE THE CAP WEAKENS...BUT MAY NEED TO PULL TEMPS DOWN IF THIS DOES
NOT HAPPEN IN THE NEXT HOUR OR SO. REST OF FORECAST LOOKS GOOD WITH
COOLER LA/VTU VLY TEMPS FROM YESTERDAY AND MOSTLY SIMILAR ELSEWHERE.
...FROM PREVIOUS DISCUSSION...
GOOD AGREEMENT BETWEEN BOTH NAM AND GFS SOLUTIONS IN INDICATING
LITTLE CHANGE IN THE MARINE LAYER FOR TONIGHT AND MONDAY.
1000-500 MB THICKNESSES STAY ABOUT THE SAME IN BOTH MODELS. AREAL
COVERAGES SHOULD BE SIMILAR WITH MAYBE SLIGHT THICKENING IN THE
MARINE LAYER SOUTH OF POINT CONCEPTION. THIS WILL BE DUE TO AN
EDDY CIRCULATION OVER THE INNER WATERS.
TEMPERATURES COULD BE MIXED FOR MONDAY. 950 MB TEMPERATURES
WARM OVER THE AREA...BUT THICKNESSES STAY AROUND THE SAME.
SURFACE GRADIENTS TREND MORE ONSHORE SOUTH OF POINT CONCEPTION
AND TREND OFFSHORE NORTH OF POINT CONCEPTION. WITH WARMER SEA
SURFACE TEMPERATURES IN PLACE OVER THE INNER WATERS AND AT THE
BEACHES...FORECAST TRENDS SLIGHT WARMER...BUT A WELL-DEVELOPED
EDDY CIRCULATION COULD PUT THE DAMPER ON THE TREND.
1000-500 MB THICKNESSES AND 950 MB TEMPERATURES TREND UPWARD FOR
MIDWEEK WITH NEUTRAL TO OFFSHORE TRENDING SURFACE GRADIENTS.
MARINE LAYER WILL REMAIN OVER THE COASTAL SECTION...BUT A
DECREASING INFLUENCE IN COVERAGE AND DEPTH WILL LIKELY BRING
WARMER TEMPERATURES TO THE AREA FOR MIDWEEK.
.LONG TERM (THURSDAY-SATURDAY)...SOUTH TO SOUTHWEST FLOW ALOFT
WILL LIKELY REDEVELOP FOR LATE WEEK BRINGING AN INCREASE IN
MARINE LAYER MOISTURE. GFS SOLUTIONS COULD DEVELOP A EDDY
CIRCULATION OVER THE INNER WATERS WITH SOME LOCAL DRIZZLE
POSSIBLE...BUT ECMWF SOLUTIONS DOWNPLAY THE SCENARIO. AT THE VERY
LEAST...A COOLING TREND SHOULD DEVELOP FOR LATE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...
21/1145Z.
MARINE LAYER UP TO ABOUT 1400 FEET DEEP AND CAPPED BY A VERY WEAK
INVERSION. EDDY DID NOT FORM AND AS A RESULT LOW CLOUDS ARE MUCH
MORE RANDOM IN NATURE. DUE TO HIGH LEVEL OF THE MARINE LAYER SOME
VALLEYS HAVE MORE CLOUDS THAN THE NEIGHBORING COASTAL SECTIONS.
CLOUDS SHOULD RETURN A FEW HOURS EARLIER TONIGHT AND WITH MORE
COMPLETE COVERAGE.
KLAX...CLOUDS WILL MOVE IN OVER AND OUT OF THE AIR FIELD THROUGH MID
MORNING. A 30 PERCENT CHANCE OF 1500 FOOT CIGS FROM 16Z TO 20Z.
CLOUDS WILL MOST LIKELY RETURN AROUND 08Z BUT COULD ARRIVE AS LATE
AS 11Z.
KBUR...GOOD CONFIDENCE IN 17Z BURN OFF TIME..SCT CLOUDS NR 015 WILL
LIKELY PERSIST THROUGH 20Z. CIGS COULD ARRIVE AS EARLY AS 09Z
TONIGHT BUT 11Z IS THE MOST LIKELY TIME.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL/HALL
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSTO 211546
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
845 AM PDT SUN SEP 21 2008
.DISCUSSION...
LONG WAVE TROUGH ALONG THE WEST COAST WITH A WEAK SHORT WAVE MOVING
ACROSS NORCAL THIS MORNING PRODUCING SOME CLOUDINESS ACROSS THE
NORTHERN INTERIOR. THIS WAVE MOVES THROUGH THIS MORNING AS ANOTHER
APPROACHES THIS AFTERNOON INTO TONIGHT. NAM12 AND LOCAL RUN
WRF_NMM... INITIALIZED BY NAM...FORECAST SOME INSTABILITY AND
RESULTANT LIGHT SCATTERED QPF ACROSS NORTHERN PORTIONS OF SHASTA AND
NORTHWEST PLUMAS COUNTIES EARLY THIS EVENING WHILE GFS MAINTAINS
WEAKER FEATURE WITH LESS INSTABILITY AND DRIRE FORECAST. WILL UPDATE
TO ADD A SLIGHT CHANCE POPS FOR THESE AREAS FOR EARLY THIS EVENING.
OTHERWISE CONTINUED BELOW NORMAL TEMPERATURES TODAY WITH MAX
READINGS GENERALLY IN THE LOWER TO MID 80S FOR THE INTERIOR VALLEY
AND 60S TO 70S FOR THE FOOTHILLS AND MOUNTAINS.
PCH
&&
.AVIATION...
VFR CONDS WILL CONTINUE TODAY. MOSTLY CLEAR SKIES FOR THE SOUTHERN
SAC AND NORTHERN SAN JOAQUIN VALLEYS WITH A SMALL AREA OF LOW LEVEL
MARINE STRATUS NUDGING INTO THE DELTA AREA THIS MORNING. FEW TO SCT
MID AND HIGH CLOUDS AFFECTING THE CENTRAL AND NORTHERN SAC VALLEY
INCLUDING THE SURROUNDING MOUNTAINS. WINDS WILL REMAIN LIGHT TODAY
BUT THE NORTH-SOUTH GRADIENT FROM MFR-SAC WILL INCREASE UP TO 7 MB
FROM 06-18Z. THIS SLIGHT ENHANCEMENT SHOULD ONLY AFFECT THE NORTHERN
SAC VALLEY...WINDS SHOULD STILL REMAIN UNDER 10 KTS AT THE SURFACE
WITH MORE MODERATE WINDS AROUND 20 KTS NEAR 1000-2000 FT AGL. LIGHT
SHOWERS MAY AFFECT THE HIGHER ELEVATIONS OF EASTERNMOST SHASTA
COUNTY INCLUDING THE LASSEN PARK AREA THROUGH 06Z. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KREV 211505 AAA
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
800 AM PDT SUN SEP 21 2008
.UPDATE...
JUST A QUICK UPDATE TO INCREASE RIDGE GUSTS OVER MONO COUNTY THROUGH
TODAY. MESOWEST DATA SHOWING GUSTS TO 50 MPH AT MAMMOTH AND WHITE
MTNS, 40 MPH AT MT WARREN. BASED ON UPPER LEVEL WIND FCSTS ASSOC
WITH INCOMING JET, RIDGE WINDS WILL LIKELY STAY UP THROUGH MON
MORNING. REST OF FCST UNCHANGED ATTM.
CS
&&
.SHORT TERM...
A WEAK SHORTWAVE TROUGH SEEN ON WATER VAPOR IMAGERY THIS
MORNING...IS APPROACHING THE NORTHERN CALIFORNIA COAST. THIS WAVE
WILL NOT HAVE VERY MUCH MOISTURE ASSOCIATED WITH IT...ALTHOUGH WITH
A FAVORABLE REGION OF THE UPPER LEVEL JET MOVING IN OVERHEAD THERE
REMAINS A SLIGHT CHANCE FOR A THUNDER SHOWER NORTH OF SUSANVILLE AND
GERLACH THIS EVENING. ANY SHOWERS THAT DO DEVELOP WILL MOVE EAST
INTO NORTHERN PERSHING COUNTY BEFORE MIDNIGHT. WINDS WILL INCREASE
IN THE AFTERNOON OUT OF THE WEST WITH GUSTS UP TO 25 TO 30 MPH.
AFTER THIS SHORTWAVE DEPARTS THE AREA...ZONAL FLOW WILL RETURN TO
THE AREA. WE SHOULD SEE AN INCREASE OF HEIGHTS AND TEMPERATURES
ALOFT...WITH SOME AFTERNOON WESTERLIES AND VALLEY TEMPS WARMING UP
SEVERAL DEGREES EACH DAY MON-TUES. HOON
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
FEW CHANGES MADE TO A PRECIPITATION-FREE FORECAST FOR THE EXTENDED
PERIOD. RIDGE OVER THE SOUTHWEST CONUS KEEPS SHORT WAVE ENERGY AND
ASSOCIATED MOISTURE AND PRECIPITATION NORTH OF NEVADA ON WEDNESDAY.
A STRONGER TROUGH APPROACHES THE WEST COAST BY FRIDAY...INITIALLY
DRAWING MID LEVEL MOISTURE INTO SOUTHERN AND EASTERN ZONES. WILL ADD
PARTLY CLOUDY SKIES TO MONO AND MINERAL COUNTIES ON FRIDAY BEFORE A
STRONGER SOUTHWEST FLOW PUSHES THAT MOISTURE EAST OF THE AREA ON
SATURDAY. TEMPERATURES REMAIN ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH 12Z MONDAY. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KMTR 211216
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
400 AM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 4:00 AM PDT SUNDAY...NO MAJOR FORECAST CONCERNS
IN THE SHORT AND LONG TERM AS PLEASANT SEPTEMBER WEATHER APPEARS TO
BE ON TAP.
CLOUD COVER IS MUCH LESS EXTENSIVE THIS MORNING COMPARED TO 24
HOURS AGO. THERE ARE PATCHES OF STRATUS AROUND BOTH SF AND MRY BAY
BUT THESE WILL QUICKLY DISPERSE AFTER SUNRISE WITH NO APPARENT
MARINE INVERSION PRESENT. MORE SUNSHINE TO START THE DAY AND THE
BEGINNING OF A WARMING TREND AT 850 MB WILL ALLOW TEMPERATURES TO
WARM SEVERAL DEGREES FROM SATURDAYS HIGHS. TONIGHT INTO MONDAY
MORNING A NORTHERLY GRADIENT WILL DEVELOP AT THE SURFACE AND IN THE
THE LOWER LEVELS WITH LIGHT NORTH/NORTHEAST WINDS DEVELOPING IN THE
NORTH BAY HILLS. EXPECT WARMER TEMPERATURES TONIGHT IN THE HILLS AS
850 MB TEMPS TREND UPWARD. HOWEVER UNDER MOSTLY CLEAR SKIES TEMPS MAY
COOL IN THE VALLEYS GIVEN BETTER RADIATION. WARMING TREND THEN
CONTINUES INTO MONDAY AND TUESDAY WITH THE GRIDS ATTEMPTING TO
REFLECT A PERIOD OF ABOVE NORMAL TEMPERATURES FOR MOST OF THE CWA.
MOSTLY CLEAR SKIES SHOULD CONTINUE AT LEAST THROUGH MIDWEEK AND
LIKELY INTO THURSDAY WITH 850 MB TEMPS PEAKING AROUND 22-23 DEGREES
CELSIUS BY WEDS OR THURSDAY DEPENDING ON MODEL SELECTION. THIS
SHOULD LEAD TO WIDESPREAD READINGS INTO THE 80S AND LOWER 90S FOR
INLAND AREAS WITH 70S EVEN NEAR THE COAST.
BY FRIDAY THE FORECAST CONFIDENCE DECREASES DRAMATICALLY. THE 00Z
ECMWF STARTS TO BUILD A FAIRLY STRONG RIDGE THROUGH MOST OF THE
7-10 DAY TIME FRAME WHICH IS A CHANGE OF SOLUTIONS FROM PREVIOUS
DAYS. THE GFS BRINGS A WEAK TROUGH INTO THE AREA BY FRIDAY AND INTO
THE WEEKEND WHICH WOULD LEAD TO INCREASED CLOUD COVER AND COOLER
TEMPS. FOR THE MOST PART MADE LITTLE CHANGE TO THE EXTENDED AND WILL
LEAN TOWARDS CLIMO UNTIL BETTER MODEL AGREEMENT ENSUES.
&&
.AVIATION...AS OF 4:00 AM PDT SUNDAY...STRATUS HAS BEEN MORE PATCY
DURING THE NIGHT BUT SATELLITE PICTURES SHOW THEY HAVE INCREASED
IN COVERAGE OVER THE PAST HOUR OR SO. STRATUS EXPECTED TO LINGER
OVER THE SFO APPROACH ZONE UNTIL AROUND 18Z AND POSSIBLY A
LITTLE LATER. MRY BAY AREA SHOULD CLEAR OUT AROUND SIMILAR TIMES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: RW
AVIATION/MARINE: WP
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 211215
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
400 AM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 4:00 AM PDT SUNDAY...NO MAJOR FORECAST CONCERNS
IN THE SHORT AND LONG TERM AS PLEASANT SEPTEMBER WEATHER APPEARS TO
BE ON TAP.
CLOUD COVER IS MUCH LESS EXTENSIVE THIS MORNING COMPARED TO 24
HOURS AGO. THERE ARE PATCHES OF STRATUS AROUND BOTH SF AND MRY BAY
BUT THESE WILL QUICKLY DISPERSE AFTER SUNRISE WITH NO APPARENT
MARINE INVERSION PRESENT. MORE SUNSHINE TO START THE DAY AND THE
BEGINNING OF A WARMING TREND AT 850 MB WILL ALLOW TEMPERATURES TO
WARM SEVERAL DEGREES FROM SATURDAYS HIGHS. TONIGHT INTO MONDAY
MORNING A NORTHERLY GRADIENT WILL DEVELOP AT THE SURFACE AND IN THE
THE LOWER LEVELS WITH LIGHT NORTH/NORTHEAST WINDS DEVELOPING IN THE
NORTH BAY HILLS. EXPECT WARMER TEMPERATURES TONIGHT IN THE HILLS AS
850 MB TEMPS TREND UPWARD. HOWEVER UNDER MOSTLY CLEAR SKIES TEMPS MAY
COOL IN THE VALLEYS GIVEN BETTER RADIATION. WARMING TREND THEN
CONTINUES INTO MONDAY AND TUESDAY WITH THE GRIDS ATTEMPTING TO
REFLECT A PERIOD OF ABOVE NORMAL TEMPERATURES FOR MOST OF THE CWA.
MOSTLY CLEAR SKIES SHOULD CONTINUE AT LEAST THROUGH MIDWEEK AND
LIKELY INTO THURSDAY WITH 850 MB TEMPS PEAKING AROUND 22-23 DEGREES
CELSIUS BY WEDS OR THURSDAY DEPENDING ON MODEL SELECTION. THIS
SHOULD LEAD TO WIDESPREAD READINGS INTO THE 80S AND LOWER 90S FOR
INLAND AREAS WITH 70S EVEN NEAR THE COAST.
BY FRIDAY THE FORECAST CONFIDENCE DECREASES DRAMATICALLY. THE 00Z
ECMWF STARTS TO BUILD A FAIRLY STRONG RIDGE THROUGH MOST OF THE
7-10 DAY TIME FRAME WHICH IS A CHANGE OF SOLUTIONS FROM PREVIOUS
DAYS. THE GFS BRINGS A WEAK TROUGH INTO THE AREA BY FRIDAY AND INTO
THE WEEKEND WHICH WOULD LEAD TO INCREASED CLOUD COVER AND COOLER
TEMPS. FOR THE MOST PART MADE LITTLE CHANGE TO THE EXTENDED AND WILL
LEAN TOWARDS CLIMO UNTIL BETTER MODEL AGREEMENT ENSUES.
&&
.AVIATION...AS OF 4:00 AM PDT SUNDAY...STRATUS HAS BEEN MORE PATCY
DURING THE NIGHT BUT SATELLITE PICTURES SHOW THEY HAVE INCREASED
IN COVERAGE OVER THE PAST HOUR OR SO. STRATUS EXPECTED TO LINGER
OVER THE SFO APPROACH ZONE UNTIL AROUND 18Z AND POSSIBLY A
LITTLE LATER.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: RW
AVIATION/MARINE: WP
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KEKA 211209
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
509 AM PDT SUN SEP 21 2008
.SYNOPSIS...A WEAK UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION
TODAY AND BRING AN INCREASE IN MID AND HIGH CLOUDS TO LOCATIONS
NORTH CAPE MENDOCINO...OTHERWISE PARTLY CLOUDY SKIES WILL PREVAIL.
THE COOL TEMPERATURES WILL CONTINUE OVER THE INTERIOR TODAY. LATE
NIGHT AND MORNING LOW CLOUDS AND PATCHY FOG EXPECTED TO FORM NEAR
THE COAST TONIGHT. WEAK HIGH PRESSURE WILL BRING A WARMING TREND TO
INLAND LOCATIONS BEGINNING MONDAY.
&&
.SHORT TERM...TODAY TROUGH TUESDAY...A WEAK TROUGH WILL PASS THROUGH
THE PACIFIC NORTHWEST TODAY...BUT WILL BRING LITTLE CHANGE TO THE
WEATHER OTHER THAN TO INCREASE THE MID AND HIGH CLOUD COVERAGE IN
THE NORTHERN PORTION OF THE CWA. BEHIND THIS TROUGH...WEAK RIDGING
WILL BUILD OVER THE PACIFIC NORTHWEST ON MONDAY AND BRING A WARMING
AND DRYING TREND TO INLAND AREAS THROUGH TUESDAY. KENNEDY
.LONG TERM...WEDNESDAY THROUGH SATURDAY...THE WEAK UPPER RIDGE OVER
THE PACIFIC NORTHWEST WILL SHIFT EASTWARD TUESDAY NIGHT IN RESPONSE
TO AN APPROACHING UPPER TROUGH. THIS TROUGH IS STILL FORECAST TO
CROSS 130 W LONGITUDE BY 1200 UTC (5AM) WEDNESDAY. THIS FEATURE IS
FORECAST TO WEAKEN AS IT APPROACHES THE COAST...HOWEVER STILL
APPEARS TO HAVE SUFFICIENT MOISTURE TO PRODUCE A SLIGHT CHANCE OF
LIGHT RAIN OVER THE EXTREME NORTHERN PORTION OF THE CWA WEDNESDAY
AFTERNOON AND EVENING. THE SYNOPTIC MODELS ARE IN FAIR AGREEMENT ON
THE STRENGTH AND TIMING OF THIS FEATURE. THE ECMWF IS STILL
INDICATING A STRONGER AND DEEPER TROUGH. WITH LITTLE CONSENSUS ON
THIS SYSTEM...DID TAPER BACK THE POP FORECAST FOR WEDNESDAY
AFTERNOON AND EVENING. THE MODELS REMAIN IN REASONABLE AGREEMENT
IN DEPICTING SHORT WAVE RIDGING FOR THE REGION THURSDAY AND FRIDAY
AHEAD OF ANOTHER TROUGH FOR LATE FRIDAY INTO SATURDAY. CMC/KENNEDY
&&
.AVIATION...WEAK UPPER LEVEL SHORTWAVE APPROACHING THE AREA HAS
BROUGHT SCT-BKN MID AND HIGH CLOUDS OVER NORTHWEST CALIFORNIA THIS
MORNING. HIGH CLOUDS APPEAR TO BE DISRUPTING IFR DECK THAT IS
PRESENT OVER HUMBOLDT BAY AND THE EEL RIVER DELTA...SO EXPECT THE
VARIABLE IFR TO VFR CIGS AND VSBYS TO CONTINUE AT KACV AND ADJACENT
AREAS. LOW CLOUDS ARE EXPECTED TO SCOUR OUT LATER TODAY AS
NORTHWESTERLY WINDS INCREASE LATER THIS MORNING...WITH MAINLY
MID-HIGH CLOUDS REMAINING ACROSS THE REGION. MOUNTAINS COULD SEE
ANOTHER ROUND OF ALTOCU DEVELOPMENT LATER TODAY. ALM
&&
.MARINE...N-NW WINDS WILL INCREASE TODAY AS HIGH PRESSURE BUILDS
OVER THE EAST PACIFIC. WINDS ARE EXPECTED TO INCREASE TO SCA
LEVELS OVER THE SOUTHERN OUTER WATERS LATER THIS MORNING AS THE
GRADIENT TIGHTENS...THE TIMING OF WHICH STILL LOOKS GOOD BY
MORNING LAPS ANALYSIS THAT SHOW WINDS BEGINNING TO REACH INTO THE
15-20KT RANGE.
MODERATE SCA CONDITIONS ARE EXPECTED TO SPREAD INTO THE NORTHERN
OUTER WATERS ON MONDAY. COVERAGE AND DURATION OF GALE FORCE GUSTS IS
STILL UNCERTAIN AS MODELS ARE INCONSISTENT IN THEIR PLACEMENT OF THE
FRONT THAT IS EXPECTED TO CLIP THE REGION ON WEDNESDAY. THE TREND
HOWEVER HAS BEEN FOR A SLOWER SYSTEM ON WEDNESDAY...AND WEAKER WINDS
FOR TUESDAY. HAVE FOREGONE A GALE WATCH/WARNING WITH THIS
PACKAGE...THINKING THAT GUSTS MAY BE MORE ISOLD IN NATURE.
WINDS WILL DROP BRIEFLY ON WEDNESDAY AS THE FRONT PUSHES
THROUGH...AND REBUILD ON THURSDAY. W-NW SWELL TRAIN WITH THIS SYSTEM
WILL BEGIN TO BUILD OVER THE REGION MID TO LATE WEDNESDAY. ALM
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR WINDS AND HAZARDOUS SEAS IN EFFECT FROM
11 AM THIS MORNING TO 2 PM PDT TUESDAY FROM CAPE MENDOCINO TO
POINT ARENA OUT 10 TO 60NM.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KLOX 211152
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
445 AM PDT SUN SEP 21 2008
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (TODAY-WEDNESDAY)...MARINE LAYER IS PATCHY THIS
MORNING WITH WEAK INVERSION IN PLACE AND MARINE LAYER DEPTH
AROUND 1500 FEET. FORECAST HAS INCREASED MARINE LAYER PRESENCE IN
SAN FERNANDO VALLEYS BUT DECREASE STRATUS DEVELOPMENT IN THE
SALINAS RIVER VALLEY. OTHERWISE...PATCHY FORECAST SEEMS TO WORK
OUT FOR THIS MORNING WITH WEAK INVERSION IN PLACE. TEMPERATURES
WERE WARMED SLIGHTLY WITH WEAK MARINE INVERSION IN PLACE AND A
SLIGHT OFFSHORE TREND OCCURRING THIS MORNING.
GOOD AGREEMENT BETWEEN BOTH NAM AND GFS SOLUTIONS IN INDICATING
LITTLE CHANGE IN THE MARINE LAYER FOR TONIGHT AND MONDAY.
1000-500 MB THICKNESSES STAY ABOUT THE SAME IN BOTH MODELS. AREAL
COVERAGES SHOULD BE SIMILAR WITH MAYBE SLIGHT THICKENING IN THE
MARINE LAYER SOUTH OF POINT CONCEPTION. THIS WILL BE DUE TO AN
EDDY CIRCULATION OVER THE INNER WATERS.
TEMPERATURES COULD BE MIXED FOR MONDAY. 950 MB TEMPERATURES
WARM OVER THE AREA...BUT THICKNESSES STAY AROUND THE SAME.
SURFACE GRADIENTS TREND MORE ONSHORE SOUTH OF POINT CONCEPTION
AND TREND OFFSHORE NORTH OF POINT CONCEPTION. WITH WARMER SEA
SURFACE TEMPERATURES IN PLACE OVER THE INNER WATERS AND AT THE
BEACHES...FORECAST TRENDS SLIGHT WARMER...BUT A WELL-DEVELOPED
EDDY CIRCULATION COULD PUT THE DAMPER ON THE TREND.
1000-500 MB THICKNESSES AND 950 MB TEMPERATURES TREND UPWARD FOR
MIDWEEK WITH NEUTRAL TO OFFSHORE TRENDING SURFACE GRADIENTS.
MARINE LAYER WILL REMAIN OVER THE COASTAL SECTION...BUT A
DECREASING INFLUENCE IN COVERAGE AND DEPTH WILL LIKELY BRING
WARMER TEMPERATURES TO THE AREA FOR MIDWEEK.
.LONG TERM (THURSDAY-SATURDAY)...SOUTH TO SOUTHWEST FLOW ALOFT
WILL LIKELY REDEVELOP FOR LATE WEEK BRINGING AN INCREASE IN
MARINE LAYER MOISTURE. GFS SOLUTIONS COULD DEVELOP A EDDY
CIRCULATION OVER THE INNER WATERS WITH SOME LOCAL DRIZZLE
POSSIBLE...BUT ECMWF SOLUTIONS DOWNPLAY THE SCENARIO. AT THE VERY
LEAST...A COOLING TREND SHOULD DEVELOP FOR LATE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...
21/1145Z.
MARINE LAYER UP TO ABOUT 1400 FEET DEEP AND CAPPED BY A VERY WEAK
INVERSION. EDDY DID NOT FORM AND AS A RESULT LOW CLOUDS ARE MUCH
MORE RANDOM IN NATURE. DUE TO HIGH LEVEL OF THE MARINE LAYER SOME
VALLEYS HAVE MORE CLOUDS THAN THE NEIGHBORING COASTAL SECTIONS.
CLOUDS SHOULD RETURN A FEW HOURS EARLIER TONIGHT AND WITH MORE
COMPLETE COVERAGE.
KLAX...CLOUDS WILL MOVE IN OVER AND OUT OF THE AIR FIELD THROUGH MID
MORNING. A 30 PERCENT CHANCE OF 1500 FOOT CIGS FROM 16Z TO 20Z.
CLOUDS WILL MOST LIKELY RETURN AROUND 08Z BUT COULD ARRIVE AS LATE
AS 11Z.
KBUR...GOOD CONFIDENCE IN 17Z BURN OFF TIME..SCT CLOUDS NR 015 WILL
LIKELY PERSIST THROUGH 20Z. CIGS COULD ARRIVE AS EARLY AS 09Z
TONIGHT BUT 11Z IS THE MOST LIKELY TIME.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...HALL
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 211148
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN TODAY. OTHERWISE
...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT SOUTHWEST
THE NEXT COUPLE DAYS...AS AN AREA OF LOW PRESSURE PASSES TO THE
NORTH. DRY CONDITIONS WILL CONTINUE THIS WEEK...UNDER MOSTLY CLEAR
SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
SAT IMAGERY EARLY THIS MORNING SHOWS MOSTLY CLEAR/CLEAR SKIES OVER
SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA. 24 HR
CHANGE PRODUCT INDICATES SFC DEW POINTS FROM THE CO RIVER WESTWARD
ARE RUNNING 15-20 DEG LOWER THAN THIS TIME YESTERDAY. THE DRIER
CONDITIONS AND CLEAR SKIES WILL ALLOW FOR MAXIMUM RADIATIONAL
COOLING OVERNIGHT...WITH THIS MORNING/S LOWS OUT WEST RUNNING 4-7
DEG COOLER THAN SATURDAY MORNING. NOT AS MUCH DRYING OVER THE LOWER
SOUTH-CENTRAL ARIZONA DESERTS...AND CURRENT IR SAT TRENDS EVEN SHOW
A FEW LOW LEVEL CLOUDS OVER PORTIONS OF NORTHWESTERN PINAL AND
SOUTHERN GILA COUNTY. THE KSPR 00 UTC SUN SOUNDING FROM EARLIER
INDICATES AN INCREASE IN MOISTURE (OVER 24 HOURS AGO) WITH A FAIRLY
MOIST LAYER BETWEEN 800-750MB (AROUND 8K-15K FT). WITH THE LINGERING
MID LEVEL MOISTURE IN PLACE...THE INHERITED SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN EAST OF
PHOENIX...OVER PORTIONS OF SOUTHERN GILA COUNTY...FOR THIS
AFTERNOON/EARLY EVENING LOOKS GOOD. ELSEWHERE...A DRY FORECAST
REMAIN IN PLACE. AS FOR TEMPS...THE FLAT RIDGE (IN RESPONSE TO THE
TROUGH MOVING BY WELL TO THE NORTH) WILL RESULT IN LITTLE CHANGE IN
HIGH TEMPS TODAY WITH THE WARMEST DESERT LOCALES AROUND 100 DEG.
MONDAY THROUGH THE REST OF THE WEEK...THE MORE POTENT LOW MOVING
THROUGH THE PAC NW/NRN ROCKIES THIS WEEKEND WILL GIVE WAY TO A BROAD
TROUGH OVER MUCH OF THE WESTERN CONUS MON/TUES. AS IT DOES SO...THE
LARGE ANTI-CYCLONE (PROGGED BY THE MODELS FOR THE PAST SEVERAL RUNS)
WILL BUILD OVER THE GREATER SOUTHWEST. EVEN WITH THE HIGH IN PLACE
THE MID TO LATTER PART OF THE WEEK...MODELS ARE NOT INDICATING MUCH
OF AN INCREASE IN THICKNESS/500MB HEIGHTS...SO DO NOT EXPECT MUCH
DAY TO DAY CHANGE IN TEMPS. MEANWHILE...SKIES WILL REMAIN MOSTLY
CLEAR...WITH A FEW AFTERNOON CU POSSIBLE OVER THE HIGHER TERRAIN TO
THE EAST. WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS...WITH WESTERLY
BREEZES/GUSTS AROUND 15-20 MPH AT TIMES DURING PEAK HEATING EACH DAY
THIS UPCOMING WEEK.
&&
.AVIATION...
BIGGEST AVIATION CONCERN FOR SUN APPEARS TO BE THE POTENTIAL FOR
GUSTY WINDS AT KPHX. ALTHOUGH WINDS ARE GENERALLY EXPECTED TO BE
UNDER 10 KT AT THE SURFACE...THE FLOW ALOFT WILL STRENGTHEN AHEAD OF
A TROUGH MOVING THROUGH THE INTERMOUNTAIN WEST. WIND GUSTS MAY REACH
25 KT IN THE PHOENIX METRO AREA THIS AFTERNOON AND POSSIBLY THIS
EVENING AS WELL. OTHERWISE...CONVECTIVE CU WILL DEVELOP ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX THIS AFTERNOON...THOUGH THUNDERSTORM
PROBABILITIES WILL GENERALLY BE AROUND 5 PERCENT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...HIRSCH
FIRE WEATHER...SIPPLE
000
FXUS66 KMTR 211053
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
400 AM PDT SUN SEP 21 2008
.DISCUSSION...AS OF 4:00 AM PDT SUNDAY...NO MAJOR FORECAST CONCERNS
IN THE SHORT AND LONG TERM AS PLEASANT SEPTEMBER WEATHER APPEARS TO
BE ON TAP.
CLOUD COVER IS MUCH LESS EXTENSIVE THIS MORNING COMPARED TO 24
HOURS AGO. THERE ARE PATCHES OF STRATUS AROUND BOTH SF AND MRY BAY
BUT THESE WILL QUICKLY DISPERSE AFTER SUNRISE WITH NO APPARENT
MARINE INVERSION PRESENT. MORE SUNSHINE TO START THE DAY AND THE
BEGINNING OF A WARMING TREND AT 850 MB WILL ALLOW TEMPERATURES TO
WARM SEVERAL DEGREES FROM SATURDAYS HIGHS. TONIGHT INTO MONDAY
MORNING A NORTHERLY GRADIENT WILL DEVELOP AT THE SURFACE AND IN THE
THE LOWER LEVELS WITH LIGHT NORTH/NORTHEAST WINDS DEVELOPING IN THE
NORTH BAY HILLS. EXPECT WARMER TEMPERATURES TONIGHT IN THE HILLS AS
850 MB TEMPS TREND UPWARD. HOWEVER UNDER MOSTLY CLEAR SKIES TEMPS MAY
COOL IN THE VALLEYS GIVEN BETTER RADIATION. WARMING TREND THEN
CONTINUES INTO MONDAY AND TUESDAY WITH THE GRIDS ATTEMPTING TO
REFLECT A PERIOD OF ABOVE NORMAL TEMPERATURES FOR MOST OF THE CWA.
MOSTLY CLEAR SKIES SHOULD CONTINUE AT LEAST THROUGH MIDWEEK AND
LIKELY INTO THURSDAY WITH 850 MB TEMPS PEAKING AROUND 22-23 DEGREES
CELSIUS BY WEDS OR THURSDAY DEPENDING ON MODEL SELECTION. THIS
SHOULD LEAD TO WIDESPREAD READINGS INTO THE 80S AND LOWER 90S FOR
INLAND AREAS WITH 70S EVEN NEAR THE COAST.
BY FRIDAY THE FORECAST CONFIDENCE DECREASES DRAMATICALLY. THE 00Z
ECMWF STARTS TO BUILD A FAIRLY STRONG RIDGE THROUGH MOST OF THE
7-10 DAY TIME FRAME WHICH IS A CHANGE OF SOLUTIONS FROM PREVIOUS
DAYS. THE GFS BRINGS A WEAK TROUGH INTO THE AREA BY FRIDAY AND INTO
THE WEEKEND WHICH WOULD LEAD TO INCREASED CLOUD COVER AND COOLER
TEMPS. FOR THE MOST PART MADE LITTLE CHANGE TO THE EXTENDED AND WILL
LEAN TOWARDS CLIMO UNTIL BETTER MODEL AGREEMENT ENSUES.
&&
.AVIATION...AS OF 4:00 AM PDT SUNDAY...COMING SOON.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ALL WATERS EXCEPT MRY BAY.
$$
PUBLIC FORECAST: RW
AVIATION/MARINE: PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSTO 211032
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 AM PDT SUN SEP 21 2008
.DISCUSSION...
SHORTWAVE RIDGING OVERHEAD NORTHERN CALIFORNIA EARLY THIS MORNING
AHEAD OF NEXT SHORTWAVE TROUGH NOW INSIDE OF 130W. THIS FEATURE WILL
BRUSH ACROSS FAR NORTHERN CALIFORNIA LATE TODAY BRINGING A SLIGHT
CHANCE OF A FEW SHOWERS ACROSS THE FAR NORTHERN MOUNTAINS INTO EARLY
THIS EVENING AS IT PROVIDES SOME UPWARD VERTICAL MOTION TO ACT ON
WEAK INSTABILITY PRESENT ACROSS THE FAR NORTH.
TEMPERATURES TODAY ARE EXPECTED TO BE SLIGHTLY WARMER THAN SATURDAY
ACROSS MUCH OF THE REGION AS THE ONSHORE GRADIENT OF THE PAST FEW
DAYS HAS SLACKENED OFF CONSIDERABLY. WARMING IS EXPECTED TO CONTINUE
MONDAY AS DRIER NORTHERLY FLOW DEVELOPS THROUGH THE BOUNDARY LAYER
BEHIND THIS AFTERNOON/S SHORTWAVE AND THE AIRMASS WARMS IN RESPONSE
TO RISING HEIGHTS ALOFT.
COOL NIGHTS WILL BE ON TAP ACROSS THE REGION THIS WEEK WITH THE
AIRMASS DRYING MONDAY. ALONG WITH GENERALLY CLEAR SKIES...THIS WILL
RESULT IN BETTER RADIATIONAL COOLING ALLOWING SOME OF THE HIGHER
MOUNTAIN VALLEYS TO ONCE AGAIN DIP DOWN TO NEAR THE FREEZING MARK.
ABOVE NORMAL DAYTIME TEMPERATURES AND COOL NIGHTS IN THE VALLEYS
WILL CONTINUE THE SECOND HALF OF THE WEEK AS THE SOUTHWEST UPPER
HIGH IS FORECAST TO BUILD NORTHWARD PUSHING THE STORM TRACK BACK
WELL TO THE NORTH OF THE REGION.
&&
.AVIATION...
VFR CONDS. APPROACHING SHORT WAVE TDA WILL SPREAD HIGH BASED
CLOUDINESS OVER INTERIOR NORCAL...ESPECIALLY NRN MTNS WITH CHANCE OF
ISOLD RW-/TRW- IN THE AFTN.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSGX 211006
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
330 AM PDT SUN SEP 21 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. WEAK UPPER LEVEL LOW PRESSURE WILL KEEP MOST TEMPERATURES
BELOW SEASONAL AVERAGES THROUGH MONDAY. LOCALLY WINDY IN THE
MOUNTAINS AND DESERTS AT TIMES. WARMER DURING THE SECOND HALF THE
WEEK UNDER HIGH PRESSURE THEN COOLER AGAIN TOWARD NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A TROUGH OF LOW PRESSURE OVER THE WESTERN STATES CENTERED NEAR THE
PACIFIC NORTHWEST WILL BEGIN TO DEAMPLIFY TUESDAY. THIS TROUGH WILL
MAINTAIN COOLER THAN SEASONAL TEMPERATURES AND A MARINE LAYER DEPTH
NEAR 2000 FEET INTO MONDAY. SLOW WARMING AND A SLOW DECREASE IN
MARINE LAYER DEPTH IS EXPECTED FOR TUESDAY.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
HIGH PRESSURE WILL BUILD OVER THE SOUTHWEST STATES FOR THURSDAY AND
FRIDAY BRINGING WARMING TO ABOVE SEASONAL AVERAGES AND A SHALLOWER
MARINE LAYER. MID LEVEL MOISTURE IN SOUTH FLOW ALOFT MAY ALSO BRING
SOME AFTERNOON CLOUDS TO THE MOUNTAINS.
FOR FRIDAY AND SATURDAY...HIGH PRESSURE WILL SHIFT TO THE EAST AS A
WEAK TROUGH OF LOW PRESSURE DEVELOPS OFF THE WEST COAST. THIS WILL
BRING SLOW COOLING AND SLOW DEEPENING OF THE MARINE LAYER.
&&
.AVIATION...
211000Z...MARINE LAYER ABOUT 2500 FT. BASES AROUND 2K FT MSL. VSBY
ABOVE 7SM WITH LOCAL 3-5SM INLAND IN THE MORNING. STRATUS EXPECTED
TO CLEAR BY 17Z. STRATUS RETURNING LATE AFTERNOON. NOT MUCH CHANGE
EXPECTED THROUGH MONDAY AS ANOTHER TROUGH MOVES THROUGH TO THE NORTH
TODAY THROUGH MONDAY MORNING. A WEAK COASTAL EDDY IS FORECAST TO
CONTINUE THROUGH MONDAY MORNING. OTHERWISE CLEAR.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...WHITLOW
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS65 KREV 211006
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
300 AM PDT SUN SEP 21 2008
.SHORT TERM...
A WEAK SHORTWAVE TROUGH SEEN ON WATER VAPOR IMAGERY THIS
MORNING...IS APPROACHING THE NORTHERN CALIFORNIA COAST. THIS WAVE
WILL NOT HAVE VERY MUCH MOISTURE ASSOCIATED WITH IT...ALTHOUGH WITH
A FAVORABLE REGION OF THE UPPER LEVEL JET MOVING IN OVERHEAD THERE
REMAINS A SLIGHT CHANCE FOR A THUNDER SHOWER NORTH OF SUSANVILLE AND
GERLACH THIS EVENING. ANY SHOWERS THAT DO DEVELOP WILL MOVE EAST
INTO NORTHERN PERSHING COUNTY BEFORE MIDNIGHT. WINDS WILL INCREASE
IN THE AFTERNOON OUT OF THE WEST WITH GUSTS UP TO 25 TO 30 MPH.
AFTER THIS SHORTWAVE DEPARTS THE AREA...ZONAL FLOW WILL RETURN TO
THE AREA. WE SHOULD SEE AN INCREASE OF HEIGHTS AND TEMPERATURES
ALOFT...WITH SOME AFTERNOON WESTERLIES AND VALLEY TEMPS WARMING UP
SEVERAL DEGREES EACH DAY MON-TUES. HOON
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
FEW CHANGES MADE TO A PRECIPITATION-FREE FORECAST FOR THE EXTENDED
PERIOD. RIDGE OVER THE SOUTHWEST CONUS KEEPS SHORT WAVE ENERGY AND
ASSOCIATED MOISTURE AND PRECIPITATION NORTH OF NEVADA ON WEDNESDAY.
A STRONGER TROUGH APPROACHES THE WEST COAST BY FRIDAY...INITIALLY
DRAWING MID LEVEL MOISTURE INTO SOUTHERN AND EASTERN ZONES. WILL ADD
PARTLY CLOUDY SKIES TO MONO AND MINERAL COUNTIES ON FRIDAY BEFORE A
STRONGER SOUTHWEST FLOW PUSHES THAT MOISTURE EAST OF THE AREA ON
SATURDAY. TEMPERATURES REMAIN ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH 12Z MONDAY. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KLOX 211003
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
303 AM PDT SUN SEP 21 2008
.SHORT TERM (TODAY-WEDNESDAY)...MARINE LAYER IS PATCHY THIS
MORNING WITH WEAK INVERSION IN PLACE AND MARINE LAYER DEPTH
AROUND 1500 FEET. FORECAST HAS INCREASED MARINE LAYER PRESENCE IN
SAN FERNANDO VALLEYS BUT DECREASE STRATUS DEVELOPMENT IN THE
SALINAS RIVER VALLEY. OTHERWISE...PATCHY FORECAST SEEMS TO WORK
OUT FOR THIS MORNING WITH WEAK INVERSION IN PLACE. TEMPERATURES
WERE WARMED SLIGHTLY WITH WEAK MARINE INVERSION IN PLACE AND A
SLIGHT OFFSHORE TREND OCCURRING THIS MORNING.
GOOD AGREEMENT BETWEEN BOTH NAM AND GFS SOLUTIONS IN INDICATING
LITTLE CHANGE IN THE MARINE LAYER FOR TONIGHT AND MONDAY.
1000-500 MB THICKNESSES STAY ABOUT THE SAME IN BOTH MODELS. AREAL
COVERAGES SHOULD BE SIMILAR WITH MAYBE SLIGHT THICKENING IN THE
MARINE LAYER SOUTH OF POINT CONCEPTION. THIS WILL BE DUE TO AN
EDDY CIRCULATION OVER THE INNER WATERS.
TEMPERATURES COULD BE MIXED FOR MONDAY. 950 MB TEMPERATURES
WARM OVER THE AREA...BUT THICKNESSES STAY AROUND THE SAME.
SURFACE GRADIENTS TREND MORE ONSHORE SOUTH OF POINT CONCEPTION
AND TREND OFFSHORE NORTH OF POINT CONCEPTION. WITH WARMER SEA
SURFACE TEMPERATURES IN PLACE OVER THE INNER WATERS AND AT THE
BEACHES...FORECAST TRENDS SLIGHT WARMER...BUT A WELL-DEVELOPED
EDDY CIRCULATION COULD PUT THE DAMPER ON THE TREND.
1000-500 MB THICKNESSES AND 950 MB TEMPERATURES TREND UPWARD FOR
MIDWEEK WITH NEUTRAL TO OFFSHORE TRENDING SURFACE GRADIENTS.
MARINE LAYER WILL REMAIN OVER THE COASTAL SECTION...BUT A
DECREASING INFLUENCE IN COVERAGE AND DEPTH WILL LIKELY BRING
WARMER TEMPERATURES TO THE AREA FOR MIDWEEK.
.LONG TERM (THURSDAY-SATURDAY)...SOUTH TO SOUTHWEST FLOW ALOFT
WILL LIKELY REDEVELOP FOR LATE WEEK BRINGING AN INCREASE IN
MARINE LAYER MOISTURE. GFS SOLUTIONS COULD DEVELOP A EDDY
CIRCULATION OVER THE INNER WATERS WITH SOME LOCAL DRIZZLE
POSSIBLE...BUT ECMWF SOLUTIONS DOWNPLAY THE SCENARIO. AT THE VERY
LEAST...A COOLING TREND SHOULD DEVELOP FOR LATE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...21/0530Z.
MARINE LAYER ABOUT 1400 DEEP AND CAPPED BY A VERY WEAK INVERSION. A
WEAK EDDY WILL SPIN UP TONIGHT AND CIGS WILL LIKELY FORM FROM KLGB
TO KOXR AND CANNOT RULE OUT GETTING INTO KSBA (IN FACT THIS COULD BE
ONE OF THOSE TIMES WHERE KSBA GETS THE CIGS AFTER SUNRISE. CLOUDS
WILL BE MORE PATCHY IN THE VLYS. DUE TO WEAK INVERSION BURN OFF
SHOULD OCCUR NEAR MID MORNING.
KLAX...GOOD CONFIDENCE IN TAF CIGS WILL LIKELY ARRIVE WITH IN ONE
HOUR OF FCST TIME AND BURN OFF TIME IS ALSO LIKELY WITH THE SAME ONE
HOUR BLOCK.
KBUR...ONLY FAIR CONFIDENCE IN TAF. THERE IS A 40 PERCENT CHANCE OF
IFR CIGS AFTER 11Z. IF CIGS DO FORM THEY SHOULD DISSIPATE BY 16Z.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...HALL
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KHNX 211001
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
301 AM PDT SUN SEP 21 2008
.DISCUSSION...
COOL ZONAL FLOW ACROSS THE REGION TODAY WILL KEEP TEMPERATURES
SIMILAR TO YESTERDAYS VALUES. ANOTHER WEAK DISTURBANCE WILL CROSS
THE NRN CA REGION TODAY PROVIDING A REINFORCING SHOT OF COOL AIR
THIS AFTERNOON AND KEEP TEMPS IN LINE FOR MONDAY AS WELL. ONCE
THIS TROUGH PASSES BY...WE WILL THEN BEGIN TO SEE THE IMPACT OF A
BUILDING RIDGE ACROSS THE REGION BY WED AND CONTINUE THROUGH
FRIDAY. TEMPERATURES ARE EXPECTED TO CLIMB WELL ABOVE NORMAL AND
WE WILL ONCE AGAIN SEE THE POSSIBILITY OF HIGH TEMPERATURES ON
THURSDAY INTO THE MIDDLE TO UPPER 90S IN THE CENTRAL AND SOUTHERN
SAN JOAQUIN VALLEY AS WELL AS THE KERN COUNTY DESERT REGION.
SINCE THE WESTERLIES ARE BECOMING MORE ACTIVE AND ARE TRYING TO
MOVE FARTHER SOUTH...WE WILL ONCE AGAIN SEE A DEEPENING LONG WAVE
TROUGH MOVE INTO THE EPAC FROM THE CENTRAL PAC BY FRIDAY AND WILL
IMPACT OUR AREA BY LOWERING TEMPS BACK DOWN TO NEAR OR JUST BELOW
NORMAL VALUES BY FRIDAY AND CONTINUING THROUGH NEXT WEEKEND. IT
IS EXPECTED TO REMAIN DRY THROUGH THE ENTIRE FORECAST PERIOD.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA
INTERIOR THROUGH 12Z MONDAY.
&&
.AIR QUALITY ISSUES...
ON SUNDAY SEPTEMBER 21 2008... UNHEALTHY FOR SENSITIVE GROUPS IN
KERN COUNTY.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JDB
AVN/FW...DCH
WEATHER.GOV/HANFORD
000
FXUS65 KPSR 210840
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
140 AM MST SUN SEP 21 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN TODAY. OTHERWISE
...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT SOUTHWEST
THE NEXT COUPLE DAYS...AS AN AREA OF LOW PRESSURE PASSES TO THE
NORTH. DRY CONDITIONS WILL CONTINUE THIS WEEK...UNDER MOSTLY CLEAR
SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
SAT IMAGERY EARLY THIS MORNING SHOWS MOSTLY CLEAR/CLEAR SKIES OVER
SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA. 24 HR
CHANGE PRODUCT INDICATES SFC DEW POINTS FROM THE CO RIVER WESTWARD
ARE RUNNING 15-20 DEG LOWER THAN THIS TIME YESTERDAY. THE DRIER
CONDITIONS AND CLEAR SKIES WILL ALLOW FOR MAXIMUM RADIATIONAL
COOLING OVERNIGHT...WITH THIS MORNING/S LOWS OUT WEST RUNNING 4-7
DEG COOLER THAN SATURDAY MORNING. NOT AS MUCH DRYING OVER THE LOWER
SOUTH-CENTRAL ARIZONA DESERTS...AND CURRENT IR SAT TRENDS EVEN SHOW
A FEW LOW LEVEL CLOUDS OVER PORTIONS OF NORTHWESTERN PINAL AND
SOUTHERN GILA COUNTY. THE KSPR 00 UTC SUN SOUNDING FROM EARLIER
INDICATES AN INCREASE IN MOISTURE (OVER 24 HOURS AGO) WITH A FAIRLY
MOIST LAYER BETWEEN 800-750MB (AROUND 8K-15K FT). WITH THE LINGERING
MID LEVEL MOISTURE IN PLACE...THE INHERITED SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN EAST OF
PHOENIX...OVER PORTIONS OF SOUTHERN GILA COUNTY...FOR THIS
AFTERNOON/EARLY EVENING LOOKS GOOD. ELSEWHERE...A DRY FORECAST
REMAIN IN PLACE. AS FOR TEMPS...THE FLAT RIDGE (IN RESPONSE TO THE
TROUGH MOVING BY WELL TO THE NORTH) WILL RESULT IN LITTLE CHANGE IN
HIGH TEMPS TODAY WITH THE WARMEST DESERT LOCALES AROUND 100 DEG.
MONDAY THROUGH THE REST OF THE WEEK...THE MORE POTENT LOW MOVING
THROUGH THE PAC NW/NRN ROCKIES THIS WEEKEND WILL GIVE WAY TO A BROAD
TROUGH OVER MUCH OF THE WESTERN CONUS MON/TUES. AS IT DOES SO...THE
LARGE ANTI-CYCLONE (PROGGED BY THE MODELS FOR THE PAST SEVERAL RUNS)
WILL BUILD OVER THE GREATER SOUTHWEST. EVEN WITH THE HIGH IN PLACE
THE MID TO LATTER PART OF THE WEEK...MODELS ARE NOT INDICATING MUCH
OF AN INCREASE IN THICKNESS/500MB HEIGHTS...SO DO NOT EXPECT MUCH
DAY TO DAY CHANGE IN TEMPS. MEANWHILE...SKIES WILL REMAIN MOSTLY
CLEAR...WITH A FEW AFTERNOON CU POSSIBLE OVER THE HIGHER TERRAIN TO
THE EAST. WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS...WITH WESTERLY
BREEZES/GUSTS AROUND 15-20 MPH AT TIMES DURING PEAK HEATING EACH DAY
THIS UPCOMING WEEK.
&&
.AVIATION...
MOSTLY CLEAR SKIES ARE EXPECTED OVERNIGHT AND THROUGH MID-DAY ON
SUNDAY. SOME RESIDUAL LOW LEVEL MOISTURE WILL REMAIN ON SUNDAY. THIS
WILL ENABLE SCATTERED TO BROKEN CUMULUS CLOUDS TO FORM ONCE AGAIN IN
EAST CENTRAL ARIZONA DURING THE AFTERNOON AND EARLY EVENING...WITH
CLOUD BASES RANGING FROM AROUND 090 TO 120 KFT. SKIES WILL REMAIN
MOSTLY CLEAR WEST OF THE COLORADO RIVER.
WINDS AT KPHX AND KIWA WILL BE LIGHT OUT OF THE SOUTHWEST TO WEST
THROUGH EARLY MORNING...WHEN THE NORMAL DIURNAL SHIFT TO A MORE
SOUTHEAST DIRECTION OCCURS. WINDS AT KYUM...KIPL...AND KBLH WILL BE
5 TO 10 KT OUT OF THE WEST TO SOUTHWEST...WITH WINDSPEEDS PICKING UP
SLIGHTLY SUNDAY AFTERNOON AND EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...MCLANE
FIRE WEATHER...SIPPLE
000
FXUS66 KMTR 210531
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1030 PM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 8:30 PM PDT SATURDAY...TWO RECORDS WERE SET TODAY
AT SAN JOSE INTERNATIONAL AIRPORT AND SALINAS AIRPORT. ODDLY ENOUGH
IT WAS FOR RECORD RAINFALL WHICH IS UNUSUAL FOR THIS TIME OF YEAR.
SAN JOSE RECEIVED A TRACE OF RAIN BREAKING ITS PREVIOUS RECORD
FOR THE DAY OF 0.00 INCHES FROM RECORDS DATING BACK TO 1947 WHILE
SALINAS RECORDED ONE HUNDREDTH OF AN INCH TYING ITS RECORD SET BACK
IN 1973. NEEDLESS TO SAY VERY MOIST CONDITIONS EXISTED ACROSS THE
REGION THIS MORNING WITH EXTENSIVE LOW CLOUDS AND RECORDED RAINFALL
IN VARIOUS LOCATIONS. MANY LOCATIONS ACROSS THE DISTRICT SAW
TEMPERATURES UP TO FIVE DEGREES COOLER THAN YESTERDAY AS A RESULT OF
LOW LEVEL CLOUDS THAT LINGERED WELL INTO THE AFTERNOON IN SOME
AREAS.
SATELLITE IMAGERY SHOWS A LARGE PATCH OF STRATUS MOVING SOUTH ALONG
THE COAST THIS EVENING. AN INCREASING NORTHERLY GRADIENT WILL MOVE
THIS AREA OF STRATUS DOWN THE CENTRAL COAST OVERNIGHT. ALTHOUGH THIS
SWATH OF LOW CLOUDS WILL KEEP AREAS ALONG THE COAST MOIST OVERNIGHT
AND INTO SUNDAY DRIER CONDITIONS ARE IN-STORE FOR THE INLAND AREAS.
A WEAK UPPER LEVEL TROUGH IS SLATED TO SWINGS ACROSS THE NORTHERNMOST
PART OF THE STATE SUNDAY AFTERNOON KEEPING THE BOUNDARY LAYER MIXED
OUT AND THE MARINE LAYER FROM BEING ABLE TO REDEVELOPING. HIGH
PRESSURE WILL BEGIN MOVING IN OVER THE PACIFIC NORTHWEST ON SUNDAY
USHERING IN A WARMER AND DRIER AIRMASS WITH IT. THIS WILL GREATLY
IMPACT THE FORMATION OF STRATUS AND RESULT IN A WARMER TEMPERATURES
BEGINNING ON MONDAY.
FROM PREVIOUS DISCUSSION...THE MODELS MAINTAIN A NEARLY ZONAL UPPER
LEVEL FLOW ACROSS CA WITH RELATIVELY HIGH HEIGHTS THROUGH MOST OF
NEXT WEEK. TEMPERATURES SHOULD WARM TO NEAR NORMAL ON MONDAY AND THEN
REMAIN AT OR SLIGHTLY ABOVE NORMAL FOR THE REMAINDER OF THE WEEK. A
TROUGH MOVING INTO THE PAC NW AROUND MIDWEEK LOOKS AS THOUGH IT WILL
BE TOO FAR NORTH TO HAVE MUCH IMPACT ON OUR WEATHER. TOUGH TO SAY
WHEN A MARINE LAYER MIGHT REDEVELOP...BUT MOST LIKELY SCENARIO IS
AROUND MIDWEEK WHEN THE UPPER TROUGH MOVES INLAND TO OUR NORTH AND
TRIGGERS A SLIGHT INCREASE IN ONSHORE FLOW. THE MEDIUM RANGE MODELS
AGREE THAT A WEAK CUTOFF LOW WELL WEST OF BAJA WILL EJECT TO THE NE
LATE IN THE WEEK AND MOVE INLAND ACROSS CA BY LATE FRIDAY OR
SATURDAY. STILL TOO EARLY TO SAY IF THIS WILL HAVE MUCH OF AN IMPACT
ON OUR WEATHER...BUT MOISTURE WITH THIS UPPER LOW IS FORECAST TO BE
LACKING AND SO RAIN CHANCES ARE NO WHERE IN SIGHT AT THIS TIME.
&&
.AVIATION...AS OF 10:30 PM PDT SATURDAY...TEMPERATURES AND DEWPOINTS
ARE DECLINING WHICH INDICATES A DRYING TREND IS UNDERWAY. HOWEVER
NIGHT-TIME COOLING WILL OFFSET THIS A BIT AND ALLOW STRATUS TO
REDEVELOP. OVERALL COVERAGE MAY BE LIMITED OVERNIGHT. AT THE MOMENT
SATELLITE SHOWS A FEW AREAS OF STRATUS MOSTLY OUT OVER THE COASTAL
WATERS. AREAS OF IFR CEILINGS ARE STILL EXPECTED OVERNIGHT. THE
MODELS SHOW THE LOW LEVEL WINDS VEERING MORE TO THE NORTH WHICH
INDUCES A DRYING EFFECT BUT ITS IMPACT WILL LIKELY HOLD OFF UNTIL
SUNDAY MORNING WHEN IT COMBINES WITH DAYTIME WARMING. VFR IS FORECAST
SUNDAY. LOCALLY GUSTY AFTERNOON AND EVENING WINDS ARE POSSIBLE SUNDAY
AS THE MODELS SHOW AN INCREASE IN ONSHORE PRESSURE GRADIENTS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
$$
PUBLIC FORECAST: C WALBRUN
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 210530
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1020 PM PDT SAT SEP 20 2008
UPDATED AVIATION DISCUSSION
.SHORT TERM (TODAY-TUESDAY)...
AS EXPECTED...TEMPS WERE COOLER JUST ABOUT EVERYWHERE TODAY AS 950
MB TEMPS COOLED NEARLY 5 DEGREES FRIDAY NIGHT INTO TODAY. SOME
LINGERING HIGHER RH VALUES ACROSS THE SAN JOAQUIN VALLEY AND DECENT
NRN GRADIENTS WILL HELP TO PUSH SOME CLOUDS INTO THE NRN SLOPES OF
SBA/VTU AND WESTERN LA COUNTY MTNS OVERNIGHT. THERE COULD BE SOME
LOCALLY DENSE FOG POSSIBLE ACROSS THE GRAPEVINE AFTER MIDNIGHT.
ALSO...EXPECT SOME LOCALLY GUSTY WINDS ACROSS THE I-5 CORRIDOR WITH
NORTHWEST TO NORTH WINDS 20 TO 30 MPH WITH GUSTS TO 40 MPH POSSIBLE
OVERNIGHT. THE SANTA BARBARA COUNTY MTNS AND ADJACENT SOUTH COAST
WILL EXPERIENCE GUSTY NORTHWEST TO NORTH WINDS THIS
EVENING...SHIFTING TO THE NORTHEAST LATER THIS EVENING. THIS WILL
CONTINUE TO AFFECT THE PASSES AND CANYONS NEAR GAVIOTA AND LAS
FLORES CANYON WITH GUSTS TO 40 MPH...THEN SHIFT THE FOCUS ON THE
FOOTHILLS ABOVE MONTECITO LATER TONIGHT. PORTIONS OF THE ANTELOPE
VALLEY WILL CONTINUE SW TO W WINDS 20 TO 30 MPH WITH LOCAL GUSTS TO
45 MPH...MAINLY NEAR THE SOLEDAD CYN PASS AND LAKE PALMDALE THIS
EVENING.
NOT MUCH CHANGE IN THE UPPER PATTERN AS BROAD NW FLOW WILL PERSIST
THROUGH SUNDAY. HOWEVER...A FAIRLY SIGNIFICANT EDDY BEGINS TO
DEVELOP OVERNIGHT AS MODERATE NW FLOW ACROSS THE OUTER WATERS
PERSISTS. LOW CLOUDS SHOULD BE BETTER ORGANIZED TO AFFECT THE LA
COUNTY COASTAL AREAS...POSSIBLY MAKING INTO VTU COUNTY COASTAL AREAS
LATE. LATEST SATELLITE IMAGERY DOES SHOW A MORE ORGANIZED AREA OF
STRATUS MOVING UP INTO ORANGE COUNTY AND SHOULD REACH LA COUNTY BY
MIDNIGHT. PRETTY GOOD CONFIDENCE THAT LOW CLOUDS SHOULD STAY OUT OF
SBA COUNTY SOUTH COAST DUE TO THE NORTHERLY GRADS THIS EVENING.
LATEST AMDAR SOUNDING NEAR KLAX SHOWS MARINE LAYER NEAR 1500
FT...BUT INVERSION REMAINS QUITE WEAK DUE TO COOLER AIR ADVECTION
EARLIER. THE CENTRAL COAST SHOULD SEE SOME PATCHY LOW CLOUDS
DEVELOP...ESPECIALLY BETWEEN LOMPOC AND SANTA MARIA...BUT NOT QUITE
AS ORGANIZED AS TO THE SOUTH AS SATELLITE IMAGERY INDICATES.
TEMPS SHOULD A BIT WARMER THEN WHAT MOS GUIDANCE WAS ADVERTISING N
OF POINT CONCEPTION DUE TO WEAK OFFSHORE FLOW FORECAST IN THE
MORNING. NOT MUCH CHANGE EXPECTED FOR THE COASTAL AREAS OF LA/VTU
COUNTIES...BUT TEMPS SHOULD REBOUND A COUPLE OF DEGREES ACROSS
INLAND AREAS.
HIGH PRESSURE ALOFT WILL BEGIN TO BUILD IN FROM THE SOUTH SLOWLY ON
MONDAY...AND STRENGTHEN TO A 590 DM HIGH BY EARLY TUE.
THEREFORE...TEMPS WILL BEGIN TO WARM UP BOTH DAYS...ESPECIALLY TUE.
SFC GRADS WHICH LOOKED TO BE LIGHTLY TO MODERATE OFFSHORE A FEW DAYS
AGO...NOW LOOKS MORE WEAKLY NEUTRAL. NEVERTHELESS...THIS SHOULD HELP
TEMPS TO WARM UP INTO THE LOWER 90S ACROSS THE WARMEST INTERIOR
LOCATIONS OF THE FORECAST AREA.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (WEDNESDAY-SATURDAY)...
WITH ONSHORE GRADS WEAKENING AND THE RIDGE CONTINUING ITS BUILD UP
FROM THE SOUTH...WED AND THU LOOKS TO REMAIN WARM...WITH ONE OF
THOSE DAYS BEING THE WARMEST OF THE WEEK. THE HIGH AND WEAK ONSHORE
GRADS SHOULD KEEP THE MARINE LAYER CONFINED TO THE IMMEDIATE COAST
AT BEST...WHICH FURTHER HINTS AT A WARM MIDWEEK. THERE IS A WILDCARD
IN A WEAK CUTOFF LOW TO THE WEST. THIS PATTERN WILL CREATE AN
EAST-WEST TEMP GRAD THAT MODELS CURRENTLY HAVE US SITTING IN THE
WARM SECTOR WED AND THU...BUT THIS PATTERN COULD SHIFT AND TEMPS
COULD BE A BIT COOLER. NOT ONLY THAT...BUT A WHEN QUESTION EXISTS AS
WELL...AS TO WHEN WILL THINGS FINALLY SHIFT TO THE EAST. CURRENTLY
THE GFS AND ECMWF ARE BEHAVING NICELY...WITH A TROUGH DIGGING INTO
THE LOW TO THE WEST AND PUSHING EVERYTHING EASTWARD ON FRI AND SAT.
THIS IS REFLECTED IN THE FORECAST WITH SOME COOLING...BUT CONFIDENCE
IS LOW THIS FAR OUT.
&&
.AVIATION...
21/0530Z.
MARINE LAYER ABOUT 1400 DEEP AND CAPPED BY A VERY WEAK INVERSION. A
WEAK EDDY WILL SPIN UP TONIGHT AND CIGS WILL LIKELY FORM FROM KLGB
TO KOXR AND CANNOT RULE OUT GETTING INTO KSBA (IN FACT THIS COULD BE
ONE OF THOSE TIMES WHERE KSBA GETS THE CIGS AFTER SUNRISE. CLOUDS
WILL BE MORE PATCHY IN THE VLYS. DUE TO WEAK INVERSION BURN OFF
SHOULD OCCUR NEAR MID MORNING.
KLAX...GOOD CONFIDENCE IN TAF CIGS WILL LIKELY ARRIVE WITH IN ONE
HOUR OF FCST TIME AND BURN OFF TIME IS ALSO LIKELY WITH THE SAME ONE
HOUR BLOCK.
KBUR...ONLY FAIR CONFIDENCE IN TAF. THERE IS A 40 PERCENT CHANCE OF
IFR CIGS AFTER 11Z. IF CIGS DO FORM THEY SHOULD DISSIPATE BY 16Z.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KAPLAN/KITTELL
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 210517
AFDPSR
AREA FORECAST DISCUSSION...AVIATION SECTION UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1017 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...SHORT-TERM DISCUSSION AND AVIATION SECTION UPDATED.
&&
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN SUNDAY.
OTHERWISE...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT
SOUTHWEST THE NEXT COUPLE DAYS AS AN AREA OF LOW PRESSURE PASSES TO
THE NORTH. DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY
CLEAR SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
DRIER AIR HAS MOVED INTO OUR FORECAST AREA WEST OF THE COLORADO
RIVER. DEWPOINTS IN THE REGION AT 04Z WERE RUNNING 10 TO 20 DEGREES
LOWER THAN THEY WERE THE SAME TIME LAST EVENING. THIS...ALONG WITH
THE CLEAR SKIES IN THE REGION...HAS RESULTED IN MORE RADIATIONAL
COOLING...ALLOWING TEMPERATURES TO DROP SEVERAL DEGREES COOLER THAN
FORECAST IN OUR AFTERNOON PACKAGE. THEREFORE HAD TO MAKE SOME
ADJUSTMENTS TO BOTH DEWPOINTS AND MIN TEMPERATURES THROUGH THE
REMAINDER OF THE FIRST PERIOD. ALSO MADE SOME MINOR TWEAKS TO OUR
WIND GRIDS.
THE GFS...NAM...AND RUC ALL WORK THE DRIER AIR A LITTLE FURTHER EAST
THROUGH MID-DAY ON SUNDAY...BUT KEEP A MOISTER BOUNDARY LAYER IN
PLACE OVER THE EASTERN HALF OF OUR FORECAST AREA. THE PSR 00Z
SOUNDING WAS VERY DRY FROM THE SURFACE TO 700 MB...WITH A MOISTER
LAYER ABOVE THAT...ROUGHLY BETWEEN 700 AND 600 MB. ALTHOUGH THERE
WAS PLENTY OF CUMULUS ACROSS EASTERN ARIZONA THIS AFTERNOON...A WARM
LAYER BETWEEN 575 AND 500 MB PROVIDED ENOUGH OF A CAP TO SUPPRESS
ALL BUT SOME VERY ISOLATED CELL DEVELOPMENT. MODELS INDICATE AN
INVERSION WILL ALSO BE IN PLACE TOMORROW...SO DESPITE A SLIGHT
INCREASE IN PRECIPITABLE WATER DURING THE PAST 24-HOURS...0.9 TO
1.26 INCHES...DO NOT EXPECT ANY ACTIVITY IN THE VALLEYS TOMORROW.
SOME LOW POPS IN THE HIGHER TERRAIN IN ZONE 24 THOUGH LOOKS
GOOD...AS AN ISOLATED STORM OR TWO COULD DEVELOP THERE.
&&
.PREV DISCUSSION...
ISSUED AT 701 PM MST SAT SEP 20 2008
QUICK UPDATE TO TAKE POPS OUT OF THE FIRST PERIOD. A CELL TRIED TO
DEVELOP SOUTHEAST OF GILA BEND AND ANOTHER ONE DEVELOPED SOUTH OF
CASA GRANDE....HOWEVER HAVE SINCE DISSIPATED. THESE WERE OVER
UNPOPULATED AREAS...WERE SHORT LIVED...HAD NO LIGHTNING...AND LIKELY
PRODUCED LITTLE IF ANY RAINFALL. SATELLITE SHOWS THAT ALL THAT
REMAINS IS A LITTLE CLOUDINESS IN SOUTHEAST MARICOPA...CENTRAL PINAL
AND SOUTHERN GILA COUNTIES. NOW THAT THE SUN HAS SET...EXPECT
REMAINING CLOUDS TO BEGIN THINNING OUT...LEAVING MOSTLY CLEAR SKIES
OVER THE ENTIRE FORECAST AREA.
ISSUED AT 250 PM MST SAT SEP 20 2008
WITH IMPROVED MOISTURE PROGGED OVER ZONE 24 FOR SUNDAY...NUDGED UP
POPS THERE OVER THE MOUNTAINS A LITTLE BIT. ON MONDAY...AN OPEN WAVE
TROUGH TAKES THE PLACE OF THE LOW CURRENTLY MOVING THROUGH THE
INTERIOR NORTHWEST. THIS WILL HELP ADVANCE THE DRIER AIR ALREADY
OVER WESTERN PORTIONS OF THE FORECAST AREA INTO SOUTH-CENTRAL
ARIZONA. THESE FEATURES WILL ALSO HELP TO KEEP THE RIDGE A FLAT IN
PLACE WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. THEREAFTER...A RIDGE
BEGINS BUILDING OVER THE DESERT SOUTHWEST...THOUGH HEIGHTS DONT
APPEAR TO SHOOT UP TOO HIGH. WITH THE WESTERLIES WAXING AND WANING
LOCALLY BREEZY TO WINDY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY
IN SOUTHEAST CALIFORNIA.
WEDNESDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
MOSTLY CLEAR SKIES ARE EXPECTED OVERNIGHT AND THROUGH MID-DAY ON
SUNDAY. SOME RESIDUAL LOW LEVEL MOISTURE WILL REMAIN ON SUNDAY. THIS
WILL ENABLE SCATTERED TO BROKEN CUMULUS CLOUDS TO FORM ONCE AGAIN IN
EAST CENTRAL ARIZONA DURING THE AFTERNOON AND EARLY EVENING...WITH
CLOUD BASES RANGING FROM AROUND 090 TO 120 KFT. SKIES WILL REMAIN
MOSTLY CLEAR WEST OF THE COLORADO RIVER.
WINDS AT KPHX AND KIWA WILL BE LIGHT OUT OF THE SOUTHWEST TO WEST
THROUGH EARLY MORNING...WHEN THE NORMAL DIURNAL SHIFT TO A MORE
SOUTHEAST DIRECTION OCCURS. WINDS AT KYUM...KIPL...AND KBLH WILL BE
5 TO 10 KT OUT OF THE WEST TO SOUTHWEST...WITH WINDSPEEDS PICKING UP
SLIGHTLY SUNDAY AFTERNOON AND EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/AJ
AVIATION...MCLANE
FIRE WEATHER...SIPPLE
000
FXUS66 KSTO 210507
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
955 PM PDT SAT SEP 20 2008
.DISCUSSION...
SHORT WAVE THAT HAS MOVED OVER NORCAL TODAY MAINTAINED ONSHORE FLOW
AND BROUGHT COOLER THAN NORMAL MAX TEMPS TO THE INTERIOR...SOME 8 TO
10 DEG BELOW NORMAL IN THE VLY. UPWARD MOTION FROM THE SHORT WAVE
HAS LIFTED/ERODED MUCH OF THE MARINE LAYER ALONG THE CA COAST...
EXCEPT INTO AND NEAR THE SFO BAY AREA. WITH WATER VAPOR AND MODELS
INDICATING RELATIVELY WEAK SHORT WAVES OVER THE ERN PAC MOVING
ACROSS NORCAL ON SUN...WE EXPECT ONSHORE FLOW TO CONTINUE WITH THE
MARINE LAYER OFF THE SFO COAST CONTINUING TO PROVIDE MUCH COOLER
THAN NORMAL MAX TEMPS THROUGH THE DELTA INFLUENCE AREAS. LOOKS LIKE
FURTHER AWAY FROM THE MARINE INFLUENCE MOST SITES SHOULD SEE SOME
WARMING ON SUN BASED ON THE FORECAST 850 MBS TEMPS AND LOW TO MID
LEVEL THICKNESSES...PERHAPS 2 TO 6 DEG OF WARMING. CLOUDINESS ALONG
AND N OF 40N EXPECTED TO SPREAD INLAND ACROSS THE NRN ZONES ON SUN
WITH WEAK INSTABILITY NOTED ACROSS THE NRN MTNS AND NE PLATEAU.
THERE IS SOME UPPER LEVEL DIVERGENCE NOTED ACROSS THE AREA FROM THE
INDIRECT CIRCULATION OF THE INBOUND JET SUN AFTN.
THE SHORT WAVES CONSOLIDATE AS THE TROF DEEPENS SLIGHTLY AS IT MOVES
INTO THE GREAT BASIN ALLOWING THE ERN PAC RIDGE TO BUILD INTO NORCAL
SLIGHTLY ON MON. ADDITIONAL WARMING OF SOME 4 TO 6 DEG IS EXPECTED
BASED ON THE FORECAST 850 MBS TEMPS AND LOW TO MID LEVEL
THICKNESSES. SO THE FIRST DAY OF FALL WILL STILL SEEM A LITTLE
SUMMERY...AS THE AUTUMNAL EQUINOX OCCURS ON 9/22 AT 1544Z (0844
PDT). ADDITIONAL WARMING EXPECTED ON TUE WITH TEMPS RETURNING TO
NORMAL AS THE RIDGE OF HIGH PRESSURE FROM THE DESERT SW EXPANDS
SLIGHTLY NWD. JHM
&&
.EXTENDED DISCUSSION (TUESDAY NIGHT THROUGH SATURDAY)...
HI PRESSURE DEVELOPS NEAR THE MEXICO BORDER IN THE DESERT SOUTHWEST
AS 500 MB HEIGHTS BECOME ZONAL ACROSS NORTHERN CALIFORNIA. SOME WEAK
SHORTWAVES MAY PASS TO THE NORTH OF CALIFORNIA WEDNESDAY THROUGH
FRIDAY. TEMPERATURES ARE EXPECTED TO FLUCTUATE NEAR NORMAL WITH
THURSDAY AND FRIDAY BEING THE WARMEST DAYS AS RIDGING EXPANDS
NORTHWARD...GENERALLY 2-4 DEGREES ABOVE NORMAL. TEMPS WILL BEGIN A
COOLING TREND...JUST BELOW NORMAL...BY SATURDAY AS A LOW PRESSURE
SYSTEM APPROACHES THE CANADIAN COASTLINE AND ITS ASSOCIATED TROUGH
DIGS SOUTHWARD OVER CALIFORNIA. HAVE KEPT FORECAST DRY DURING TROUGH
PASSAGE SINCE MODELS SHOW PRECIPITATION STAYING TO THE NORTH OR
ALONG THE COAST. JBB
&&
.AVIATION...
VFR CONDS WITH STRATUS EXPANDING OVER SFO BAY AREA WITH IFR/MVFR
CIGS. APPROACHING SHORT WAVE ON SUN WILL SPREAD HIGH BASED
CLOUDINESS OVER INTERIOR NORCAL...ESPECIALLY NRN MTNS ON SUN WITH
CHANCE OF ISOLD RW-/TRW- SUN AFTN.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 210444
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
944 PM PDT SAT SEP 20 2008
.UPDATE...UPPER TROF HAS EXITED THE REGION WITH NEXT PAC NW
SHORTWAVE FOLLOWING QUICK ON ITS HEALS. THE SECOND TROF WILL PASS
THRU CENTRAL CA SUN AFTERNOON. EXPECT LITTLE IF ANY TEMP CHANGE
SUN OVER TODAYS MAX/S...SO ISSUED UPDATE TO LOWER FCST HIGHS A FEW
DEGS. FLAT RIDGING THEN CONTINUES INTO TUES WITH A SLIGHT RISE IN
H5 HEIGHTS AND H85 TEMPS. STRONG RIDGE BUILDS OVER THE DESERT SW
BY MID WEEK FOR GOOD WARMING WED AND THURS. RIDGE SLIDES FARTHER
OFF TO THE EAST BY THE END OF THE WEEK...SO TEMPS TRENDING DOWN A
BIT NEXT FRI/SAT.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA
INTERIOR THROUGH 06Z MONDAY.
&&
.AIR QUALITY ISSUES...
ON SUNDAY SEPTEMBER 21 2008... UNHEALTHY FOR SENSITIVE GROUPS IN
KERN COUNTY.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BINGHAM
AVN/FW...DS
WEATHER.GOV/HANFORD
000
FXUS66 KSGX 210331
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PDT SAT SEP 20 2008
.SYNOPSIS...THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF
COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND
MORNINGS...EXTENDING LOCALLY INLAND. WEAK UPPER LEVEL LOW PRESSURE
WILL KEEP MOST TEMPERATURES BELOW SEASONAL AVERAGES THROUGH MONDAY.
LOCALLY WINDY IN THE MOUNTAINS AND DESERTS AT TIMES. WARMER DURING
THE SECOND HALF THE WEEK UNDER HIGH PRESSURE THEN COOLER AGAIN
TOWARD NEXT WEEKEND.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-TUE)...SKIES WERE CLEAR THIS EVENING EXCEPT FOR
AREAS OF STRATUS PUSHING ONSHORE...MAINLY IN SAN DIEGO COUNTY. THE
00Z NKX SOUNDING HAD AN INVERSION BASED NEAR 2600 FT WITH DRY WLY
WINDS ALOFT. MODERATELY STRONG ONSHORE GRADIENTS WITH ABOUT 8 MB
SAN-IPL AND IT WAS LOCALLY BREEZY TO WINDY IN THE MOUNTAINS AND
DESERTS.
WEAK UPPER LEVEL LOW PRESSURE WILL SLOWLY SHIFT E WITH AN UPPER HIGH
DEVELOPING OVER THE SW BY TUE. THIS WILL KEEP MAX TEMPS ABOUT 3 TO
7 DEGREES BELOW SEASONAL AVERAGES IN MOST AREAS...ESPECIALLY W OF
THE MOUNTAINS. SLIGHTLY WARMER MON AS LOCAL HEIGHTS BEGIN TO RECOVER
AND THEN MORE WARMING ON TUE. THE MARINE LAYER WILL BE DEEP ENOUGH
FOR LOW CLOUDS AND FOG IN THE COASTAL AREAS AND MOST SAN DIEGO
INLAND VALLEYS TONIGHT. THE MARINE LAYER WILL BECOME A LITTLE
SHALLOWER SUN AND MON NIGHTS. THE LOCALLY WINDY CONDITIONS IN THE
MOUNTAINS AND DESERTS WILL DECREASE AFTER TONIGHT AS ONSHORE
GRADIENTS AND WINDS ALOFT WEAKEN. OTHERWISE...FAIR IN DRY WLY FLOW
ALOFT.
&&
.LONG TERM (WED-SAT)...THE HIGH ALOFT WILL CONTINUE THE WARMING
TREND INTO THU WITH MAX TEMPS INLAND BECOMING ABOUT 4 TO 8 DEGREES
ABOVE SEASONAL AVERAGES INLAND. TEMPS WILL BE CLOSER TO SEASONAL
NEAR THE COAST. SLY FLOW WILL BRING IN LIMITED MID LEVEL MOISTURE
FOR A FEW CU OVER THE MOUNTAINS MID WEEK...BUT THUNDERSTORMS ARE NOT
EXPECTED AT THIS TIME. GRADUALLY COOLING WITH A DEEPENING MARINE
LAYER FRI AND SAT AS THE HIGH SHIFTS E AND AN UPPER LOW MOVES IN
FROM THE NW.
&&
.AVIATION...
210300Z...CLOUD BASES THIS EVENING WERE 2000 FEET MSL WITH A MARINE
LAYER DEPTH TO 2500 FEET. A COASTAL EDDY WILL MAINTAIN THE MARINE
LAYER DEPTH OVERNIGHT AND THE STRATUS FIELD OVER COASTAL AREAS WILL
SPREAD 20-25 MILES INLAND BY 12Z SUNDAY. THE STRATUS IS FCST TO
REMAIN A FEW MILES WEST OF ONT...ALTHOUGH VIS RESTRICTIONS OF 4-5SM
IN HAZE ARE EXPECTED BETWEEN 13-17Z SUNDAY.
CEILINGS AT SNA...CRQ AND SAN WILL CLEAR BY 18Z SUNDAY. SCT-BKN
STRATUS MAY LINGER OVER THE COASTAL WATERS AND BEACHES INTO THE
AFTERNOON.
ELSEWHERE...NO CIG/VIS RESTRICTIONS ARE EXPECTED ABOVE THE MARINE
LAYER.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...MOEDE
000
FXUS66 KLOX 210326
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
820 PM PDT SAT SEP 20 2008
.SHORT TERM (TODAY-TUESDAY)...
AS EXPECTED...TEMPS WERE COOLER JUST ABOUT EVERYWHERE TODAY AS 950
MB TEMPS COOLED NEARLY 5 DEGREES FRIDAY NIGHT INTO TODAY. SOME
LINGERING HIGHER RH VALUES ACROSS THE SAN JOAQUIN VALLEY AND DECENT
NRN GRADIENTS WILL HELP TO PUSH SOME CLOUDS INTO THE NRN SLOPES OF
SBA/VTU AND WESTERN LA COUNTY MTNS OVERNIGHT. THERE COULD BE SOME
LOCALLY DENSE FOG POSSIBLE ACROSS THE GRAPEVINE AFTER MIDNIGHT.
ALSO...EXPECT SOME LOCALLY GUSTY WINDS ACROSS THE I-5 CORRIDOR WITH
NORTHWEST TO NORTH WINDS 20 TO 30 MPH WITH GUSTS TO 40 MPH POSSIBLE
OVERNIGHT. THE SANTA BARBARA COUNTY MTNS AND ADJACENT SOUTH COAST
WILL EXPERIENCE GUSTY NORTHWEST TO NORTH WINDS THIS
EVENING...SHIFTING TO THE NORTHEAST LATER THIS EVENING. THIS WILL
CONTINUE TO AFFECT THE PASSES AND CANYONS NEAR GAVIOTA AND LAS
FLORES CANYON WITH GUSTS TO 40 MPH...THEN SHIFT THE FOCUS ON THE
FOOTHILLS ABOVE MONTECITO LATER TONIGHT. PORTIONS OF THE ANTELOPE
VALLEY WILL CONTINUE SW TO W WINDS 20 TO 30 MPH WITH LOCAL GUSTS TO
45 MPH...MAINLY NEAR THE SOLEDAD CYN PASS AND LAKE PALMDALE THIS
EVENING.
NOT MUCH CHANGE IN THE UPPER PATTERN AS BROAD NW FLOW WILL PERSIST
THROUGH SUNDAY. HOWEVER...A FAIRLY SIGNIFICANT EDDY BEGINS TO
DEVELOP OVERNIGHT AS MODERATE NW FLOW ACROSS THE OUTER WATERS
PERSISTS. LOW CLOUDS SHOULD BE BETTER ORGANIZED TO AFFECT THE LA
COUNTY COASTAL AREAS...POSSIBLY MAKING INTO VTU COUNTY COASTAL AREAS
LATE. LATEST SATELLITE IMAGERY DOES SHOW A MORE ORGANIZED AREA OF
STRATUS MOVING UP INTO ORANGE COUNTY AND SHOULD REACH LA COUNTY BY
MIDNIGHT. PRETTY GOOD CONFIDENCE THAT LOW CLOUDS SHOULD STAY OUT OF
SBA COUNTY SOUTH COAST DUE TO THE NORTHERLY GRADS THIS EVENING.
LATEST AMDAR SOUNDING NEAR KLAX SHOWS MARINE LAYER NEAR 1500
FT...BUT INVERSION REMAINS QUITE WEAK DUE TO COOLER AIR ADVECTION
EARLIER. THE CENTRAL COAST SHOULD SEE SOME PATCHY LOW CLOUDS
DEVELOP...ESPECIALLY BETWEEN LOMPOC AND SANTA MARIA...BUT NOT QUITE
AS ORGANIZED AS TO THE SOUTH AS SATELLITE IMAGERY INDICATES.
TEMPS SHOULD A BIT WARMER THEN WHAT MOS GUIDANCE WAS ADVERTISING N
OF POINT CONCEPTION DUE TO WEAK OFFSHORE FLOW FORECAST IN THE
MORNING. NOT MUCH CHANGE EXPECTED FOR THE COASTAL AREAS OF LA/VTU
COUNTIES...BUT TEMPS SHOULD REBOUND A COUPLE OF DEGREES ACROSS
INLAND AREAS.
HIGH PRESSURE ALOFT WILL BEGIN TO BUILD IN FROM THE SOUTH SLOWLY ON
MONDAY...AND STRENGTHEN TO A 590 DM HIGH BY EARLY TUE.
THEREFORE...TEMPS WILL BEGIN TO WARM UP BOTH DAYS...ESPECIALLY TUE.
SFC GRADS WHICH LOOKED TO BE LIGHTLY TO MODERATE OFFSHORE A FEW DAYS
AGO...NOW LOOKS MORE WEAKLY NEUTRAL. NEVERTHELESS...THIS SHOULD HELP
TEMPS TO WARM UP INTO THE LOWER 90S ACROSS THE WARMEST INTERIOR
LOCATIONS OF THE FORECAST AREA.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (WEDNESDAY-SATURDAY)...
WITH ONSHORE GRADS WEAKENING AND THE RIDGE CONTINUING ITS BUILD UP
FROM THE SOUTH...WED AND THU LOOKS TO REMAIN WARM...WITH ONE OF
THOSE DAYS BEING THE WARMEST OF THE WEEK. THE HIGH AND WEAK ONSHORE
GRADS SHOULD KEEP THE MARINE LAYER CONFINED TO THE IMMEDIATE COAST
AT BEST...WHICH FURTHER HINTS AT A WARM MIDWEEK. THERE IS A WILDCARD
IN A WEAK CUTOFF LOW TO THE WEST. THIS PATTERN WILL CREATE AN
EAST-WEST TEMP GRAD THAT MODELS CURRENTLY HAVE US SITTING IN THE
WARM SECTOR WED AND THU...BUT THIS PATTERN COULD SHIFT AND TEMPS
COULD BE A BIT COOLER. NOT ONLY THAT...BUT A WHEN QUESTION EXISTS AS
WELL...AS TO WHEN WILL THINGS FINALLY SHIFT TO THE EAST. CURRENTLY
THE GFS AND ECMWF ARE BEHAVING NICELY...WITH A TROUGH DIGGING INTO
THE LOW TO THE WEST AND PUSHING EVERYTHING EASTWARD ON FRI AND SAT.
THIS IS REFLECTED IN THE FORECAST WITH SOME COOLING...BUT CONFIDENCE
IS LOW THIS FAR OUT.
&&
.AVIATION...20/2000Z.
AN EDDY WILL SPIN UP A MARINE LAYER TONIGHT...BRINGING LOW CLOUDS
AND PATCHY FOG WITH MVFR CONDITIONS TO AT LEAST LA AND VENTURA
COUNTY COASTAL SECTIONS. OF GREATER UNCERTAINTY IS WHETHER THE LOW
CLOUDS AND FOG WILL ALSO SPREAD TO THE SANTA BARBARA SOUTH COAST AND
THE LA COUNTY VALLEY TAF SITES. THE CENTRAL COAST AND KPRB ARE
LIKELY TO HAVE LOW CLOUDS AND FOG WITH MVFR CONDITIONS OVERNIGHT.
KLAX...FAIR TO GOOD CONFIDENCE IN THE CURRENT TAF. CLEAR SKIES UNTIL
07Z WHEN LOW CLOUDS AND PATCHY FOG WILL ARRIVE WITH MVFR CONDITIONS.
A 40 PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AS SOON AS 05Z OR
AS LATE AS 09Z. THEN LOW CLOUDS AND FOG UNTIL LATE MORNING SUNDAY.
KBUR...LITTLE OR NO CONFIDENCE IN THE TAF FORECAST FOR KBUR. A 50
PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AFTER MIDNIGHT...AND A
50 PERCENT CHANCE
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KAPLAN/KITTELL
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 210325
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
830 PM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 8:30 PM PDT SATURDAY...TWO RECORDS WERE SET TODAY
AT SAN JOSE INTERNATIONAL AIRPORT AND SALINAS AIRPORT. ODDLY ENOUGH
IT WAS FOR RECORD RAINFALL WHICH IS UNUSUAL FOR THIS TIME OF YEAR.
SAN JOSE RECEIVED A TRACE OF RAIN BREAKING ITS PREVIOUS RECORD
FOR THE DAY OF 0.00 INCHES FROM RECORDS DATING BACK TO 1947 WHILE
SALINAS RECORDED ONE HUNDREDTH OF AN INCH TYING ITS RECORD SET BACK
IN 1973. NEEDLESS TO SAY VERY MOIST CONDITIONS EXISTED ACROSS THE
REGION THIS MORNING WITH EXTENSIVE LOW CLOUDS AND RECORDED RAINFALL
IN VARIOUS LOCATIONS. MANY LOCATIONS ACROSS THE DISTRICT SAW
TEMPERATURES UP TO FIVE DEGREES COOLER THAN YESTERDAY AS A RESULT OF
LOW LEVEL CLOUDS THAT LINGERED WELL INTO THE AFTERNOON IN SOME
AREAS.
SATELLITE IMAGERY SHOWS A LARGE PATCH OF STRATUS MOVING SOUTH ALONG
THE COAST THIS EVENING. AN INCREASING NORTHERLY GRADIENT WILL MOVE
THIS AREA OF STRATUS DOWN THE CENTRAL COAST OVERNIGHT. ALTHOUGH THIS
SWATH OF LOW CLOUDS WILL KEEP AREAS ALONG THE COAST MOIST OVERNIGHT
AND INTO SUNDAY DRIER CONDITIONS ARE IN-STORE FOR THE INLAND AREAS.
A WEAK UPPER LEVEL TROUGH IS SLATED TO SWINGS ACROSS THE NORTHERNMOST
PART OF THE STATE SUNDAY AFTERNOON KEEPING THE BOUNDARY LAYER MIXED
OUT AND THE MARINE LAYER FROM BEING ABLE TO REDEVELOPING. HIGH
PRESSURE WILL BEGIN MOVING IN OVER THE PACIFIC NORTHWEST ON SUNDAY
USHERING IN A WARMER AND DRIER AIRMASS WITH IT. THIS WILL GREATLY
IMPACT THE FORMATION OF STRATUS AND RESULT IN A WARMER TEMPERATURES
BEGINNING ON MONDAY.
FROM PREVIOUS DISCUSSION...THE MODELS MAINTAIN A NEARLY ZONAL UPPER
LEVEL FLOW ACROSS CA WITH RELATIVELY HIGH HEIGHTS THROUGH MOST OF
NEXT WEEK. TEMPERATURES SHOULD WARM TO NEAR NORMAL ON MONDAY AND THEN
REMAIN AT OR SLIGHTLY ABOVE NORMAL FOR THE REMAINDER OF THE WEEK. A
TROUGH MOVING INTO THE PAC NW AROUND MIDWEEK LOOKS AS THOUGH IT WILL
BE TOO FAR NORTH TO HAVE MUCH IMPACT ON OUR WEATHER. TOUGH TO SAY
WHEN A MARINE LAYER MIGHT REDEVELOP...BUT MOST LIKELY SCENARIO IS
AROUND MIDWEEK WHEN THE UPPER TROUGH MOVES INLAND TO OUR NORTH AND
TRIGGERS A SLIGHT INCREASE IN ONSHORE FLOW. THE MEDIUM RANGE MODELS
AGREE THAT A WEAK CUTOFF LOW WELL WEST OF BAJA WILL EJECT TO THE NE
LATE IN THE WEEK AND MOVE INLAND ACROSS CA BY LATE FRIDAY OR
SATURDAY. STILL TOO EARLY TO SAY IF THIS WILL HAVE MUCH OF AN IMPACT
ON OUR WEATHER...BUT MOISTURE WITH THIS UPPER LOW IS FORECAST TO BE
LACKING AND SO RAIN CHANCES ARE NO WHERE IN SIGHT AT THIS TIME.
&&
.AVIATION...AS OF 4:40 PM PDT SATURDAY...A TRANSITION TO A DRIER
FLOW IS BEGINNING. MORNING LOW CLOUDS HAVE CLEARED OUT IN MANY
AREAS THIS AFTERNOON BUT PATCHES OF LOW CLOUDS REMAIN. A RETURN OF
LOW CLOUDS IS EXPECTED TONIGHT BUT THE DURATION OF CLOUDINESS MAY
BE OFFSET BY THE VEERING OF LOW LEVEL WINDS TO THE N OVERNIGHT. THIS
TENDS TO ADD A DRYING EFFECT THOUGH DECOUPLING OF THE LOW LEVEL WINDS
SOMETIMES LESSENS THIS EFFECT DURING THE OVERNIGHT HOURS. IT SHOULD
LEAD TO AN EARLIER CLEARING OF LOW CLOUDS ON SUNDAY MORNING.
BAY AREA TERMINALS...LOW CLOUDS OVER SAN FRANCISCO WILL LIKELY KEEP
PUSHING INTO KSFO TERMINAL THROUGH THE EVENING BUT COULD BE MET
WITH OCCASIONAL SCATTERED CLOUDS LATER THIS EVENING AS THE LOW LEVEL
FLOW TURNS MORE TO THE NORTH. KSFO APPROACH SHOULD STAY VFR THROUGH
04Z-05Z THEN MAY FILL IN A BIT WITH LOW CLOUDS. KOAK WILL LIKELY STAY
BKN-OVC THROUGH THE EVENING AND OVERNIGHT. VFR IS EXPECTED SUNDAY.
CENTRAL COAST TERMINALS...VFR EXPECTED AT KMRY AND KSNS THROUGH 04Z
THEN TEMPO MVFR CEILINGS ARE POSSIBLE 04Z-08Z. AFTER 08Z LOCALIZED
IFR IS POSSIBLE UNTIL SUNDAY MORNING. CLEARING SHOULD BE FAIRLY
QUICK SUNDAY MORNING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
$$
PUBLIC FORECAST: C WALBRUN
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 210325
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
820 PM PDT SAT SEP 20 2008
.SHORT TERM (TODAY-TUESDAY)...
AS EXPECTED...TEMPS WERE COOLER JUST ABOUT EVERYWHERE TODAY AS 950
MB TEMPS COOLED NEARLY 5 DEGREES FRIDAY NIGHT INTO TODAY. SOME
LINGERING HIGHER RH VALUES ACROSS THE SAN JOAQUIN VALLEY AND DECENT
NRN GRADIENTS WILL HELP TO PUSH SOME CLOUDS INTO THE NRN SLOPES OF
SBA/VTU AND WESTERN LA COUNTY MTNS OVERNIGHT. THERE COULD BE SOME
LOCALLY DENSE FOG POSSIBLE ACROSS THE GRAPEVINE AFTER MIDNIGHT.
ALSO...EXPECT SOME LOCALLY GUSTY WINDS ACROSS THE I-5 CORRIDOR WITH
NORTHWEST TO NORTH WINDS 20 TO 30 MPH WITH GUSTS TO 40 MPH POSSIBLE
OVERNIGHT. THE SANTA BARBARA COUNTY MTNS AND ADJACENT SOUTH COAST
WILL EXPERIENCE GUSTY NORTHWEST TO NORTH WINDS THIS
EVENING...SHIFTING TO THE NORTHEAST LATER THIS EVENING. THIS WILL
CONTINUE TO AFFECT THE PASSES AND CANYONS NEAR GAVIOTA AND LAS
FLORES CANYON WITH GUSTS TO 40 MPH...THEN SHIFT THE FOCUS ON THE
FOOTHILLS ABOVE MONTECITO LATER TONIGHT. PORTIONS OF THE ANTELOPE
VALLEY WILL CONTINUE SW TO W WINDS 20 TO 30 MPH WITH LOCAL GUSTS TO
45 MPH...MAINLY NEAR THE SOLEDAD CYN PASS AND LAKE PALMDALE THIS
EVENING.
NOT MUCH CHANGE IN THE UPPER PATTERN AS BROAD NW FLOW WILL PERSIST
THROUGH SUNDAY. HOWEVER...A FAIRLY SIGNIFICANT EDDY BEGINS TO
DEVELOP OVERNIGHT AS MODERATE NW FLOW ACROSS THE OUTER WATERS
PERSISTS. LOW CLOUDS SHOULD BE BETTER ORGANIZED TO AFFECT THE LA
COUNTY COASTAL AREAS...POSSIBLY MAKING INTO VTU COUNTY COASTAL AREAS
LATE. LATEST SATELLITE IMAGERY DOES SHOW A MORE ORGANIZED AREA OF
STRATUS MOVING UP INTO ORANGE COUNTY AND SHOULD REACH LA COUNTY BY
MIDNIGHT. PRETTY GOOD CONFIDENCE THAT LOW CLOUDS SHOULD STAY OUT OF
SBA COUNTY SOUTH COAST DUE TO THE NORTHERLY GRADS THIS EVENING.
LATEST AMDAR SOUNDING NEAR KLAX SHOWS MARINE LAYER NEAR 1500
FT...BUT INVERSION REMAINS QUITE WEAK DUE TO COOLER AIR ADVECTION
EARLIER. THE CENTRAL COAST SHOULD SEE SOME PATCHY LOW CLOUDS
DEVELOP...ESPECIALLY BETWEEN LOMPOC AND SANTA MARIA...BUT NOT QUITE
AS ORGANIZED AS TO THE SOUTH AS SATELLITE IMAGERY INDICATES.
TEMPS SHOULD A BIT WARMER THEN WHAT MOS GUIDANCE WAS ADVERTISING N
OF POINT CONCEPTION DUE TO WEAK OFFSHORE FLOW FORECAST IN THE
MORNING. NOT MUCH CHANGE EXPECTED FOR THE COASTAL AREAS OF LA/VTU
COUNTIES...BUT TEMPS SHOULD REBOUND A COUPLE OF DEGREES ACROSS
INLAND AREAS.
HIGH PRESSURE ALOFT WILL BEGIN TO BUILD IN FROM THE SOUTH SLOWLY ON
MONDAY...AND STRENGTHEN TO A 590 DM HIGH BY EARLY TUE.
THEREFORE...TEMPS WILL BEGIN TO WARM UP BOTH DAYS...ESPECIALLY TUE.
SFC GRADS WHICH LOOKED TO BE LIGHTLY TO MODERATE OFFSHORE A FEW DAYS
AGO...NOW LOOKS MORE WEAKLY NEUTRAL. NEVERTHELESS...THIS SHOULD HELP
TEMPS TO WARM UP INTO THE LOWER 90S ACROSS THE WARMEST INTERIOR
LOCATIONS OF THE FORECAST AREA.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (WEDNESDAY-SATURDAY)...
WITH ONSHORE GRADS WEAKENING AND THE RIDGE CONTINUING ITS BUILD UP
FROM THE SOUTH...WED AND THU LOOKS TO REMAIN WARM...WITH ONE OF
THOSE DAYS BEING THE WARMEST OF THE WEEK. THE HIGH AND WEAK ONSHORE
GRADS SHOULD KEEP THE MARINE LAYER CONFINED TO THE IMMEDIATE COAST
AT BEST...WHICH FURTHER HINTS AT A WARM MIDWEEK. THERE IS A WILDCARD
IN A WEAK CUTOFF LOW TO THE WEST. THIS PATTERN WILL CREATE AN
EAST-WEST TEMP GRAD THAT MODELS CURRENTLY HAVE US SITTING IN THE
WARM SECTOR WED AND THU...BUT THIS PATTERN COULD SHIFT AND TEMPS
COULD BE A BIT COOLER. NOT ONLY THAT...BUT A WHEN QUESTION EXISTS AS
WELL...AS TO WHEN WILL THINGS FINALLY SHIFT TO THE EAST. CURRENTLY
THE GFS AND ECMWF ARE BEHAVING NICELY...WITH A TROUGH DIGGING INTO
THE LOW TO THE WEST AND PUSHING EVERYTHING EASTWARD ON FRI AND SAT.
THIS IS REFLECTED IN THE FORECAST WITH SOME COOLING...BUT CONFIDENCE
IS LOW THIS FAR OUT.
&&
.AVIATION...20/2000Z.
AN EDDY WILL SPIN UP A MARINE LAYER TONIGHT...BRINGING LOW CLOUDS
AND PATCHY FOG WITH MVFR CONDITIONS TO AT LEAST LA AND VENTURA
COUNTY COASTAL SECTIONS. OF GREATER UNCERTAINTY IS WHETHER THE LOW
CLOUDS AND FOG WILL ALSO SPREAD TO THE SANTA BARBARA SOUTH COAST AND
THE LA COUNTY VALLEY TAF SITES. THE CENTRAL COAST AND KPRB ARE
LIKELY TO HAVE LOW CLOUDS AND FOG WITH MVFR CONDITIONS OVERNIGHT.
KLAX...FAIR TO GOOD CONFIDENCE IN THE CURRENT TAF. CLEAR SKIES UNTIL
07Z WHEN LOW CLOUDS AND PATCHY FOG WILL ARRIVE WITH MVFR CONDITIONS.
A 40 PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AS SOON AS 05Z OR
AS LATE AS 09Z. THEN LOW CLOUDS AND FOG UNTIL LATE MORNING SUNDAY.
KBUR...LITTLE OR NO CONFIDENCE IN THE TAF FORECAST FOR KBUR. A 50
PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AFTER MIDNIGHT...AND A
50 PERCENT CHANCE
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 210201
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
701 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN SUNDAY.
OTHERWISE...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT
SOUTHWEST THE NEXT COUPLE DAYS AS AN AREA OF LOW PRESSURE PASSES TO
THE NORTH. DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY
CLEAR SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
QUICK UPDATE TO TAKE POPS OUT OF THE FIRST PERIOD. A CELL TRIED TO
DEVELOP SOUTHEAST OF GILA BEND AND ANOTHER ONE DEVELOPED SOUTH OF
CASA GRANDE....HOWEVER HAVE SINCE DISSIPATED. THESE WERE OVER
UNPOPULATED AREAS...WERE SHORT LIVED...HAD NO LIGHTNING...AND LIKELY
PRODUCED LITTLE IF ANY RAINFALL. SATELLITE SHOWS THAT ALL THAT
REMAINS IS A LITTLE CLOUDINESS IN SOUTHEAST MARICOPA...CENTRAL PINAL
AND SOUTHERN GILA COUNTIES. NOW THAT THE SUN HAS SET...EXPECT
REMAINING CLOUDS TO BEGIN THINNING OUT...LEAVING MOSTLY CLEAR SKIES
OVER THE ENTIRE FORECAST AREA.
WILL TAKE A LOOK AT TEMPERATURES...DEWPOINTS...AND WINDS SHORTLY TO
SEE IF THEY REQUIRE UPDATING. IF NECESSARY WILL ISSUE SECOND UPDATE
IN COUPLE OF HOURS.
REMAINDER OF EARLIER DISCUSSION FOLLOWS...
WITH IMPROVED MOISTURE PROGGED OVER ZONE 24 FOR SUNDAY...NUDGED UP
POPS THERE OVER THE MOUNTAINS A LITTLE BIT. ON MONDAY...AN OPEN WAVE
TROUGH TAKES THE PLACE OF THE LOW CURRENTLY MOVING THROUGH THE
INTERIOR NORTHWEST. THIS WILL HELP ADVANCE THE DRIER AIR ALREADY
OVER WESTERN PORTIONS OF THE FORECAST AREA INTO SOUTH-CENTRAL
ARIZONA. THESE FEATURES WILL ALSO HELP TO KEEP THE RIDGE A FLAT IN
PLACE WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. THEREAFTER...A RIDGE
BEGINS BUILDING OVER THE DESERT SOUTHWEST...THOUGH HEIGHTS DONT
APPEAR TO SHOOT UP TOO HIGH. WITH THE WESTERLIES WAXING AND WANING
LOCALLY BREEZY TO WINDY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY
IN SOUTHEAST CALIFORNIA.
WEDNESDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
THE CUMULUS CLOUD DECK OVER EAST CENTRAL ARIZONA WILL BEGIN
DISSIPATING AFTER SUNSET...WITH MOSTLY CLEAR SKIES EXPECTED
OVERNIGHT AND THROUGH MID-DAY ON SUNDAY. SOME RESIDUAL LOW LEVEL
MOISTURE WILL REMAIN ON SUNDAY. THIS WILL ENABLE SCATTERED TO BROKEN
CUMULUS CLOUDS TO FORM ONCE AGAIN DURING THE AFTERNOON AND EARLY
EVENING...WITH CLOUD BASES RANGING FROM AROUND 090 TO 120 KFT.
WINDS AT KPHX AND KIWA WILL BE LIGHT OUT OF THE SOUTHWEST TO WEST
THROUGH EARLY MORNING...WHEN THE NORMAL DIURNAL SHIFT TO A MORE
SOUTHEAST DIRECTION OCCURS. AT KYUM AND KIPL WINDS WILL FAVOR A
SOUTH DIRECTION...THOUGH WINDS WILL BE LIGHT AND DIRECTION WILL BE
VARIABLE. OCCASIONAL GUSTY SOUTHWEST WINDS ARE EXPECTED AT KBLH
THROUGH AROUND 03Z THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/AJ
AVIATION...MCLANE
FIRE WEATHER...SIPPLE
000
FXUS66 KMTR 202348
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
440 PM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 2:50 PM PDT SATURDAY...SKIES WERE SLOW TO CLEAR
TODAY...BUT BY EARLY AFTERNOON MOSTLY SUNNY CONDITIONS HAD DEVELOPED
ACROSS NEARLY OUR ENTIRE FORECAST AREA. THE LOW LEVELS ARE STILL
RATHER MOIST AND LIGHT ONSHORE FLOW WILL CONTINUE IN THE SHORT-TERM.
THUS...EXPECT INCREASING AREAS OF LOW CLOUDS OVERNIGHT. INLAND
EXTENT OF LOW CLOUDINESS SHOULD BE SOMEWHAT LESS EXTENSIVE DUE TO
GRADUALLY INCREASING NORTHERLY SURFACE GRADIENTS.
A SHORTWAVE TROUGH ALOFT IS FORECAST TO SLIDE ACROSS FAR NORTHERN
CA ON SUNDAY AFTERNOON. PASSAGE OF THIS UPPER LEVEL FEATURE WILL
TRIGGER BETTER LOW LEVEL MIXING SUNDAY AFTERNOON AND EVENING AND AN
OVERALL REDUCTION IN LOW CLOUDINESS. THEN...BY SUNDAY NIGHT SURFACE
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE PACIFIC NORTHWEST. THIS
WILL RESULT IN WEAKENED ONSHORE FLOW SUNDAY NIGHT AND MONDAY...
CLEARING OF MOST REMAINING LOW CLOUDS...AND A WARM-UP OF SEVERAL
DEGREES ON MONDAY.
THE MODELS MAINTAIN A NEARLY ZONAL UPPER LEVEL FLOW ACROSS CA WITH
RELATIVELY HIGH HEIGHTS THROUGH MOST OF NEXT WEEK. TEMPERATURES
SHOULD WARM TO NEAR NORMAL ON MONDAY AND THEN REMAIN AT OR SLIGHTLY
ABOVE NORMAL FOR THE REMAINDER OF THE WEEK. A TROUGH MOVING INTO
THE PAC NW AROUND MIDWEEK LOOKS AS THOUGH IT WILL BE TOO FAR NORTH
TO HAVE MUCH IMPACT ON OUR WEATHER. TOUGH TO SAY WHEN A MARINE
LAYER MIGHT REDEVELOP...BUT MOST LIKELY SCENARIO IS AROUND MIDWEEK
WHEN THE UPPER TROUGH MOVES INLAND TO OUR NORTH AND TRIGGERS A
SLIGHT INCREASE IN ONSHORE FLOW. THE MEDIUM RANGE MODELS AGREE THAT
A WEAK CUTOFF LOW WELL WEST OF BAJA WILL EJECT TO THE NE LATE IN
THE WEEK AND MOVE INLAND ACROSS CA BY LATE FRIDAY OR SATURDAY. STILL
TOO EARLY TO SAY IF THIS WILL HAVE MUCH OF AN IMPACT ON OUR
WEATHER...BUT MOISTURE WITH THIS UPPER LOW IS FORECAST TO BE LACKING
AND SO RAIN CHANCES ARE NO WHERE IN SIGHT AT THIS TIME.
&&
.AVIATION...AS OF 4:40 PM PDT SATURDAY...A TRANSITION TO A DRIER
FLOW IS BEGINNING. MORNING LOW CLOUDS HAVE CLEARED OUT IN MANY
AREAS THIS AFTERNOON BUT PATCHES OF LOW CLOUDS REMAIN. A RETURN OF
LOW CLOUDS IS EXPECTED TONIGHT BUT THE DURATION OF CLOUDINESS MAY
BE OFFSET BY THE VEERING OF LOW LEVEL WINDS TO THE N OVERNIGHT. THIS
TENDS TO ADD A DRYING EFFECT THOUGH DECOUPLING OF THE LOW LEVEL WINDS
SOMETIMES LESSENS THIS EFFECT DURING THE OVERNIGHT HOURS. IT SHOULD
LEAD TO AN EARLIER CLEARING OF LOW CLOUDS ON SUNDAY MORNING.
BAY AREA TERMINALS...LOW CLOUDS OVER SAN FRANCISCO WILL LIKELY KEEP
PUSHING INTO KSFO TERMINAL THROUGH THE EVENING BUT COULD BE MET
WITH OCCASIONAL SCATTERED CLOUDS LATER THIS EVENING AS THE LOW LEVEL
FLOW TURNS MORE TO THE NORTH. KSFO APPROACH SHOULD STAY VFR THROUGH
04Z-05Z THEN MAY FILL IN A BIT WITH LOW CLOUDS. KOAK WILL LIKELY STAY
BKN-OVC THROUGH THE EVENING AND OVERNIGHT. VFR IS EXPECTED SUNDAY.
CENTRAL COAST TERMINALS...VFR EXPECTED AT KMRY AND KSNS THROUGH 04Z
THEN TEMPO MVFR CEILINGS ARE POSSIBLE 04Z-08Z. AFTER 08Z LOCALIZED
IFR IS POSSIBLE UNTIL SUNDAY MORNING. CLEARING SHOULD BE FAIRLY
QUICK SUNDAY MORNING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
POINT ARENA TO PIGEON PT 20-60 NM...LATE TNGT
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 202346
AFDPSR
AREA FORECAST DISCUSSION...AVIATION SECTION UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
445 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...UPDATED AVIATION SECTION.
&&
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN SUNDAY.
OTHERWISE...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT
SOUTHWEST THE NEXT COUPLE DAYS AS AN AREA OF LOW PRESSURE PASSES TO
THE NORTH. DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY
CLEAR SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
CONSIDERABLE CUMULUS CLOUDINESS WITH SOME VERTICAL DEVELOPMENT BUT
THERE APPEARS TO BE A CAP SO FAR AS NO DEEP MOIST CONVECTION HAS
TAKEN OFF YET. WILL HANG ON TO THE SMALL AREA OF 10 PERCENT POPS
OVER WESTERN PORTIONS OF MARICOPA COUNTY THIS EVENING AS THIS
APPEARS TO HAVE THE DEEPEST CUMULUS DEVELOPMENT. WITH IMPROVED
MOISTURE PROGGED OVER ZONE 24 FOR SUNDAY...NUDGED UP POPS THERE OVER
THE MOUNTAINS A LITTLE BIT. ON MONDAY...AN OPEN WAVE TROUGH TAKES
THE PLACE OF THE LOW CURRENTLY MOVING THROUGH THE INTERIOR
NORTHWEST. THIS WILL HELP ADVANCE THE DRIER AIR ALREADY OVER WESTERN
PORTIONS OF THE FORECAST AREA INTO SOUTH-CENTRAL ARIZONA. THESE
FEATURES WILL ALSO HELP TO KEEP THE RIDGE A FLAT IN PLACE WITH
SLIGHTLY ABOVE NORMAL TEMPERATURES. THEREAFTER...A RIDGE BEGINS
BUILDING OVER THE DESERT SOUTHWEST...THOUGH HEIGHTS DONT APPEAR TO
SHOOT UP TOO HIGH. WITH THE WESTERLIES WAXING AND WANING LOCALLY
BREEZY TO WINDY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY IN
SOUTHEAST CALIFORNIA.
WEDNESDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
THE CUMULUS CLOUD DECK OVER EAST CENTRAL ARIZONA WILL BEGIN
DISSIPATING AFTER SUNSET...WITH MOSTLY CLEAR SKIES EXPECTED
OVERNIGHT AND THROUGH MID-DAY ON SUNDAY. SOME RESIDUAL LOW LEVEL
MOISTURE WILL REMAIN ON SUNDAY. THIS WILL ENABLE SCATTERED TO BROKEN
CUMULUS CLOUDS TO FORM ONCE AGAIN DURING THE AFTERNOON AND EARLY
EVENING...WITH CLOUD BASES RANGING FROM AROUND 090 TO 120 KFT.
WINDS AT KPHX AND KIWA WILL BE LIGHT OUT OF THE SOUTHWEST TO WEST
THROUGH EARLY MORNING...WHEN THE NORMAL DIURNAL SHIFT TO A MORE
SOUTHEAST DIRECTION OCCURS. AT KYUM AND KIPL WINDS WILL FAVOR A
SOUTH DIRECTION...THOUGH WINDS WILL BE LIGHT AND DIRECTION WILL BE
VARIABLE. OCCASIONAL GUSTY SOUTHWEST WINDS ARE EXPECTED AT KBLH
THROUGH AROUND 03Z THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...MCLANE
FIRE WEATHER...SIPPLE
000
FXUS66 KEKA 202250 AAA
AFDEKA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE EUREKA CA
350 PM PDT SAT SEP 20 2008
.SYNOPSIS...COOL WEATHER WILL PREVAIL OVER THE INTERIOR THROUGH
SUNDAY WITH NIGHT AND MORNING CLOUDS AND FOG CONTINUING NEAR THE
COAST. WEAK HIGH PRESSURE WILL BRING A WARMING TREND TO INLAND
LOCATIONS BEGINNING MONDAY.
&&
.SHORT TERM...MOISTURE LEFTOVER FROM YESTERDAY`S UPPER LOW HAS BEEN
SUFFICIENT TO PRODUCE CU BUILDUPS OVER THE HIGHER TERRAIN TODAY.
CLEARING SKIES WILL LEAD TO A COLDER NIGHT OVER THE INTERIOR
TONIGHT. A WEAK TROUGH WILL PASS THROUGH THE PACIFIC NORTHWEST LATE
SUNDAY...BUT WILL BRING LITTLE CHANGE TO THE WEATHER OTHER THAN
INCREASED CLOUD COVER IN THE NORTHERN PORTION OF THE CWA. WEAK
RIDGING WILL BUILD OVER THE EASTERN PACIFIC EARLY NEXT WEEK AND
BRING A WARMING AND DRYING TREND TO INLAND AREAS BEGINNING MONDAY. KL
.LONG TERM...WEDNESDAY THROUGH SATURDAY...THE WEAK UPPER RIDGE OVER
THE WEST COAST ON TUESDAY WILL SHIFT EASTWARD TUESDAY NIGHT IN
RESPONSE TO AN APPROACHING UPPER TROUGH. THIS TROUGH FORECAST TO
CROSS 130 W LATITUDE BY 1200 UTC WEDNESDAY. THIS FEATURE IS FORECAST
TO WEAKEN AS IT APPROACHES THE COAST...HOWEVER STILL APPEARS TO HAVE
SUFFICIENT MOISTURE TO PRODUCE A CHANCE OF LIGHT RAIN OVER THE
NORTHWEST CWA WEDNESDAY AFTERNOON. THE MEDIUM RANGE MODELS AGREE
FAIRLY WELL ON THE STRENGTH AND TIMING OF THIS FEATURE...FOLLOWED BY
REASONABLE AGREEMENT IN DEPICTING SHORT WAVE RIDGING FOR THE REGION
THURSDAY AND FRIDAY AHEAD OF ANOTHER TROUGH FOR LATE FRIDAY INTO
SATURDAY. CMC
&&
.AVIATION...WITH LIGHT WINDS ACROSS THE FORECAST AREA...SCT-BKN
CLOUDS ACROSS THE FORECAST AREA WILL BE SLOW TO SCATTER THIS
EVENING. ALTO CU OVER MOUNTAINS SHOULD CLEAR SHORTLY AFTER SUNSET.
NW WINDS OFFSHORE WILL INCREASE THIS AFTERNOON AND CONTINUE TO CLEAR
CLOUDS ALONG THE NORTH COAST FROM THE COAST INWARD. HOWEVER EXPECT
LOW CLOUDS AND MVFR FLIGHT CONDITIONS ALONG THE NORTH COAST LATE
TONIGHT. TH
&&
.MARINE...N-NW WINDS WILL INCREASE SUN AND MON AS HIGH PRESSURE
BUILDS OVER THE EAST PACIFIC. WINDS ARE EXPECTED TO INCREASE TO SCA
LEVELS OVER THE SOUTHERN OUTER WATERS SUNDAY. MODELS ARE BETTER
ALIGNED ON THE TIMING OF THE WEAK FRONT THAT WILL JUST CLIP THE
NORTHERN WATERS. THE PRESSURE GRADIENT WILL WEAKEN AS THE FRONT
NEARS TUE NIGHT...AND STRENGTHEN BEHIND THE FRONT ON THU. TH
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS65 KPSR 202229 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
328 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...UPDATED FIRE WEATHER DISCUSSION.
&&
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN SUNDAY.
OTHERWISE...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT
SOUTHWEST THE NEXT COUPLE DAYS AS AN AREA OF LOW PRESSURE PASSES TO
THE NORTH. DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY
CLEAR SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
CONSIDERABLE CUMULUS CLOUDINESS WITH SOME VERTICAL DEVELOPMENT BUT
THERE APPEARS TO BE A CAP SO FAR AS NO DEEP MOIST CONVECTION HAS
TAKEN OFF YET. WILL HANG ON TO THE SMALL AREA OF 10 PERCENT POPS
OVER WESTERN PORTIONS OF MARICOPA COUNTY THIS EVENING AS THIS
APPEARS TO HAVE THE DEEPEST CUMULUS DEVELOPMENT. WITH IMPROVED
MOISTURE PROGGED OVER ZONE 24 FOR SUNDAY...NUDGED UP POPS THERE OVER
THE MOUNTAINS A LITTLE BIT. ON MONDAY...AN OPEN WAVE TROUGH TAKES
THE PLACE OF THE LOW CURRENTLY MOVING THROUGH THE INTERIOR
NORTHWEST. THIS WILL HELP ADVANCE THE DRIER AIR ALREADY OVER WESTERN
PORTIONS OF THE FORECAST AREA INTO SOUTH-CENTRAL ARIZONA. THESE
FEATURES WILL ALSO HELP TO KEEP THE RIDGE A FLAT IN PLACE WITH
SLIGHTLY ABOVE NORMAL TEMPERATURES. THEREAFTER...A RIDGE BEGINS
BUILDING OVER THE DESERT SOUTHWEST...THOUGH HEIGHTS DONT APPEAR TO
SHOOT UP TOO HIGH. WITH THE WESTERLIES WAXING AND WANING LOCALLY
BREEZY TO WINDY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY IN
SOUTHEAST CALIFORNIA.
WEDNESDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
MID LEVEL MSTR BLO 15 THSD FT REMAINED IN PLACE THIS MORNING BENEATH
A SHARP INVRN...PER PSR SOUNDING. CLOUDS BTWN 9 AND 12 THSD FT AT
SKY HARBOR WILL LIKELY DECREASE BY 02Z. SFC WNDS WILL ALSO DROP
OFF BY 03Z...VEER SLOWLY...AND BECOME LIGHT/EASTERLY.
NO AVIATION CONCERNS FOR LOWER COLORADO RIVER VALLEY OR KIPL
TAFS...ALTHO OCNL GUSTY WINDS ARE STILL PSBL AT KIPL AND KBLH THRU
03Z THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
EXTENDED PERIOD...MOSTLY CLEAR SKIES AND DRY CONDITIONS ARE
EXPECTED FOR TUESDAY THROUGH SATURDAY. ALTHOUGH MINIMUM RH VALUES
ARE EXPECTED TO DIP TO 10 TO 15 PERCENT BY THE MIDDLE OF THE
WEEK...WINDS AT THAT TIME ARE NOT EXPECTED TO REACH CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...SIPPLE
FIRE WEATHER...SIPPLE
000
FXUS65 KREV 202200
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
300 PM PDT SAT SEP 20 2008
.SHORT TERM...
SHOWER POTENTIAL NEAR THE OREGON BORDER HAS WANED SINCE NOON AS
DRIER AIR OFF THE WARNER MTS HAVE SUPPRESSED VERTICAL GROWTH OF
THE EXISTING CUMULUS DECK. WITH THE UPPER LOW LIFTING OUT THIS
EVENING...NO MORE PRECIP IS EXPECTED ACROSS THE REGION THRU
TONIGHT. NEXT SHORTWAVE APPROACHING THE NWRN US HAS BEEN TRENDING
A BIT FARTHER SOUTH WITH ITS TRACK AND HIGH CLOUDS AHEAD OF THIS
SYSTEM WILL SPREAD INTO AREAS FROM HIGHWAY 50 NWD BY LATE TONIGHT
THRU SUNDAY MORNING.
ALTHOUGH THIS SYSTEM WILL NOT HAVE MUCH MOISTURE TO WORK
WITH...INSTBY IN NWRN NV AND FAR NERN CA WILL INCREASE WHILE THESE
AREAS WILL ALSO BE UNDER THE FAVORABLE LEFT EXIT REGION OF AN UPPER
LEVEL JET STREAK FOR ENHANCED LIFT. AS A RESULT...SLGT CHC OF
TSTMS WILL BE ADDED TO AREAS NORTH OF SUSANVILLE FROM 22Z-03Z
SUNDAY AFTN-EVE...WITH A THREAT OF SHOWERS THRU SUN EVENING
EXTENDING ACROSS NRN PERSHING COUNTY. THE 18Z NAM INDICATES ISOLD
PRECIP POTENTIAL EVEN FARTHER SOUTH TO NEAR PYRAMID LAKE...BUT AT
THIS TIME THE CONVECTIVE THREAT WILL NOT BE EXTENDED THAT FAR
SOUTH. WINDS WILL INCREASE SUNDAY AFTERNOON WITH GUSTS OF 25-30
MPH IN MOST ZONES.
FOR MON-TUES...ZONAL FLOW WILL WEAKEN AS RIDGE BUILDS ACROSS THE
SWRN US AND NRN MEXICO...ALLOWING FOR RISES IN 500 MB HEIGHTS AND
700 MB TEMPS. WHILE REDUCED MIXING DUE TO LIGHT NE-E WINDS ON
MONDAY WILL PREVENT MUCH RISE IN TEMPS ON MONDAY...THE RETURN TO
MODERATE AFTERNOON WESTERLIES WILL ALLOW FOR A MORE NOTABLE
WARMUP INTO THE LOWER-MID 80S FOR THE WRN NV VALLEYS ON TUESDAY.
DRY AND STABLE CONDITIONS WILL PREVAIL BOTH DAYS. MJD
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
WARM AND DRY CONDITIONS EXPECTED THROUGH THE EXTENDED PERIOD. ZONAL
FLOW WILL SET UP ACROSS THE NRN TIER ON WEDNESDAY AS HIGH PRESSURE
BUILDS OVER THE SWRN CONUS. A WEEK SHORTWAVE IS PROGGED TO MOVE
ACROSS THE PACIFIC NW ON WEDNESDAY BUT THE RIDGE SHOULD KEEP THE
DYNAMICS AND ANY ASSOCIATED PRECIP FAR TO OUR NORTH.
ON THURSDAY BOTH THE GFS AND ECMWF SHOW A WEAK TROUGH FORMING NEAR
30N 130W. AS MENTIONED IN THE MORNING DISCUSSION...THIS FEATURE
SHOULD HELP TO ADVECT MOISTURE NORTH INTO THE WRN GREAT BASIN. THE
MOISTURE IS NEGLIGIBLE ON THURSDAY BUT BY FRIDAY THE GFS BRINGS
PRECIPITABLE WATER AMOUNTS OF AROUND 0.50 INCH INTO NEVADA. THE
PROGRESSIVE PATTERN SHOULD PULL THE ERN PACIFIC TROUGH TOWARD THE
CALIFORNIA COAST ON FRIDAY AND THEN INTO IDAHO ON SATURDAY.
WILL CONTINUE WITH A DRY FORECAST FOR THE EXTENDED AS DEEP MOISTURE
MAY NOT HAVE ENOUGH TIME TO MOVE NORTH AND SATURATE THE LWR
ATMOSPHERE. ALSO...WITH A LACK OF SIGNIFICANT CLOUD COVER...
TEMPERATURES WILL SEE A GRADUAL WARMING TREND WITH HIGHS AROUND 5
DEGREES ABOVE NORMAL BY WEEK`S END. O`HARA
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY. W-NW WIND GUSTS OF
20-25 KT THRU 04Z THIS EVENING AND SUNDAY AFTN-EVE FROM 21Z-04Z.
LOCALLY STRONGER GUSTS POSSIBLE NEAR ISOLD -SHRA/-TSRA AFT 22Z
SUNDAY NORTH OF SUSANVILLE-GERLACH LINE. O`HARA/MJD &&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KMTR 202153
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
250 PM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 2:50 PM PDT SATURDAY...SKIES WERE SLOW TO CLEAR
TODAY...BUT BY EARLY AFTERNOON MOSTLY SUNNY CONDITIONS HAD DEVELOPED
ACROSS NEARLY OUR ENTIRE FORECAST AREA. THE LOW LEVELS ARE STILL
RATHER MOIST AND LIGHT ONSHORE FLOW WILL CONTINUE IN THE SHORT-TERM.
THUS...EXPECT INCREASING AREAS OF LOW CLOUDS OVERNIGHT. INLAND
EXTENT OF LOW CLOUDINESS SHOULD BE SOMEWHAT LESS EXTENSIVE DUE TO
GRADUALLY INCREASING NORTHERLY SURFACE GRADIENTS.
A SHORTWAVE TROUGH ALOFT IS FORECAST TO SLIDE ACROSS FAR NORTHERN
CA ON SUNDAY AFTERNOON. PASSAGE OF THIS UPPER LEVEL FEATURE WILL
TRIGGER BETTER LOW LEVEL MIXING SUNDAY AFTERNOON AND EVENING AND AN
OVERALL REDUCTION IN LOW CLOUDINESS. THEN...BY SUNDAY NIGHT SURFACE
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE PACIFIC NORTHWEST. THIS
WILL RESULT IN WEAKENED ONSHORE FLOW SUNDAY NIGHT AND MONDAY...
CLEARING OF MOST REMAINING LOW CLOUDS...AND A WARM-UP OF SEVERAL
DEGREES ON MONDAY.
THE MODELS MAINTAIN A NEARLY ZONAL UPPER LEVEL FLOW ACROSS CA WITH
RELATIVELY HIGH HEIGHTS THROUGH MOST OF NEXT WEEK. TEMPERATURES
SHOULD WARM TO NEAR NORMAL ON MONDAY AND THEN REMAIN AT OR SLIGHTLY
ABOVE NORMAL FOR THE REMAINDER OF THE WEEK. A TROUGH MOVING INTO
THE PAC NW AROUND MIDWEEK LOOKS AS THOUGH IT WILL BE TOO FAR NORTH
TO HAVE MUCH IMPACT ON OUR WEATHER. TOUGH TO SAY WHEN A MARINE
LAYER MIGHT REDEVELOP...BUT MOST LIKELY SCENARIO IS AROUND MIDWEEK
WHEN THE UPPER TROUGH MOVES INLAND TO OUR NORTH AND TRIGGERS A
SLIGHT INCREASE IN ONSHORE FLOW. THE MEDIUM RANGE MODELS AGREE THAT
A WEAK CUTOFF LOW WELL WEST OF BAJA WILL EJECT TO THE NE LATE IN
THE WEEK AND MOVE INLAND ACROSS CA BY LATE FRIDAY OR SATURDAY. STILL
TOO EARLY TO SAY IF THIS WILL HAVE MUCH OF AN IMPACT ON OUR
WEATHER...BUT MOISTURE WITH THIS UPPER LOW IS FORECAST TO BE LACKING
AND SO RAIN CHANCES ARE NO WHERE IN SIGHT AT THIS TIME.
&&
.AVIATION...AS OF 9:55 AM PDT SATURDAY...MVFR CIGS IN LOW CLOUD DECK
STARTING TO LIFT AS ATMOSPHERE STARTS A SLOW DRYING PROCESS TODAY.
CIGS WILL CONTINUE TO LIFT THROUGHOUT THE DAY WITH BASES AT OR ABOVE
3500 FT AFTER 12 NOON. MOST AREAS SHOULD SCATTER OUT BY LATE IN THE
AFTERNOON. EARLY EVENING VFR WITH SOME SCT DECKS ABOVE 3500 FT MSL.
HOWEVER...EXPECT THE MARINE LAYER TO REFORM AND MVFR CIGS TO DEVELOP
BY LATE EVENING...AND THE STRATUS TO MAKE A WEAK PUSH INLAND
OVERNIGHT INTO ONLY THE LOWER INTERMEDIATE VALLEYS...THAT IS LOWER
SALINAS VALLEY AND AROUND S.F.BAY. MODEL FORECAST ONSHORE GRADIENTS
APPEAR TO BE WEAK AND THE MARINE LAYER IS EXPECTED TO RANGE 1300 TO
1700 FT DEEP.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
POINT ARENA TO PIGEON PT 20-60 NM...LATE TNGT
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 202153
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
LINGERING MOISTURE OVER SOUTH-CENTRAL ARIZONA WILL LEAD TO A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE HIGHER TERRAIN SUNDAY.
OTHERWISE...DRIER AIR WILL SLOWLY MOVE EASTWARD ACROSS THE DESERT
SOUTHWEST THE NEXT COUPLE DAYS AS AN AREA OF LOW PRESSURE PASSES TO
THE NORTH. DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY
CLEAR SKIES AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
CONSIDERABLE CUMULUS CLOUDINESS WITH SOME VERTICAL DEVELOPMENT BUT
THERE APPEARS TO BE A CAP SO FAR AS NO DEEP MOIST CONVECTION HAS
TAKEN OFF YET. WILL HANG ON TO THE SMALL AREA OF 10 PERCENT POPS
OVER WESTERN PORTIONS OF MARICOPA COUNTY THIS EVENING AS THIS
APPEARS TO HAVE THE DEEPEST CUMULUS DEVELOPMENT. WITH IMPROVED
MOISTURE PROGGED OVER ZONE 24 FOR SUNDAY...NUDGED UP POPS THERE OVER
THE MOUNTAINS A LITTLE BIT. ON MONDAY...AN OPEN WAVE TROUGH TAKES
THE PLACE OF THE LOW CURRENTLY MOVING THROUGH THE INTERIOR
NORTHWEST. THIS WILL HELP ADVANCE THE DRIER AIR ALREADY OVER WESTERN
PORTIONS OF THE FORECAST AREA INTO SOUTH-CENTRAL ARIZONA. THESE
FEATURES WILL ALSO HELP TO KEEP THE RIDGE A FLAT IN PLACE WITH
SLIGHTLY ABOVE NORMAL TEMPERATURES. THEREAFTER...A RIDGE BEGINS
BUILDING OVER THE DESERT SOUTHWEST...THOUGH HEIGHTS DONT APPEAR TO
SHOOT UP TOO HIGH. WITH THE WESTERLIES WAXING AND WANING LOCALLY
BREEZY TO WINDY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY IN
SOUTHEAST CALIFORNIA.
WEDNESDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
MID LEVEL MSTR BLO 15 THSD FT REMAINED IN PLACE THIS MORNING BENEATH
A SHARP INVRN...PER PSR SOUNDING. CLOUDS BTWN 9 AND 12 THSD FT AT
SKY HARBOR WILL LIKELY DECREASE BY 02Z. SFC WNDS WILL ALSO DROP
OFF BY 03Z...VEER SLOWLY...AND BECOME LIGHT/EASTERLY.
NO AVIATION CONCERNS FOR LOWER COLORADO RIVER VALLEY OR KIPL
TAFS...ALTHO OCNL GUSTY WINDS ARE STILL PSBL AT KIPL AND KBLH THRU
03Z THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MOSTLY CLEAR SKIES WITH DRY CONDITIONS ARE EXPECTED THROUGH THE
EXTENDED. WINDS WILL INCREASE SUNDAY EVENING AND AGAIN
MONDAY...AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH THE PAC NW.
RH VALUES ARE EXPECTED TO DIP BELOW CRITICAL LEVELS ACROSS THE
SOUTHEAST CALIFORNIA DESERTS BY SUNDAY AFTERNOON...BUT SHOULD REMAIN
ABOVE CRITICAL LEVELS ELSEWHERE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...SIPPLE
FIRE WEATHER...WANEK
000
FXUS66 KHNX 202130
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
230 PM PDT SAT SEP 20 2008
.DISCUSSION...COOL AND STABLE AIRMASS OVER CENTRAL CALIFORNIA
CONTINUES TO PROVIDE FOR SUNNY SKIES THIS AFTERNOON. THE UPPER AIR
PATTERN WITH ITS NEGATIVELY TILTED TROUGH OVER THE WEST IS
FURTHERING THE ACTIVE WEATHER PATTERN OVER THE NORTHERN GREAT
BASIN AS IT REMAINS UNDER AN AREA OF DIFLUENCE. ACROSS CENTRAL
CALIFORNIA...A +70KT JET IN A ZONAL FLOW PATTERN HELPED INTRODUCE
THIS COOL AND STABLE AIRMASS TODAY WHICH WILL BEGIN MODIFYING BY
SUNDAY. TEMPERATURES HAVE HAD A DIFFICULT TIME REACHING THE 80S
OVER THE VALLEY TODAY AS MOST LOCATIONS WERE STILL IN THE 70S AS
OF 200 PM PDT. YET...850MB TEMP ANALYSIS SHOWS A 1-2 DEG-C
INCREASE BY SUNDAY...WHICH SHOULD ALLOW MANY MORE LOCATIONS TO
REACH IN THE 80S BY SUNDAY AFTERNOON. OTHERWISE...ZONAL TYPE FLOW
WILL CONTINUE ON SUNDAY WITH A STABLE ATMOSPHERE REMAINING OVER
CENTRAL CALIFORNIA. SHORT RANGE MODELS DO SHOW EMBEDDED WEAK
SHORT WAVE TROF/S MOVING THROUGH THE MAIN FLOW...BUT THE LACK ANY
REAL MOISTURE OR INSTABILITY WILL ALLOW MORE CLEAR SKIES THROUGH
THE WEEKEND. HOWEVER...THE LOW LEVEL NORTHWESTERLY FLOW INTRODUCED
BY THE TROUGH PASSAGE MAY ALLOW FOR SOME UPSLOPE CLOUDS TO DEVELOP
NEAR THE GRAPEVINE OVERNIGHT. YET...WILL NOT EXPECT ANY
PRECIPITATION WITH MOST OF THE CLOUDS BURNING OFF BY MID-DAY.
BEYOND SUNDAY...AN UPPER RIDGE IS STILL EXPECTED TO BUILD IN FROM
THE SOUTHWEST AND INTRODUCE A WARMING TREND BEGINNING EARLY NEXT
WEEK. THIS WARMING TREND WILL CONTINUE THROUGH MOST OF THE WEEK
AS THE RIDGE BECOMES THE DOMINATE FEATURE OVER THE WEST. LATEST
MODEL GUIDANCE HAS THE CENTRAL VALLEY WARMING BACK UP INTO THE MID
90S BY MID-WEEK BEFORE ANOTHER COOL DOWN IS INTRODUCED. MODELS
SHOW ANOTHER TROF ENTERING THE REGION BY THE END OF THE WEEK THAT
WILL USHER IN ANOTHER COOL DOWN OVER THE WEST. THE SYSTEM TOWARD
THE END OF THE WEEK WILL ALSO REMAIN DRY WITH NO WEATHER...BEYOND
WIND...EXPECTED OVER CENTRAL CALIFORNIA.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA
INTERIOR THROUGH 00Z MONDAY.
&&
.AIR QUALITY ISSUES...ON SUNDAY SEPTEMBER 21 2008...
UNHEALTHY FOR SENSITIVE GROUPS IN KERN COUNTY. FURTHER INFORMATION
IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...SANGER
WEATHER.GOV/HANFORD
000
FXUS66 KSTO 202126
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
230 PM PDT SAT SEP 20 2008
.DISCUSSION...
UPPER LOW MOVING EASTWARD INTO SOUTHERN IDAHO THIS AFTERNOON AS
SECONDARY SHORTWAVE TROUGH SLIDES SOUTHEASTWARD ACROSS NORTHERN
CALIFORNIA. SCATTERED TO BROKEN CUMULUS HAS DEVELOPED ACROSS MUCH OF
THE HIGHER TERRAIN THIS AFTERNOON...BUT MUCH DRIER AIR IN THE
MID-LEVELS AND LACK OF DEEP INSTABILITY HAS PREVENTED ANY SHOWERS.
TEMPERATURES REMAIN SLIGHTLY BELOW NORMAL BUT ARE RUNNING A FEW
DEGREES AHEAD OF FRIDAY/S READINGS.
RIDGING BRIEFLY REBUILD LATER TONIGHT BEFORE ANOTHER SHORTWAVE
MOVES ONSHORE SUNDAY...PERHAPS BRINGING A SHOWER OR TWO NEAR MT.
LASSEN. BEHIND THAT WAVE...DRIER NORTHERLY FLOW IS EXPECTED TO
DEVELOP SUNDAY NIGHT AND MONDAY AS THE UPPER RIDGE AMPLIFIES A BIT
OVER THE EASTERN PACIFIC.
&&
.EXTENDED DISCUSSION (TUESDAY NIGHT THROUGH SATURDAY)...
HI PRESSURE DEVELOPS NEAR THE MEXICO BORDER IN THE DESERT SOUTHWEST
AS 500 MB HEIGHTS BECOME ZONAL ACROSS NORTHERN CALIFORNIA. SOME WEAK
SHORTWAVES MAY PASS TO THE NORTH OF CALIFORNIA WEDNESDAY THROUGH
FRIDAY. TEMPERATURES ARE EXPECTED TO FLUCTUATE NEAR NORMAL WITH
THURSDAY AND FRIDAY BEING THE WARMEST DAYS AS RIDGING EXPANDS
NORTHWARD...GENERALLY 2-4 DEGREES ABOVE NORMAL. TEMPS WILL BEGIN A
COOLING TREND...JUST BELOW NORMAL...BY SATURDAY AS A LOW PRESSURE
SYSTEM APPROACHES THE CANADIAN COASTLINE AND ITS ASSOCIATED TROUGH
DIGS SOUTHWARD OVER CALIFORNIA. HAVE KEPT FORECAST DRY DURING TROUGH
PASSAGE SINCE MODELS SHOW PRECIPITATION STAYING TO THE NORTH OR
ALONG THE COAST. JBB
&&
.AVIATION...
VFR CONDS CONTINUE AS FEW TO SCT CUMULUS CLOUDS HAVE DEVELOPED OVER
THE CWA. CLOUD BASES NEAR THE SAC METRO AREA ARE HOVERING AROUND
2500 FT WHILE CLOUDS OVER THE COASTAL...NORTHERN...AND SIERRA MTNS
RANGE AROUND 4000-8000 FT. LIGHT WINDS CONTINUE...GENERALLY 10 KTS
OR LESS IN THE VALLEY...OCCASIONAL MODERATE GUSTS 15 TO 20 KTS IN
UPPER ELEVATIONS AND THROUGH THE DELTA. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KLOX 202100
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PDT SAT SEP 20 2008
.SHORT TERM (TODAY-TUESDAY)...
SOME COLD AIR THAT MOVED OVER THE AREA FROM THE NORTH LAST NIGHT HAS
PRODUCED ABOUT 5C OF COOLING...MOSTLY BETWEEN 950MB AND 800MB. THIS
HAS SEVERELY WEAKENED THE MARINE INVERSION AND IN TURN WEAKENED THE
CONFIDENCE IN THE STRATUS FORECAST. TO THE NORTH...WENT WITH A
SIMILAR COVERAGE PATTERN TO WHAT HAPPENED LAST NIGHT...BUT WOULD NOT
BE SURPRISED TO SEE FAR LESS COVERAGE...ESPECIALLY WHEN FACTORING IN
A BIT OF MORNING NE FLOW. SOUTH OF POINT CONCEPTION...AN EDDY LOOKS
FAVORABLE AND SHOULD DEEPEN THE MARINE LAYER ABOVE 2000 FT. EVEN
THOUGH THAT DEPTH USUALLY BODES WELL FOR A FULL VALLEY ONSLAUGHT...
THE WEAK INVERSION...LACK OF MARINE CLOUD COVERAGE THIS AFTERNOON...
AND NEARBY NORTHERLY FLOW PUTS ANY SCENARIO FROM LITTLE STRATUS OVER
LAND TO FULL VALLEY COVERAGE POSSIBLE. SOMEWHERE IN BETWEEN SEEMS
BEST AT THIS POINT.
THE CENTRAL COAST AND ANTELOPE VALLEY ARE SEEING SOME BREEZY
CONDITIONS THIS AFTERNOON...WHICH SHOULD ABATE EARLY THIS EVENING.
WINDS WILL BE A CONCERN LATER TONIGHT AS WELL...AS WEAK HIGH
PRESSURE FORMS TO THE NORTH. GUSTY NORTHERLY WINDS SHOULD FORM
THROUGH THOSE SUNDOWNER AREAS OF SBA COUNTY AND THE I5 CORRIDOR.
ALTHOUGH NO ADVISORIES ARE EXPECTED AT THIS POINT...SBA COUNTY WILL
GET CLOSE...WITH A FEW CANYONS LIKELY EXCEEDING 35 MPH. SOME
MOISTURE EMBEDDED IN THE FLOW WILL ALSO HELP TO CREATE SOME CLOUDS
ALONG THE NORTH FACING SLOPES.
EVEN THROUGH THE MAINLY ZONAL UPPER PATTERN REMAINS UNCHANGED...
TEMPS WILL BE DIFFICULT TO FORECAST TOMORROW DUE TO THE UNCERTAINTY
IN THE MARINE LAYER. WITH THE CURRENT IDEA OF STRATUS GETTING INTO
THE LA AND VTU VALLEYS TOMORROW...WENT WITH A FEW DEGREES OF
ADDITIONAL COOLING. WITH THE NORTHEAST FLOW AND POSSIBLE DROP IN
STRATUS COVERAGE TO THE NORTH...WENT WITH A FEW DEGREES OF WARMING
UP THERE. MIN TEMPS SHOULD REMAIN RATHER CHILLY LIKE THIS MORNING
FOR AT LEAST ONE MORE NIGHT.
MON AND TUE LOOKS TO KICK OFF AN OVERALL WARM UP AS A TROUGH QUICKLY
PASSES THROUGH THE PAC NW SUN NIGHT AND A HEALTHY 590DM HIGH BUILDS
IN FROM THE SOUTH. PREVIOUS MODELS RUNS HAVE BEEN FLIP FLOPPING...
BUT THE 12Z GFS AND ECMWF ARE CONSISTENT WITH THEIR 0Z COUNTERPARTS
AND CONFIDENCE IS ON THE RISE. NORTHERLY WINDS WILL ABATE ON MON
THANKS TO THE TROUGH PASSAGE TO THE NORTH.
.LONG TERM (WEDNESDAY-SATURDAY)...
WITH ONSHORE GRADS WEAKENING AND THE RIDGE CONTINUING ITS BUILD UP
FROM THE SOUTH...WED AND THU LOOKS TO REMAIN WARM...WITH ONE OF
THOSE DAYS BEING THE WARMEST OF THE WEEK. THE HIGH AND WEAK ONSHORE
GRADS SHOULD KEEP THE MARINE LAYER CONFINED TO THE IMMEDIATE COAST
AT BEST...WHICH FURTHER HINTS AT A WARM MIDWEEK. THERE IS A WILDCARD
IN A WEAK CUTOFF LOW TO THE WEST. THIS PATTERN WILL CREATE AN
EAST-WEST TEMP GRAD THAT MODELS CURRENTLY HAVE US SITTING IN THE
WARM SECTOR WED AND THU...BUT THIS PATTERN COULD SHIFT AND TEMPS
COULD BE A BIT COOLER. NOT ONLY THAT...BUT A WHEN QUESTION EXISTS AS
WELL...AS TO WHEN WILL THINGS FINALLY SHIFT TO THE EAST. CURRENTLY
THE GFS AND ECMWF ARE BEHAVING NICELY...WITH A TROUGH DIGGING INTO
THE LOW TO THE WEST AND PUSHING EVERYTHING EASTWARD ON FRI AND SAT.
THIS IS REFLECTED IN THE FORECAST WITH SOME COOLING...BUT CONFIDENCE
IS LOW THIS FAR OUT.
&&
.AVIATION...20/2000Z.
AN EDDY WILL SPIN UP A MARINE LAYER TONIGHT...BRINGING LOW CLOUDS
AND PATCHY FOG WITH MVFR CONDITIONS TO AT LEAST LA AND VENTURA
COUNTY COASTAL SECTIONS. OF GREATER UNCERTAINTY IS WHETHER THE LOW
CLOUDS AND FOG WILL ALSO SPREAD TO THE SANTA BARBARA SOUTH COAST AND
THE LA COUNTY VALLEY TAF SITES. THE CENTRAL COAST AND KPRB ARE
LIKELY TO HAVE LOW CLOUDS AND FOG WITH MVFR CONDITIONS OVERNIGHT.
KLAX...FAIR TO GOOD CONFIDENCE IN THE CURRENT TAF. CLEAR SKIES UNTIL
07Z WHEN LOW CLOUDS AND PATCHY FOG WILL ARRIVE WITH MVFR CONDITIONS.
A 40 PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AS SOON AS 05Z OR
AS LATE AS 09Z. THEN LOW CLOUDS AND FOG UNTIL LATE MORNING SUNDAY.
KBUR...LITTLE OR NO CONFIDENCE IN THE TAF FORECAST FOR KBUR. A 50
PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AFTER MIDNIGHT...AND A
50 PERCENT CHANCE
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KITTELL
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSGX 202035
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT SAT SEP 20 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. UPPER LEVEL LOW PRESSURE MOVING PAST TO THE NORTH WILL BRING
COOLER WEATHER INTO EARLY NEXT WEEK. LOCALLY WINDY IN THE MOUNTAINS
AND DESERTS AT TIMES. WARMER DURING THE SECOND HALF OF NEXT WEEK
UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
A REVERSE CLEARING PATTERN OCCURRED THIS MORNING WITH THE SAN DIEGO
VALLEYS REMAINING OVERCAST UNTIL 10 AM. THE 12Z KNKX SOUNDING SHOWED
SEVERAL DEGREES OF COOLING BETWEEN THE SURFACE AND 750 MB...AND THIS
HAS DEFINITELY TRANSLATED INTO COOLER WEATHER TODAY. TEMPS AT NOON
WERE ONLY IN THE UPPER 60S AND 70S EVERYWHERE EXCEPT FOR IN THE
DESERTS. PRESSURE GRADIENTS ARE ONSHORE WITH ABOUT 8 MB SAN-TRM AND
6 MB SAN-DAG. THIS IN COMBINATION WITH 15 KT WEST FLOW AT 850 MB HAS
RESULTED IN LOCALLY BREEZY CONDITIONS IN THE MOUNTAINS. EXPECT THE
BREEZY CONDITIONS TO CONTINUE IN THE MOUNTAINS AND ON THE DESERT
SLOPES THROUGH TONIGHT.
A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH THE PACIFIC NORTHWEST
WILL KEEP THE WEATHER MILD ON SUNDAY AS WELL WITH TEMPS GENERALLY
REMAINING AROUND 5 DEGREES BELOW SEASONAL AVERAGES. SLIGHTLY WARMER
ON MONDAY AS HEIGHTS BEGIN TO RISE. THE MARINE LAYER WILL CAUSE
AREAS OF NIGHT/MORNING LOW CLOUDS AND FOG ALONG THE COAST AND IN THE
VALLEYS THROUGH MONDAY.
HIGH PRESSURE BEGINS TO REBUILD OVER NRN BAJA AND SRN CA ON TUE.
TEMPS ARE EXPECTED TO RETURN TO NEAR SEASONAL AVERAGES WITH A
CONTINUATION OF NIGHT/MORNING LOW CLOUDS AND FOG.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
HIGH PRESSURE ALOFT WILL REMAIN OVER SRN CA AND AZ ON THROUGH THU.
THIS WILL BRING WARMING TO THE AREA WITH TEMPS POSSIBLY CLIMBING
INTO THE 90S IN THE INLAND EMPIRE AND EAST COUNTY VALLEYS...AND INTO
THE LOW TO MID 100S IN THE LOWER DESERTS. STRATUS IS EXPECTED TO BE
PATCHY WITH LOW CLOUDS CONFINED TO THE COASTAL AREAS AND WESTERN SAN
DIEGO VALLEYS. NEUTRAL TO WEAK OFFSHORE PRESSURE GRADIENTS FROM THE
NORTH COULD PREVENT THE STRATUS FROM SPREADING INTO INLAND ORANGE
COUNTY SOME MORNINGS. LIMITED MOISTURE IN THE MID LEVELS MAY CAUSE A
FEW CLOUDS TO FORM OVER THE MOUNTAINS ON THU AFTERNOON...BUT NOTHING
OF SIGNIFICANCE. UPPER LEVEL LOW PRESSURE OVER THE PACIFIC COULD
BEGIN TO MOVE TOWARDS THE CA COAST ON FRI/SAT...BRINGING COOLER
WEATHER AND MORE EXTENSIVE MARINE LAYER CLOUDS.
&&
.AVIATION...
202000Z...MARINE LAYER INVERSION WAS AROUND 1900 FT MSL AND SHOULD
LOWER SLIGHTLY TONIGHT. STRATUS WILL BE PATCHY ALONG THE
COAST...MAINLY SAN DIEGO COUNTY...THROUGH 02Z AND THEN FILL IN AND
SPREAD INLAND...EVENTUALLY TO 20 MILES INLAND BY 12Z. BASES AROUND
1500 FT AND TOPS AROUND 2000 FT ARE EXPECTED. CLEARING SHOULD OCCUR
BY 17Z SUN IN MOST AREAS. NO CIG/VIS RESTRICTIONS ARE EXPECTED ABOVE
THE MARINE LAYER.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...SCV
AVIATION/MARINE...MAXWELL
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KLOX 202006
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
100 PM PDT SAT SEP 20 2008
NEW AVIATION DISCUSSION
.SHORT TERM...
A TATTERED MARINE INVERSION IS ALL THAT IS LEFT AFTER SOME COLD AIR
MOVED OVER THE AREA FROM THE NORTH LAST NIGHT. OTHER THAN A FEW
STRANDS OF LOW CLOUDS NEAR THE IMMEDIATE LA AND VTU CO COAST...THE
LACK OF A HEALTHY INVERSION HAS KEPT MOST OF THE AREA SOUTH OF POINT
CONCEPTION CLEAR. THIS ALL HAS HELPED COOL THINGS OFF THIS
MORNING...WITH A SLIGHT CHILL TO THE AIR. TO THE NORTH...THE
NORTHERLY FLOW HAS HELPED STRATUS MOVE DOWN THE COAST FROM MONTEREY
AND COVER A LARGE PORTION OF INTERIOR SLO CO AND THE CENTRAL COAST.
WITH THE WEAK INVERSION...THINGS SHOULD CLEAR OUT FAIRLY QUICKLY.
ALTHOUGH THE CLOUD COVERAGE AND WEAK NORTHERLY FLOW HAS HELPED KEEP
MORNING MONS UP...THE COOLER AIR ALOFT WILL KEEP TEMPS THE SAME OR
COOLER FROM YESTERDAY ACROSS THE ENTIRE REGION. FORECAST TEMPS
REFLECT THIS CHANGE AND LOOK GOOD. WIND-WISE...BREEZY CONDITIONS
EXPECTED THIS AFTERNOON OVER THE CENTRAL COAST...LA MTNS...AND THE
ANTELOPE VALLEY. ALTHOUGH A FEW VERY LOCALIZED SPOTS MAY CLIP
ADVISORY THRESHOLDS...THE MAJORITY OF THESE AREAS WILL REMAIN BELOW.
...FROM PREVIOUS DISCUSSION...
THE UPPER LOW OVER NRN CA WILL OPEN UP AND LIFT NEWD TODAY...BUT A
BROAD UPPER TROUGH WILL LINGER ACROSS THE AREA THROUGH MONDAY
WITH WKLY CYCLONIC FLOW ALF. AT THE SFC DECENT LOW LVL N-S GRADS
SHOULD CAUSE SOME GUSTY WINDS ACROSS THE CENTRAL COAST AGAIN
THIS AFTERNOON...AND WITH GOOD W-E GRADS...STRONG WESTERLY WINDS
SHOULD AFFECT THE ANTELOPE VALLEY. THERE WILL BE ANOTHER ROUND
OF GUSTY WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY
TONIGHT. IT LOOKS AS THOUGH NWLY FLOW WILL BECOME MORE WDSPRD ACROSS
THE MTNS OF L.A./VTU COUNTIES TONIGHT...SO EXPECT LOCALLY STRONG
WINDS NEAR THE INTERSTATE 5 CORRIDOR TONIGHT/SUN MORNING. IT LOOKS
AS THOUGH WINDS WILL REMAIN BELOW ADVISORY LEVELS IN MOST AREAS.
UPSLOPE NLY FLOW SHOULD BRING SOME LOW CLOUDS TO THE NRN SLOPES OF
THE L.A/VTU COUNTY MTNS TONIGHT/SUN MORNING. THE WRF SHOWS A
STRONGER EDDY CRCLN TONIGHT/SUN MORNING...WITH MORE IN THE WAY OF
LOW CLDS/FOG IN CSTL SXNS OF L.A. AND PROBABLY VTU COUNTIES. CLOUDS
SHOULD AGAIN BE FAIRLY WDSPRD ON THE CENTRAL COAST AND IN THE SANTA
YNEZ/SALINAS VALLEYS. WITH THE EDDY CRCLN...SOME CLOUDS MAY PUSH
INTO THE SAN GABRIEL AND POSSIBLY SAN FERNANDO VALLEYS LATE TONIGHT
INTO SUN MORNING. WITH LITTLE CHANGE IN HGTS/THICKNESSES ACROSS THE
AREA ON SUN...EXPECT LITTLE CHANGE IN MAX TEMPS IN THE MTNS AND
DESERTS. ADDITIONAL SLIGHT COOLING AT 950 MB SHOULD BRING SLIGHT
COOLING TO COASTAL AND VALLEY AREAS ON SUNDAY.
THE WRF SHOWS SOMEWHAT WEAKER N-S GRADS AND NWLY LOW LVL FLOW SUN
NIGHT/MON...SO EXPECT LESS IN THE WAY OF WINDS IN THE MTNS AND
ACROSS THE SANTA YNEZ RANGE AND THE SBA COUNTY S CST. THERE MAY BE
SLIGHTLY DEEPER INLAND PENETRATION OF THE STRATUS SUN NIGHT/MON.
WITH HEIGHTS/THICKNESSES BEGINNING TO EDGE UPWARD ON MON...THERE MAY
BE A FEW DEGREES OF WARMING IN THE MTNS AND DESERTS...BUT WITH 950
MB TEMPS CHANGING LITTLE...EXPECT LITTLE CHANGE IN BELOW NORMAL MAX
TEMPS W OF THE MTNS FOR MON.
.LONG TERM...HEIGHTS WILL RISE ACROSS THE AREA TUE AS A FLAT RIDGE
BUILDS ALONG THE W CST. AT THE SAME TIME...LOW LVL ONSHORE GRADS
WILL WEAKEN. EXPECT THE MARINE LAYER TO BECOME MORE SHALLOW MON
NIGHT/TUE...WITH CLOUDS PROBABLY CONFINED TO THE CSTL PLAIN. MAX
TEMPS SHOULD BE UP A FEW DEGREES IN MOST AREAS ON TUE...MOST
NOTICEABLY IN THE VLYS. MODELS ARE A BIT DIFFERENT WITH THE UPPER
PATTERN LATER IN THE WEEK...SPECIFICALLY WITH THE PLACEMENT OF THE
UPPER HIGH WHICH IS NOW FCST TO BE SE OF THE FCST AREA AS OPPOSED TO
RIGHT OVER THE AREA. HEIGHTS ARE STILL RATHER HIGH...AND MODELS
STILL SHOW WEAK OFFSHORE TO NEUTRAL LOW LVL FLOW...AT LEAST WED AND
THU MORNINGS. THEREFORE...STILL EXPECT SIGNIFICANT WARMING ON WED...
ESPECIALLY IN THE VALLEYS...WHERE TEMPS SHOULD RISE WELL INTO THE
90S IN WARMER LOCATIONS...THEN IT WILL CONT TO BE RATHER WARM THU
AND FRI. MARINE LAYER SHOULD BE RATHER MINIMAL IN COVERAGE WED THRU
MORNING...CONFINED MAINLY TO AREAS WITHIN A FEW MILES OF THE CST.
&&
.AVIATION...20/2000Z.
AN EDDY WILL SPIN UP A MARINE LAYER TONIGHT...BRINGING LOW CLOUDS
AND PATCHY FOG WITH MVFR CONDITIONS TO AT LEAST LA AND VENTURA
COUNTY COASTAL SECTIONS. OF GREATER UNCERTAINTY IS WHETHER THE LOW
CLOUDS AND FOG WILL ALSO SPREAD TO THE SANTA BARBARA SOUTH COAST AND
THE LA COUNTY VALLEY TAF SITES. THE CENTRAL COAST AND KPRB ARE
LIKELY TO HAVE LOW CLOUDS AND FOG WITH MVFR CONDITIONS OVERNIGHT.
KLAX...FAIR TO GOOD CONFIDENCE IN THE CURRENT TAF. CLEAR SKIES UNTIL
07Z WHEN LOW CLOUDS AND PATCHY FOG WILL ARRIVE WITH MVFR CONDITIONS.
A 40 PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AS SOON AS 05Z OR
AS LATE AS 09Z. THEN LOW CLOUDS AND FOG UNTIL LATE MORNING SUNDAY.
KBUR...LITTLE OR NO CONFIDENCE IN THE TAF FORECAST FOR KBUR. A 50
PERCENT CHANCE OF LOW CLOUDS AND FOG ARRIVING AFTER MIDNIGHT...AND A
50 PERCENT CHANCE OF CLEAR SKIES.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BRUNO
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 201934 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1230 PM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
DRIER AIR WILL MOVE INTO THE REGION THROUGH THE WEEKEND
...AS AN AREA OF LOW PRESSURE SETTLES ACROSS THE PACIFIC NORTHWEST.
DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY CLEAR SKIES
AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
ISOLATED STORMS DEVELOPED YESTERDAY...POSSIBLY AIDED BY A SHORT WAVE
ASSOCIATED WITH THE UPPER LOW CURRENTLY CENTERED NEAR OR/ID/NV
BORDERS. WATER VAPOR IMAGERY AND PLOT DATA SHOW THE ASSOCIATED JET
AXIS MOVING THROUGH CENTRAL CALIFORNIA AND SOUTHERN NEVADA. THUS
MAIN DYNAMICS STAY WELL TO THE NORTH OF OUR FORECAST AREA. NAM AND
GFS INDICATE A WEAK SHORTWAVE MOVING THROUGH NORTHERN ARIZONA TODAY.
THIS COMBINED WITH LINGERING MOISTURE BEING MAINTAINED BY SOUTHERLY
LOW LEVEL FLOW MAY LEAD TO REDEVELOPMENT OF ISOLATED STORMS OVER THE
LOWER DESERTS EAST OF THE LOWER COLORADO RIVER VALLEY. MADE AN
UPDATE TO THE GRIDS TO SHOW SLIGHT CHANCES OVER PORTIONS OF ZONES
21...22...AND 27. BOTH NAM AND GFS SHOW DRY ADVECTION FROM WEST TO
EAST TODAY AND THUS KEPT POPS VERY LOW AND LIMITED TO LOCATIONS
WHERE STORMS FORMED YESTERDAY...EXCEPT FOR LA PAZ COUNTY WHICH IS
APT TO SEE DRYING SOONER. THEY ALSO SHOW MOISTURE HANGING ON OVER
SOUTH-CENTRAL ARIZONA SUNDAY INTO MONDAY. MAY NEED TO RAISE POPS FOR
ZONE 24 IN THE AFTERNOON PACKAGE. WILL CONTINUE TO EVALUATE.
OTHERWISE MADE ONLY SUBTLE FIRST PERIOD UPDATES.
PREVIOUS DISCUSSION...
TODAY...HIGH PRESSURE RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO
FLATTEN/WEAKEN IN RESPONSE TO A TROUGH OF LOW PRESSURE MOVING
ONSHORE NRN CA EARLY THIS MORNING. BEST DYNAMICS AND FORCING
ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL TO OUR NORTH...WHILE A
DRY WEST/SOUTHWESTERLY FLOW CONTINUES OVER OUR AREA. 24 HOUR CHANGE
PRODUCT INDICATES DEW POINTS OUT WEST HAVE DROPPED ABOUT 10 DEG
FROM THIS TIME YESTERDAY...AND THE DRIER CONDITIONS SHOULD LEAD TO
SLIGHTLY COOLER MORNING LOWS TODAY COMPARED TO FRIDAY.
FOR THE REMAINDER OF THE WEEKEND...DRIER AIR WILL CONTINUE TO SPREAD
WEST TO EAST ACROSS SOUTHEAST CA...SOUTHWEST AND SOUTH-CENTRAL
AZ...WITH LITTLE TO NO THREAT FOR SHOWERS/TSTMS. MEANWHILE...WE`LL
SEE LITTLE DAY TO DAY CHANGE IN TEMPS...WITH HIGHS AND LOWS
CONTINUING TO RUN A FEW DEG ABOVE NORMAL FOR MID/LATE SEPTEMBER.
MONDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
MID LEVEL MSTR BLO 15 THSD FT REMAINED IN PLACE THIS MORNING BENEATH
A SHARP INVRN...PER PSR SOUNDING. CLOUDS BTWN 9 AND 12 THSD FT AT
SKY HARBOR WILL LIKELY DECREASE BY 02Z. SFC WNDS WILL ALSO DROP
OFF BY 03Z...VEER SLOWLY...AND BECOME LIGHT/EASTERLY.
NO AVIATION CONCERNS FOR LOWER COLORADO RIVER VALLEY OR KIPL
TAFS...ALTHO OCNL GUSTY WINDS ARE STILL PSBL AT KIPL AND KBLH THRU
03Z THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MOSTLY CLEAR SKIES WITH DRY CONDITIONS ARE EXPECTED THROUGH THE
EXTENDED. WINDS WILL INCREASE SUNDAY EVENING AND AGAIN
MONDAY...AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH THE PAC NW.
RH VALUES ARE EXPECTED TO DIP BELOW CRITICAL LEVELS ACROSS THE
SOUTHEAST CALIFORNIA DESERTS BY SUNDAY AFTERNOON...BUT SHOULD REMAIN
ABOVE CRITICAL LEVELS ELSEWHERE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...SIPPLE
FIRE WEATHER...WANEK
000
FXUS65 KREV 201909 AAA
AFDREV
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
1153 AM PDT SAT SEP 20 2008
.UPDATE...
QUICK UPDATE TO ADD ISOLD -SHRA TO THE FAR NWRN NV AND SURPRISE
VALLEY THIS AFTERNOON AS MOISTURE WRAPPING AROUND BACK SIDE OF
UPPER LOW IS INCREASING WITH A FEW WEAK RADAR ECHOES IN CNTRL
MODOC COUNTY PUSHING SOUTHEAST. MOST SHOWERS WILL ONLY PRODUCE
TRACE AMOUNTS OF PRECIP AND LIGHTNING IS NOT EXPECTED DUE TO
MARGINAL INSTBY. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 230 AM PDT SAT SEP 20 2008/
SHORT TERM...
UPPER LOW OVER NERN CA-NW NV WILL LIFT NORTHEAST INTO OR/ID TODAY.
ISOLD SHOWERS AND AN OCCASIONAL TSTM AHEAD OF THIS LOW ARE STILL
ONGOING OVER PERSHING COUNTY/FAR NRN WASHOE COUNTY...BUT THESE
SHOULD MOVE NORTH OF THE AREA NEAR SUNRISE. DRIER WEST TO NORTHWEST
FLOW WILL DOMINATE THE AREA OVER THE WEEKEND...ALTHOUGH WEAK SHORT
WAVES WILL MOVE ACROSS THE AREA TODAY AND SUNDAY BRINGING PERIODS OF
CLOUDS ACROSS THE AREA. TEMPERATURES WILL REMAIN JUST BELOW
NORMAL...WITH HIGHS IN THE UPPER 70S TO LOW 80S IN WRN NV AND IN THE
LOW 70S IN THE SIERRA.
A STRONGER SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW MOVES ACROSS
THE CWA SUNDAY NIGHT INTO MONDAY MORNING. SOME MOISTURE IS
ASSOCIATED WITH THE SHORT WAVE...BUT IT LOOKS TO ONLY GENERATE
CLOUDS ACROSS THE NRN HALF OF THE AREA. MOST MID LEVEL MOISTURE AND
INSTABILITY REMAINS JUST NORTH OF THE NV-OR BORDER. THEREFORE THE
FORECAST WILL REMAIN DRY FOR NOW...BUT CANNOT RULE OUT A FEW SHOWERS
NEAR THE OREGON BORDER. THE SHORT WAVE WILL ALSO BRING IN SLIGHTLY
COOLER WEATHER WITH TEMPERATURES LOWERING A COUPLE DEGREES BY
MONDAY. OTHERWISE DRY CONDITIONS ARE EXPECTED ON MONDAY. GMCGUIRE
LONG TERM...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE WILL BRING DRY CONDITIONS WITH ABOVE NORMAL
TEMPERATURES TO THE EASTERN SIERRA AND WESTERN NV DURING THE PERIOD.
STORM ENERGY REMAINS WELL NORTH OF NV ALTHOUGH SHORTWAVES MOVING BY
DRAG SOME HIGH LEVEL MOISTURE AND BRING LOCAL GUSTY WINDS TO THE
NORTHERN ZONES ON WEDNESDAY. A WEAK TROUGH DEVELOPS OVER THE EASTERN
PACIFIC ON FRIDAY AND TURNS THE FLOW A LITTLE MORE SOUTHERLY. THE
ECMWF SHOWS 500MB MOISTURE OVER MONO AND MINERAL COUNTIES FRIDAY
AFTERNOON WHILE THE GFS IS DRIER AND STABLE ALTHOUGH PRECIPITABLE
WATER VALUES CLIMB ABOVE A HALF INCH. WILL CONTINUE THE ON-GOING
FORECAST OF SUNNY AND DRY...WITH SOME INCREASED CLOUD COVER AND LOW
POPS. RC
AVIATION...
VFR CONDITIONS EXPECTED THROUGH 12Z SUNDAY. ISOLD -SHRA NORTHEAST OF
KLOL WILL DISSIPATE OR MOVE WELL AWAY FROM THE AREA BY 15Z. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS65 KREV 201853 AAA
AFDREV
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
1153 AM PDT SAT SEP 20 2008
.UPDATE...
QUICK UPDATE TO ADD ISOLD -SHRA TO THE FAR NWRN NV AND SURPRISE
VALLEY THIS AFTERNOON AS MOISTURE WRAPPING AROUND BACK SIDE OF
UPPER LOW IS INCREASING WITH A FEW WEAK RADAR ECHOES IN CONTROL
MODOC COUNTY PUSHING SOUTHEAST. MOST SHOWERS WILL ONLY PRODUCE
TRACE AMOUNTS OF PRECIP AND LIGHTNING IS NOT EXPECTED DUE TO
MARGINAL INSTBY. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 230 AM PDT SAT SEP 20 2008/
SHORT TERM...
UPPER LOW OVER NERN CA-NW NV WILL LIFT NORTHEAST INTO OR/ID TODAY.
ISOLD SHOWERS AND AN OCCASIONAL TSTM AHEAD OF THIS LOW ARE STILL
ONGOING OVER PERSHING COUNTY/FAR NRN WASHOE COUNTY...BUT THESE
SHOULD MOVE NORTH OF THE AREA NEAR SUNRISE. DRIER WEST TO NORTHWEST
FLOW WILL DOMINATE THE AREA OVER THE WEEKEND...ALTHOUGH WEAK SHORT
WAVES WILL MOVE ACROSS THE AREA TODAY AND SUNDAY BRINGING PERIODS OF
CLOUDS ACROSS THE AREA. TEMPERATURES WILL REMAIN JUST BELOW
NORMAL...WITH HIGHS IN THE UPPER 70S TO LOW 80S IN WRN NV AND IN THE
LOW 70S IN THE SIERRA.
A STRONGER SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW MOVES ACROSS
THE CWA SUNDAY NIGHT INTO MONDAY MORNING. SOME MOISTURE IS
ASSOCIATED WITH THE SHORT WAVE...BUT IT LOOKS TO ONLY GENERATE
CLOUDS ACROSS THE NRN HALF OF THE AREA. MOST MID LEVEL MOISTURE AND
INSTABILITY REMAINS JUST NORTH OF THE NV-OR BORDER. THEREFORE THE
FORECAST WILL REMAIN DRY FOR NOW...BUT CANNOT RULE OUT A FEW SHOWERS
NEAR THE OREGON BORDER. THE SHORT WAVE WILL ALSO BRING IN SLIGHTLY
COOLER WEATHER WITH TEMPERATURES LOWERING A COUPLE DEGREES BY
MONDAY. OTHERWISE DRY CONDITIONS ARE EXPECTED ON MONDAY. GMCGUIRE
LONG TERM...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE WILL BRING DRY CONDITIONS WITH ABOVE NORMAL
TEMPERATURES TO THE EASTERN SIERRA AND WESTERN NV DURING THE PERIOD.
STORM ENERGY REMAINS WELL NORTH OF NV ALTHOUGH SHORTWAVES MOVING BY
DRAG SOME HIGH LEVEL MOISTURE AND BRING LOCAL GUSTY WINDS TO THE
NORTHERN ZONES ON WEDNESDAY. A WEAK TROUGH DEVELOPS OVER THE EASTERN
PACIFIC ON FRIDAY AND TURNS THE FLOW A LITTLE MORE SOUTHERLY. THE
ECMWF SHOWS 500MB MOISTURE OVER MONO AND MINERAL COUNTIES FRIDAY
AFTERNOON WHILE THE GFS IS DRIER AND STABLE ALTHOUGH PRECIPITABLE
WATER VALUES CLIMB ABOVE A HALF INCH. WILL CONTINUE THE ON-GOING
FORECAST OF SUNNY AND DRY...WITH SOME INCREASED CLOUD COVER AND LOW
POPS. RC
AVIATION...
VFR CONDITIONS EXPECTED THROUGH 12Z SUNDAY. ISOLD -SHRA NORTHEAST OF
KLOL WILL DISSIPATE OR MOVE WELL AWAY FROM THE AREA BY 15Z. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KEKA 201755 AAA
AFDEKA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE EUREKA CA
1055 AM PDT SAT SEP 20 2008
.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD OVER NORTHERN CALIFORNIA
TODAY AND HOLD THROUGH MIDDAY SUNDAY BEFORE WEAKENING. INCREASING
CLOUDS ARE EXPECTED LATE SUNDAY NIGHT AS A WEAK UPPER LEVEL TROUGH
MOVES ACROSS THE REGION.
&&
.UPDATE...MORNING VISIBLE SATELLITE IMAGERY SHOWS FAIRLY EXTENSIVE
LOW CLOUDS OVER THE WESTERN TWO THIRDS OF THE CWA. SKIES WILL
GRADUALLY BECOME PARTLY CLOUDY OVER THE INTERIOR THROUGH THE DAY
WITH SOME PARTIAL CLEARING EXPECTED FOR THE REDWOOD COAST AS WELL.
HAVE ISSUED AN UPDATE TO ACCOUNT FOR HIGHER CLOUD COVER AND
ASSOCIATED COOLER DAYTIME HIGHS FOR TODAY. KL
&&
.SHORT TERM...TODAY THROUGH MONDAY...THE GFS AND ECMWF MODELS ARE
IN GOOD AGREEMENT DURING THIS TIME PERIOD. OVERNIGHT...WIDESPREAD
SC CEILINGS AND AREAS OF VALLEY FOG WAS INDICATED BY SATELLITE
IMAGERY. AS THE TROUGH LIFTS TO THE NORTHEAST AND WEAK RIDGING
BUILDS OVER NORTHERN CALIFORNIA...THE CLOUDS WILL GRADUALLY BECOME
SCATTERED AND FOR INLAND LOCATIONS...THE SKIES WILL BECOME CLEAR.
THIS WILL MEAN A WARMING AND DRYING TREND FOR THE INTERIOR. THE
COAST WILL REMAIN UNDER THE INFLUENCE OF THE MARINE LAYER...AND
THE LOW CLOUDS AND PATCHY FOG WILL RETURN SATURDAY NIGHT INTO
SUNDAY MORNING. SUNDAY NIGHT A WEAK TROUGH WILL MOVE ACROSS THE
REGION. OTHER THAN AN INCREASE IN CLOUDS...NO WEATHER IS EXPECTED.
MONDAY A SLIGHTLY STRONGER RIDGE WILL BUILD AND MOVE ACROSS THE
REGION. KENNEDY
.LONG TERM...TUESDAY THROUGH FRIDAY...THE UPPER LEVEL RIDGE WILL
MOVE TO THE EAST AS AN UPPER LEVEL TROUGH APPROACHES THE PACIFIC
NORTHWEST. THE INLAND WARMING TREND WILL CONTINUE THROUGH TUESDAY.
THE MODELS DIFFER ON THE STRENGTH OF THIS TROUGH. THE ECMWF HAD A
DEEPER TROUGH AND EXTENDED THE PRECIPITATION FURTHER SOUTH THAN THE
GFS MODEL. AS A COMPROMISE...DID INCREASE THE POPS TO SLIGHT CHANCE
OF PRECIPITATION FOR WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT
NORTH OF KLAMATH. THE WEAK COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL BRING COOLER TEMPERATURES TO THE NORTHERN HALF OF THE CWA. THEN
FOR THURSDAY AND FRIDAY A WEAK RIDGE BUILD OVER THE REGION...
BRINGING A DRY PATTERN AND SEASON TEMPERATURES. THE ABSENCE OF A
STRONG OFFSHORE FLOW WILL CONTINUE THE USUAL REGIMEN OF LATE NIGHT
AND EARLY MORNING LOW CLOUDS ALONG THE COAST WITH PARTIAL CLEARING
EACH AFTERNOON. KENNEDY
&&
.AVIATION...CIGS EARLY THIS MORNING CONTINUE TO REMAIN
VFR...GENERALLY BETWEEN 030 AND 050 ACROSS THE REGION. THOUGH NO
SITES HAVE REPORTED ANY LOWERED VSBYS YET...WITH YESTERDAYS LIGHT
PRECIP ACROSS THE REGION...MOST AREAS CAN EXPECT SOME BRIEF PATCHY
MVFR FOG AROUND SUNRISE...ESPECIALLY IN VALLEY LOCATIONS AND ALONG
THE COAST.
LIGHT AND VARIABLE WINDS THIS MORNING WILL SHIFT TO THE N AND NW BY
THE AFTERNOON HOURS AS HIGH PRESSURE STRENGTHENS OVER THE EAST
PACIFIC. WITH FLOW REMAINING GENERALLY LIGHT THROUGH THIS
AFTERNOON...ITS LIKELY THAT SCT-BKN 030-050 CIGS WILL CONTINUE
THROUGH THE DAY ESPECIALLY OVER COASTAL HILLS. ALM
&&
.MARINE...W-NW SWELL TRAIN BEHIND THE UPPER LOW PASSAGE CONTINUES TO
AFFECT THE REGION WITH SEAS RUNNING BETWEEN 4 TO 6 FT THIS MORNING.
WAVE RIDER BUOYS CONTINUE TO SHOW A SOUTHERLY SWELL OF 2 TO 3 FT
MOVING THROUGH THE WATERS. SEAS WILL PEAK THIS MORNING AT THEIR
CURRENT HEIGHTS AND GRADUALLY SUBSIDE THROUGH THE REMAINDER OF THE
DAY BACK DOWN TO 2 TO 3 FT...WITH SEAS REMAINING MIXED AS SOUTHERLY
SWELL CONTINUES.
N-NW WINDS WILL INCREASE THROUGH THE DAY AS HIGH PRESSURE BUILDS
OVER THE EAST PACIFIC. WINDS ARE EXPECTED TO INCREASE TO SCA LEVELS
OVER THE OUTER WATERS LATER ON SUNDAY AS STRONGER HIGH PRESSURE
BUILDS INTO THE PAC NW BEHIND ANOTHER WEAK FRONT. MODELS HAVE BEEN
INCONSISTENT WITH STRENGTH OF WINDS IN THE MON-WED TIME FRAME...BUT
SFC PRESSURE PATTERN CONTINUES TO LOOKS GOOD FOR HIGH END SCA
CONDITIONS AND HAVE CONTINUED TO INDICATED GALE FORCE GUSTS FOR THE
OUTER WATERS. SCA CONDITIONS ARE EXPECTED TO CONTINUE OVER THE OUTER
COASTAL WATERS THROUGH THE MIDDLE OF NEXT WEEK. ALM
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS65 KPSR 201740
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1040 AM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...
DRIER AIR WILL MOVE INTO THE REGION THROUGH THE WEEKEND
...AS AN AREA OF LOW PRESSURE SETTLES ACROSS THE PACIFIC NORTHWEST.
DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY CLEAR SKIES
AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
ISOLATED STORMS DEVELOPED YESTERDAY...POSSIBLY AIDED BY A SHORT WAVE
ASSOCIATED WITH THE UPPER LOW CURRENTLY CENTERED NEAR OR/ID/NV
BORDERS. WATER VAPOR IMAGERY AND PLOT DATA SHOW THE ASSOCIATED JET
AXIS MOVING THROUGH CENTRAL CALIFORNIA AND SOUTHERN NEVADA. THUS
MAIN DYNAMICS STAY WELL TO THE NORTH OF OUR FORECAST AREA. NAM AND
GFS INDICATE A WEAK SHORTWAVE MOVING THROUGH NORTHERN ARIZONA TODAY.
THIS COMBINED WITH LINGERING MOISTURE BEING MAINTAINED BY SOUTHERLY
LOW LEVEL FLOW MAY LEAD TO REDEVELOPMENT OF ISOLATED STORMS OVER THE
LOWER DESERTS EAST OF THE LOWER COLORADO RIVER VALLEY. MADE AN
UPDATE TO THE GRIDS TO SHOW SLIGHT CHANCES OVER PORTIONS OF ZONES
21...22...AND 27. BOTH NAM AND GFS SHOW DRY ADVECTION FROM WEST TO
EAST TODAY AND THUS KEPT POPS VERY LOW AND LIMITED TO LOCATIONS
WHERE STORMS FORMED YESTERDAY...EXCEPT FOR LA PAZ COUNTY WHICH IS
APT TO SEE DRYING SOONER. THEY ALSO SHOW MOISTURE HANGING ON OVER
SOUTH-CENTRAL ARIZONA SUNDAY INTO MONDAY. MAY NEED TO RAISE POPS FOR
ZONE 24 IN THE AFTERNOON PACKAGE. WILL CONTINUE TO EVALUATE.
OTHERWISE MADE ONLY SUBTLE FIRST PERIOD UPDATES.
PREVIOUS DISCUSSION...
TODAY...HIGH PRESSURE RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO
FLATTEN/WEAKEN IN RESPONSE TO A TROUGH OF LOW PRESSURE MOVING
ONSHORE NRN CA EARLY THIS MORNING. BEST DYNAMICS AND FORCING
ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL TO OUR NORTH...WHILE A
DRY WEST/SOUTHWESTERLY FLOW CONTINUES OVER OUR AREA. 24 HOUR CHANGE
PRODUCT INDICATES DEW POINTS OUT WEST HAVE DROPPED ABOUT 10 DEG
FROM THIS TIME YESTERDAY...AND THE DRIER CONDITIONS SHOULD LEAD TO
SLIGHTLY COOLER MORNING LOWS TODAY COMPARED TO FRIDAY.
FOR THE REMAINDER OF THE WEEKEND...DRIER AIR WILL CONTINUE TO SPREAD
WEST TO EAST ACROSS SOUTHEAST CA...SOUTHWEST AND SOUTH-CENTRAL
AZ...WITH LITTLE TO NO THREAT FOR SHOWERS/TSTMS. MEANWHILE...WE`LL
SEE LITTLE DAY TO DAY CHANGE IN TEMPS...WITH HIGHS AND LOWS
CONTINUING TO RUN A FEW DEG ABOVE NORMAL FOR MID/LATE SEPTEMBER.
MONDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
NO AVIATION CONCERNS FOR THE NEXT FEW DAYS. IN THE PHOENIX METRO
AREA...WINDS WILL REMAIN LIGHT AND EXHIBIT TYPICAL
UP-VALLEY/DOWN-VALLEY PATTERNS. FURTHER WEST NEAR
KYUM/KBLH/KIPL...WINDS WILL GENERALLY BE OUT OF THE SOUTH BEFORE
ACQUIRING MORE OF A WESTERLY COMPONENT AFTER 00Z SUN AS A TROUGH
MOVES INTO SOUTHERN CA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MOSTLY CLEAR SKIES WITH DRY CONDITIONS ARE EXPECTED THROUGH THE
EXTENDED. WINDS WILL INCREASE SUNDAY EVENING AND AGAIN
MONDAY...AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH THE PAC NW.
RH VALUES ARE EXPECTED TO DIP BELOW CRITICAL LEVELS ACROSS THE
SOUTHEAST CALIFORNIA DESERTS BY SUNDAY AFTERNOON...BUT SHOULD REMAIN
ABOVE CRITICAL LEVELS ELSEWHERE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...HIRSCH
FIRE WEATHER...WANEK
000
FXUS66 KMTR 201655
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
955 AM PDT SAT SEP 20 2008
UPDATED AVIATION DISCUSSION
.DISCUSSION...AS OF 8:20 AM PDT SATURDAY...THE WEAK FRONT THAT
PRODUCED LIGHT RAIN IN THE NORTH BAY ON FRIDAY SPREAD SIGNIFICANT
LOW LEVEL MOISTURE ACROSS THE REGION OVERNIGHT. THAT MOISTURE AND
SOME LIFT COMBINED TO PRODUCE WIDESPREAD DRIZZLE NEAR THE COAST
OVERNIGHT...ENOUGH TO MEASURE IN SOME SPOTS PARTICULARLY NEAR
MONTEREY BAY. LOW CLOUDS CURRENTLY BLANKET MOST OF OUR CWA AND LOW
LEVEL MIXING IS POOR THIS MORNING. HOWEVER...THE CLOUD LAYER APPEARS
TO BE RELATIVELY THIN AND SHOULD CLEAR IN MOST INLAND AREAS BY LATE
MORNING. SOME PATCHES OF LOW CLOUDS WILL LIKELY LINGER NEAR THE
OCEAN WELL INTO THE AFTERNOON HOURS. TEMPERATURES WILL REMAIN COOLER
THAN NORMAL INLAND. COASTAL AREAS WILL HAVE COOLER TEMPS COMPARED
TO FRIDAY...BUT COULD STILL WARM TO NEAR NORMAL DEPENDING ON THE
AMOUNT OF AFTERNOON SUN.
THE LOW LEVELS WILL GRADUALLY DRY OVER THE NEXT 36 HOURS AS THE
FLOW VEERS MORE TO THE NORTH. BUT AREAS OF LOW CLOUDS WILL CONTINUE
THROUGH AT LEAST MIDDAY SUNDAY. BETTER LOW LEVEL MIXING WILL KICK IN
LATE SUNDAY INTO MONDAY AFTER A SHORTWAVE TROUGH PASSES INLAND TO
OUR NORTH. THIS MIXING WILL DRY OUT THE LOW LEVELS AND PRODUCE
MOSTLY SUNNY SKIES IN ALL AREAS EARLY NEXT WEEK. PLENTY OF SUN...
COMBINED WITH A WARMING AIRMASS UNDER A FLAT UPPER RIDGE...WILL
RESULT IN A GOOD WARM-UP ON MONDAY. TEMPERATURES SHOULD WARM BACK TO
NORMAL THAT DAY AND THEN REMAIN AT OR SLIGHTLY ABOVE NORMAL THROUGH
MUCH OF NEXT WEEK. SUCH A SCENARIO WILL VERIFY IF THE 06Z GFS IS
CORRECT. HOWEVER...COMPARED TO THE GFS THE 00Z ECMWF FORECASTS A
MORE ROBUST TROUGH MOVING THROUGH THE PAC NW AROUND MIDWEEK...WHICH
WOULD HALT ANY WARMING TREND AND PERHAPS LEAD TO SLIGHT MID
WEEK COOLING. WILL WAIT FOR THE 12Z MODEL RUNS BEFORE MAKING ANY
ADJUSTMENTS TO TEMPS NEXT WEEK.
&&
.AVIATION...AS OF 9:55 AM PDT SATURDAY...MVFR CIGS IN LOW CLOUD DECK
STARTING TO LIFT AS ATMOSPHERE STARTS A SLOW DRYING PROCESS TODAY.
CIGS WILL CONTINUE TO LIFT THROUGHOUT THE DAY WITH BASES AT OR ABOVE
3500 FT AFTER 12 NOON. MOST AREAS SHOULD SCATTER OUT BY LATE IN THE
AFTERNOON. EARLY EVENING VFR WITH SOME SCT DECKS ABOVE 3500 FT MSL.
HOWEVER...EXPECT THE MARINE LAYER TO REFORM AND MVFR CIGS TO DEVELOP
BY LATE EVENING...AND THE STRATUS TO MAKE A WEAK PUSH INLAND
OVERNIGHT INTO ONLY THE LOWER INTERMEDIATE VALLEYS...THAT IS LOWER
SALINAS VALLEY AND AROUND S.F.BAY. MODEL FORECAST ONSHORE GRADIENTS
APPEAR TO BE WEAK AND THE MARINE LAYER IS EXPECTED TO RANGE 1300 TO
1700 FT DEEP.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
THIS AFTERNOON
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSTO 201641
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
940 AM PDT SAT SEP 20 2008
.DISCUSSION...
MAIN UPPER LOW CONTINUES TO LIFT OFF TO THE NORTHEAST INTO THE
NORTHERN ROCKIES TODAY WHILE ANOTHER SHORTWAVE TROUGH FOLLOWING
QUICKLY ON ITS HEELS WILL MOVE THROUGH NORTHERN CALIFORNIA TODAY.
RIDGING EXPECTED TO BRIEFLY BUILD TONIGHT BEFORE ANOTHER SHORTWAVE
(PRESENTLY MOVING INSIDE OF 150W) MOVES ONSHORE ON SUNDAY. BEHIND
THAT WAVE...DRIER NORTHERLY FLOW IS EXPECTED TO DEVELOP SUNDAY NIGHT
AND MONDAY AS THE UPPER RIDGE AMPLIFIES A BIT OVER THE EASTERN
PACIFIC.
PER MORNING SOUNDINGS AND SATELLITE IMAGERY...QUITE A BIT OF
LOW-LEVEL MOISTURE REMAINS...THOUGH PROBABLY NOT DEEP ENOUGH FOR ANY
SHOWERS TODAY. FORECAST SOUNDINGS SHOW LCL/S LIFTING DURING THE
AFTERNOON...BUT LITTLE IF ANY CAPE IS FORECAST. BETTER LARGE-SCALE
LIFT AND SOME INSTABILITY FORECAST ACROSS THE NORTHERN MOUNTAINS ON
SUNDAY AFTERNOON AND EVENING AS SECOND UPSTREAM SHORTWAVE
APPROACHES...SO MAY CONSIDER ADDING SLIGHT CHANCE POPS FOR THAT AREA.
UPDATES OUT SHORTLY TO INCREASE CLOUD COVER AND SHAVE TEMPERATURES A
BIT FOR MAINLY HIGHER TERRAIN FOR THIS AFTERNOON.
&&
.AVIATION...
VFR CONDS FOR MOST OF THE CWA TODAY. FEW-SCT CLOUDS ACROSS NORCAL
ABOUT 6000-8000 FT OVER THE NORTHERN SAC VALLEY AS STRATO CU DVLPS
OVER THE NORTHERN MTNS. AREAS OF FOG REMAIN IN THE CENTRAL AND SRN
SAC VALLEY INTO THE NRN SAN JOAQUIN VALLEY...WHERE MVFR CIGS RANGE
1500-2000 FT. KSMF...KSAC...KMHR...AND KSCK ARE JUST WEST OF A LARGE
PATCH OF VALLEY STRATUS. RECENT SATELLITE IMAGERY SUGGESTS THAT ONLY
KMHR AND KSCK MAY BE AFFECTED OVER THE NEXT FEW HOURS SINCE THE
NORTHERN EDGE OF THE STRATUS IS ERODING SOUTHWARD. LGT WINDS TDA...
GENERALLY 10 KTS OR LESS IN THE VALLEY...OCNL MODERATE GUSTS UP TO
20 KTS IN UPPER ELEVATIONS. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 201625
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
925 AM PDT SAT SEP 20 2008
.DISCUSSION...UPPER AIR PATTERN HAS A NEGATIVELY TILTED TROUGH
OVER THE WEST COAST THIS MORNING WITH AN AREA OF DIFLUENCE OVER
THE UPPER GREAT BASIN. THIS TROUGH PATTERN WILL KEEP MOST OF THE
ACTIVE WEATHER TO THE EAST AND NORTH OF THE DISTRICT. OVER CENTRAL
CALIFORNIA...A +70KT JET IN A ZONAL FLOW PATTERN IS INTRODUCING A
COOL AND STABLE AIRMASS TODAY. AFTER A VERY COOL MORNING...
TEMPERATURES MAY HAVE A DIFFICULT TIME REACHING THE 80S OVER THE
VALLEY AS SOME LOCATIONS MAY ONLY SEE THE UPPER 70S. CURRENT
FORECAST ON TRACK WITH THIS MORNING/S ANALYSIS...SO NO UPDATES
NEEDED DURING THE FIRST PERIOD. SHORT RANGE MODELS SHOW THE ZONAL
FLOW REMAINING IN PLACE THROUGH SUNDAY WITH EMBEDDED WEAK SHORT
WAVE TROF/S MOVING THROUGH THE MAIN FLOW. THIS PATTERN WILL OFFER
LITTLE CHANGE OVER THE WEEKEND AS COOL CONDITIONS PERSIST UNTIL
EARLY NEXT WEEK.
BEYOND SUNDAY...AN UPPER RIDGE IS STILL EXPECTED TO BUILD IN FROM
THE SOUTHWEST AND INTRODUCE A WARMING TREND BEGINNING EARLY NEXT
WEEK. THIS WARMING TREND WILL CONTINUE THROUGH MOST OF THE WEEK
AS THE RIDGE BECOMES THE DOMINATE FEATURE OVER THE WEST.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA
INTERIOR THROUGH 18Z SUNDAY.
&&
.AIR QUALITY ISSUES...ON SATURDAY SEPTEMBER 20 2008...
UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO... KERN AND TULARE
COUNTIES. FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...SANGER
WEATHER.GOV/HANFORD
000
FXUS66 KSGX 201623
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 AM PDT SAT SEP 20 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. UPPER LEVEL LOW PRESSURE MOVING PAST TO THE NORTH WILL BRING
COOLER WEATHER INTO EARLY NEXT WEEK. LOCALLY WINDY IN THE MOUNTAINS
AND DESERTS AT TIMES. WARMER DURING THE SECOND HALF OF NEXT WEEK
UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH MONDAY)...
STRATUS REMAINED SPARSE EARLY THIS MORNING THEN FINALLY SURGED
INLAND AROUND SUNRISE. 12Z KNKX SOUNDING PLACES THE BASE OF THE
MARINE INVERSION AT 1700 FT...AT LEAST 700 FT HIGHER THAN YESTERDAY
MORNING...AND IT CONTINUES TO RISE. THERE HAS ALSO BEEN SEVERAL
DEGREES OF COOLING BETWEEN THE SURFACE AND 750 MB (8400 FT)...AND
THIS SHOULD TRANSLATE INTO COOLER WEATHER FOR MUCH OF THE AREA
TODAY. PRESSURE GRADIENTS ARE ONSHORE WITH ABOUT 6 MB SAN-TRM AND 4
MB SAN-DAG. THIS IN COMBINATION WITH 15 KT WEST FLOW AT 850 MB HAS
RESULTED IN BREEZY CONDITIONS THROUGH SOME MOUNTAIN PASSES THIS
MORNING. EXPECT THE BREEZY CONDITIONS TO CONTINUE IN THE MOUNTAINS
AND ON THE DESERT SLOPES THROUGH TONIGHT.
A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH THE PACIFIC NORTHWEST
WILL KEEP THE WEATHER MILD THROUGH THE WEEKEND WITH TEMPS GENERALLY
REMAINING AROUND 5 DEGREES BELOW SEASONAL AVERAGES. THE MARINE LAYER
WILL CAUSE AREAS OF NIGHT/MORNING LOW CLOUDS AND FOG ALONG THE COAST
AND IN THE VALLEYS THROUGH MONDAY.
&&
.LONG TERM (TUESDAY THROUGH FRIDAY)...
HIGH PRESSURE SHOULD BUILD OVER SRN CA AND AZ ON TUE...AND REMAIN
OVER OR JUST TO THE EAST OF THE FORECAST AREA THROUGH FRI. HEIGHTS
AND THICKNESS VALUES INCREASE TUE/WED...AND 850 MB TEMPS ARE
FORECAST TO INCREASE FROM AROUND 20C OVER THE VALLEYS ON TUE TO
BETWEEN 23-25C BY WED. THIS WILL BRING WARMING TO SRN CA WITH TEMPS
CLIMBING BACK INTO THE 90S IN THE INLAND EMPIRE AND EAST COUNTY
VALLEYS...AND LOW TO MID 100S IN THE LOWER DESERTS. STRATUS IS
EXPECTED TO BE PATCHY WITH LOW CLOUDS CONFINED TO THE COASTAL AREAS
AND WESTERN SAN DIEGO VALLEYS. NEUTRAL TO WEAK OFFSHORE PRESSURE
GRADIENTS FROM THE NORTH COULD PREVENT THE STRATUS FROM SPREADING
INTO INLAND ORANGE COUNTY. SIMILAR WEATHER ON THU/FRI AS UPPER LEVEL
HIGH PRESSURE REMAINS OVER/NEAR THE AREA.
&&
.AVIATION...
201540Z...MARINE LAYER INVERSION/STRATUS BASE IS NOW AROUND 2000 FT
MSL WITH TOPS TO 2500 FT. MOST OF THE STRATUS IS IN SAN DIEGO COUNTY
AND SHOULD ACTUALLY GO FROM BKN TO SCT NEAR THE COAST BEFORE INLAND
AREAS. TIMING IN SAN DIEGO COUNTY WILL RANGE FROM 16Z-17Z NEAR THE
COAST TO 18Z-19Z OVER THE INLAND VALLEYS...AND SCT CONDITIONS WILL
CONTINUE AT LEAST THROUGH EARLY AFTERNOON. CLEARING WILL BE
FASTER...GENERALLY BY 17Z...IN ORANGE COUNTY. THE MARINE LAYER WILL
LOWER SLIGHTLY TONIGHT WITH BASES AROUND 1500 FT AND TOPS AROUND
2000 FT. NO CIG/VIS RESTRICTIONS ARE EXPECTED ABOVE THE MARINE LAYER.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...SCV
AVIATION/MARINE...MAXWELL
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KLOX 201555
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
900 AM PDT SAT SEP 20 2008
.SHORT TERM...
A TATTERED MARINE INVERSION IS ALL THAT IS LEFT AFTER SOME COLD AIR
MOVED OVER THE AREA FROM THE NORTH LAST NIGHT. OTHER THAN A FEW
STRANDS OF LOW CLOUDS NEAR THE IMMEDIATE LA AND VTU CO COAST...THE
LACK OF A HEALTHY INVERSION HAS KEPT MOST OF THE AREA SOUTH OF POINT
CONCEPTION CLEAR. THIS ALL HAS HELPED COOL THINGS OFF THIS
MORNING...WITH A SLIGHT CHILL TO THE AIR. TO THE NORTH...THE
NORTHERLY FLOW HAS HELPED STRATUS MOVE DOWN THE COAST FROM MONTEREY
AND COVER A LARGE PORTION OF INTERIOR SLO CO AND THE CENTRAL COAST.
WITH THE WEAK INVERSION...THINGS SHOULD CLEAR OUT FAIRLY QUICKLY.
ALTHOUGH THE CLOUD COVERAGE AND WEAK NORTHERLY FLOW HAS HELPED KEEP
MORNING MONS UP...THE COOLER AIR ALOFT WILL KEEP TEMPS THE SAME OR
COOLER FROM YESTERDAY ACROSS THE ENTIRE REGION. FORECAST TEMPS
REFLECT THIS CHANGE AND LOOK GOOD. WIND-WISE...BREEZY CONDITIONS
EXPECTED THIS AFTERNOON OVER THE CENTRAL COAST...LA MTNS...AND THE
ANTELOPE VALLEY. ALTHOUGH A FEW VERY LOCALIZED SPOTS MAY CLIP
ADVISORY THRESHOLDS...THE MAJORITY OF THESE AREAS WILL REMAIN BELOW.
...FROM PREVIOUS DISCUSSION...
THE UPPER LOW OVER NRN CA WILL OPEN UP AND LIFT NEWD TODAY...BUT A
BROAD UPPER TROUGH WILL LINGER ACROSS THE AREA THROUGH MONDAY
WITH WKLY CYCLONIC FLOW ALF. AT THE SFC DECENT LOW LVL N-S GRADS
SHOULD CAUSE SOME GUSTY WINDS ACROSS THE CENTRAL COAST AGAIN
THIS AFTERNOON...AND WITH GOOD W-E GRADS...STRONG WESTERLY WINDS
SHOULD AFFECT THE ANTELOPE VALLEY. THERE WILL BE ANOTHER ROUND
OF GUSTY WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY
TONIGHT. IT LOOKS AS THOUGH NWLY FLOW WILL BECOME MORE WDSPRD ACROSS
THE MTNS OF L.A./VTU COUNTIES TONIGHT...SO EXPECT LOCALLY STRONG
WINDS NEAR THE INTERSTATE 5 CORRIDOR TONIGHT/SUN MORNING. IT LOOKS
AS THOUGH WINDS WILL REMAIN BELOW ADVISORY LEVELS IN MOST AREAS.
UPSLOPE NLY FLOW SHOULD BRING SOME LOW CLOUDS TO THE NRN SLOPES OF
THE L.A/VTU COUNTY MTNS TONIGHT/SUN MORNING. THE WRF SHOWS A
STRONGER EDDY CRCLN TONIGHT/SUN MORNING...WITH MORE IN THE WAY OF
LOW CLDS/FOG IN CSTL SXNS OF L.A. AND PROBABLY VTU COUNTIES. CLOUDS
SHOULD AGAIN BE FAIRLY WDSPRD ON THE CENTRAL COAST AND IN THE SANTA
YNEZ/SALINAS VALLEYS. WITH THE EDDY CRCLN...SOME CLOUDS MAY PUSH
INTO THE SAN GABRIEL AND POSSIBLY SAN FERNANDO VALLEYS LATE TONIGHT
INTO SUN MORNING. WITH LITTLE CHANGE IN HGTS/THICKNESSES ACROSS THE
AREA ON SUN...EXPECT LITTLE CHANGE IN MAX TEMPS IN THE MTNS AND
DESERTS. ADDITIONAL SLIGHT COOLING AT 950 MB SHOULD BRING SLIGHT
COOLING TO COASTAL AND VALLEY AREAS ON SUNDAY.
THE WRF SHOWS SOMEWHAT WEAKER N-S GRADS AND NWLY LOW LVL FLOW SUN
NIGHT/MON...SO EXPECT LESS IN THE WAY OF WINDS IN THE MTNS AND
ACROSS THE SANTA YNEZ RANGE AND THE SBA COUNTY S CST. THERE MAY BE
SLIGHTLY DEEPER INLAND PENETRATION OF THE STRATUS SUN NIGHT/MON.
WITH HEIGHTS/THICKNESSES BEGINNING TO EDGE UPWARD ON MON...THERE MAY
BE A FEW DEGREES OF WARMING IN THE MTNS AND DESERTS...BUT WITH 950
MB TEMPS CHANGING LITTLE...EXPECT LITTLE CHANGE IN BELOW NORMAL MAX
TEMPS W OF THE MTNS FOR MON.
.LONG TERM...HEIGHTS WILL RISE ACROSS THE AREA TUE AS A FLAT RIDGE
BUILDS ALONG THE W CST. AT THE SAME TIME...LOW LVL ONSHORE GRADS
WILL WEAKEN. EXPECT THE MARINE LAYER TO BECOME MORE SHALLOW MON
NIGHT/TUE...WITH CLOUDS PROBABLY CONFINED TO THE CSTL PLAIN. MAX
TEMPS SHOULD BE UP A FEW DEGREES IN MOST AREAS ON TUE...MOST
NOTICEABLY IN THE VLYS. MODELS ARE A BIT DIFFERENT WITH THE UPPER
PATTERN LATER IN THE WEEK...SPECIFICALLY WITH THE PLACEMENT OF THE
UPPER HIGH WHICH IS NOW FCST TO BE SE OF THE FCST AREA AS OPPOSED TO
RIGHT OVER THE AREA. HEIGHTS ARE STILL RATHER HIGH...AND MODELS
STILL SHOW WEAK OFFSHORE TO NEUTRAL LOW LVL FLOW...AT LEAST WED AND
THU MORNINGS. THEREFORE...STILL EXPECT SIGNIFICANT WARMING ON WED...
ESPECIALLY IN THE VALLEYS...WHERE TEMPS SHOULD RISE WELL INTO THE
90S IN WARMER LOCATIONS...THEN IT WILL CONT TO BE RATHER WARM THU
AND FRI. MARINE LAYER SHOULD BE RATHER MINIMAL IN COVERAGE WED THRU
MORNING...CONFINED MAINLY TO AREAS WITHIN A FEW MILES OF THE CST.
&&
.AVIATION...20/1146Z.
IFR TO MVFR CONDITIONS ARE SHOWING SOME SIGNS OF SCATTERING OUT AT
TERMINALS NORTH OF POINT CONCEPTION. OCCASIONAL MVFR CEILINGS WILL
CONTINUE TO OCCUR AT TERMINALS NORTH OF POINT CONCEPTION. IFR
CONDITIONS WILL LIKELY REDEVELOP TONIGHT AROUND THE SAME TIME TO
LATER THAN LAST NIGHT AT TERMINALS NORTH OF POINT CONCEPTION...WHILE
MVFR CONDITIONS WILL LIKELY DEVELOP AFTER 08Z AT LOS ANGELES COUNTY
COASTAL TERMINALS. THERE IS A CHANCE OF MVFR CONDITIONS PUSHING INTO
KOXR...KBUR...AND KVNY AFTER 11Z TONIGHT.
KLAX...VFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST 08Z
TONIGHT...WITH A 20 PERCENT CHANCE OF MVFR CEILINGS PUSHING INTO THE
KLAX AREA BETWEEN 12Z AND 15Z. AFTER 08Z TONIGHT...THERE IS A 80
PERCENT CHANCE THAT MVFR CONDITIONS WILL DEVELOP...BUT MVFR
CONDITIONS COULD NOT ARRIVE UNTIL 11Z.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD...EXCEPT
FOR A 30 PERCENT CHANCE OF MVFR CONDITIONS AFTER 11Z TONIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BRUNO
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 201520
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
820 AM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 8:20 AM PDT SATURDAY...THE WEAK FRONT THAT
PRODUCED LIGHT RAIN IN THE NORTH BAY ON FRIDAY SPREAD SIGNIFICANT
LOW LEVEL MOISTURE ACROSS THE REGION OVERNIGHT. THAT MOISTURE AND
SOME LIFT COMBINED TO PRODUCE WIDESPREAD DRIZZLE NEAR THE COAST
OVERNIGHT...ENOUGH TO MEASURE IN SOME SPOTS PARTICULARLY NEAR
MONTEREY BAY. LOW CLOUDS CURRENTLY BLANKET MOST OF OUR CWA AND LOW
LEVEL MIXING IS POOR THIS MORNING. HOWEVER...THE CLOUD LAYER APPEARS
TO BE RELATIVELY THIN AND SHOULD CLEAR IN MOST INLAND AREAS BY LATE
MORNING. SOME PATCHES OF LOW CLOUDS WILL LIKELY LINGER NEAR THE
OCEAN WELL INTO THE AFTERNOON HOURS. TEMPERATURES WILL REMAIN COOLER
THAN NORMAL INLAND. COASTAL AREAS WILL HAVE COOLER TEMPS COMPARED
TO FRIDAY...BUT COULD STILL WARM TO NEAR NORMAL DEPENDING ON THE
AMOUNT OF AFTERNOON SUN.
THE LOW LEVELS WILL GRADUALLY DRY OVER THE NEXT 36 HOURS AS THE
FLOW VEERS MORE TO THE NORTH. BUT AREAS OF LOW CLOUDS WILL CONTINUE
THROUGH AT LEAST MIDDAY SUNDAY. BETTER LOW LEVEL MIXING WILL KICK IN
LATE SUNDAY INTO MONDAY AFTER A SHORTWAVE TROUGH PASSES INLAND TO
OUR NORTH. THIS MIXING WILL DRY OUT THE LOW LEVELS AND PRODUCE
MOSTLY SUNNY SKIES IN ALL AREAS EARLY NEXT WEEK. PLENTY OF SUN...
COMBINED WITH A WARMING AIRMASS UNDER A FLAT UPPER RIDGE...WILL
RESULT IN A GOOD WARM-UP ON MONDAY. TEMPERATURES SHOULD WARM BACK TO
NORMAL THAT DAY AND THEN REMAIN AT OR SLIGHTLY ABOVE NORMAL THROUGH
MUCH OF NEXT WEEK. SUCH A SCENARIO WILL VERIFY IF THE 06Z GFS IS
CORRECT. HOWEVER...COMPARED TO THE GFS THE 00Z ECMWF FORECASTS A
MORE ROBUST TROUGH MOVING THROUGH THE PAC NW AROUND MIDWEEK...WHICH
WOULD HALT ANY WARMING TREND AND PERHAPS LEAD TO SLIGHT MID
WEEK COOLING. WILL WAIT FOR THE 12Z MODEL RUNS BEFORE MAKING ANY
ADJUSTMENTS TO TEMPS NEXT WEEK.
&&
.AVIATION...AS OF 4:55 AM PDT SATURDAY...LOW CLOUD DECK HAS STARTED
TO LIFT WITH MOST LOCATIONS SEEING CIGS ABOVE 2000 FEET. SOME AREAS
SAW SOME BRIEF LIGHT RAIN OR HEAVY DRIZZLE LATE LAST NIGHT AND EARLY
THIS MORNING. WILL NOT RULE OUT SOME MORE DRIZZLE...MAINLY ALONG
THE COAST...SO PUT IN TEMPO ONLY FOR KMRY TERMINAL FOR A FEW HOURS
THIS MORNING. CIGS WILL CONTINUE TO LIFT THROUGHOUT THE DAY WITH
BASES ABOVE 4000 FEET AFTER 12 NOON. MOST AREAS SHOULD SCATTER OUT
AS WELL LATER IN THE AFTERNOON. HOWEVER...EXPECT THE MARINE LAYER
TO REFORM AND MVFR CIGS TO DEVELOP DURING THE EVENING...AND THE
STRATUS TO MAKE A WEAK PUSH INLAND. MODEL FORECAST ONSHORE GRADIENTS
APPEAR TO BE WEAK AND THE MARINE LAYER IS EXPECTED TO BE
APPROXIMATELY 1300 TO 1700 FEET DEEP.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
THIS AFTERNOON
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: TENTINGER
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 201156
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
456 AM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 3:20 AM PDT SATURDAY...ABUNDANT LOW LEVEL
MOISTURE ADVECTED INTO OUR DISTRICT BY THE UPPER LEVEL LOW THAT MOVED
THROUGH YESTERDAY. SOME LOCAL DRIZZLE HAS BEEN REPORTED MAINLY ALONG
THE COAST. VERY WEAK GRADIENTS WILL ALLOW THESE CLOUDS TO LINGER
THROUGH MOST OF THE MORNING. THE CLOUDS WILL BURN OFF LATE THIS
MORNING OR EARLY AFTERNOON AS DAYTIME HEATING OCCURS BUT TEMPERATURES
WILL BE COOL AGAIN TODAY. LOW CLOUDS EXPECTED TO RETURN TONIGHT AND
SUNDAY MORNING BUT SHOULD BURN OFF FASTER ON SUNDAY AS A WEAK
NORTHERLY FLOW DEVELOPS AT THE SURFACE. THIS DRY NORTHERLY FLOW WILL
KEEP MOST OF THE STRATUS OUT OF THE AREA FROM SUNDAY THROUGH ABOUT
TUESDAY. TEMPERATURES WILL WARM UP SIGNIFICANTLY SUNDAY THROUGH
TUESDAY. AN UPPER LEVEL DISTURBANCE WILL PASS TO THE NORTH LATE
WEDNESDAY BRINGING SOME COOLING NEAR THE COAST BY THURSDAY WITH
POSSIBLY A RETURN OF COASTAL STRATUS. LONG RANGE MODELS IN AGREEMENT
THAT BY LATE NEXT WEEK A WEAK UPPER LEVEL CUTOFF FORMS OFF SOUTHERN
CALIFORNIA BRINGING A WARM SOUTHWESTERLY FLOW TO THE DISTRICT. THIS
SHOULD WARM UP TEMPERATURES NEAR THE COAST ONCE AGAIN WHILE
INLAND AREAS WILL STAY WARM.
&&
.AVIATION...AS OF 4:55 AM PDT SATURDAY...LOW CLOUD DECK HAS STARTED
TO LIFT WITH MOST LOCATIONS SEEING CIGS ABOVE 2000 FEET. SOME AREAS
SAW SOME BRIEF LIGHT RAIN OR HEAVY DRIZZLE LATE LAST NIGHT AND EARLY
THIS MORNING. WILL NOT RULE OUT SOME MORE DRIZZLE...MAINLY ALONG
THE COAST...SO PUT IN TEMPO ONLY FOR KMRY TERMINAL FOR A FEW HOURS
THIS MORNING. CIGS WILL CONTINUE TO LIFT THROUGHOUT THE DAY WITH
BASES ABOVE 4000 FEET AFTER 12 NOON. MOST AREAS SHOULD SCATTER OUT
AS WELL LATER IN THE AFTERNOON. HOWEVER...EXPECT THE MARINE LAYER
TO REFORM AND MVFR CIGS TO DEVELOP DURING THE EVENING...AND THE
STRATUS TO MAKE A WEAK PUSH INLAND. MODEL FORECAST ONSHORE GRADIENTS
APPEAR TO BE WEAK AND THE MARINE LAYER IS EXPECTED TO BE
APPROXIMATELY 1300 TO 1700 FEET DEEP.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...POINT PINOS TO POINT PIEDRAS BLANCAS 0-20 NM
THIS AFTERNOON
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: TENTINGER
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 201148
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...DRIER AIR WILL MOVE INTO THE REGION THROUGH THE WEEKEND
...AS AN AREA OF LOW PRESSURE SETTLES ACROSS THE PACIFIC NORTHWEST.
DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY CLEAR SKIES
AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
TODAY...HIGH PRESSURE RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO
FLATTEN/WEAKEN IN RESPONSE TO A TROUGH OF LOW PRESSURE MOVING
ONSHORE NRN CA EARLY THIS MORNING. BEST DYNAMICS AND FORCING
ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL TO OUR NORTH...WHILE A
DRY WEST/SOUTHWESTERLY FLOW CONTINUES OVER OUR AREA. 24 HOUR CHANGE
PRODUCT INDICATES DEW POINTS OUT WEST HAVE DROPPED ABOUT 10 DEG
FROM THIS TIME YESTERDAY...AND THE DRIER CONDITIONS SHOULD LEAD TO
SLIGHTLY COOLER MORNING LOWS TODAY COMPARED TO FRIDAY.
FOR THE REMAINDER OF THE WEEKEND...DRIER AIR WILL CONTINUE TO SPREAD
WEST TO EAST ACROSS SOUTHEAST CA...SOUTHWEST AND SOUTH-CENTRAL
AZ...WITH LITTLE TO NO THREAT FOR SHOWERS/TSTMS. MEANWHILE...WE`LL
SEE LITTLE DAY TO DAY CHANGE IN TEMPS...WITH HIGHS AND LOWS
CONTINUING TO RUN A FEW DEG ABOVE NORMAL FOR MID/LATE SEPTEMBER.
MONDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
NO AVIATION CONCERNS FOR THE NEXT FEW DAYS. IN THE PHOENIX METRO
AREA...WINDS WILL REMAIN LIGHT AND EXHIBIT TYPICAL
UP-VALLEY/DOWN-VALLEY PATTERNS. FURTHER WEST NEAR
KYUM/KBLH/KIPL...WINDS WILL GENERALLY BE OUT OF THE SOUTH BEFORE
ACQUIRING MORE OF A WESTERLY COMPONENT AFTER 00Z SUN AS A TROUGH
MOVES INTO SOUTHERN CA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MOSTLY CLEAR SKIES WITH DRY CONDITIONS ARE EXPECTED THROUGH THE
EXTENDED. WINDS WILL INCREASE SUNDAY EVENING AND AGAIN
MONDAY...AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH THE PAC NW.
RH VALUES ARE EXPECTED TO DIP BELOW CRITICAL LEVELS ACROSS THE
SOUTHEAST CALIFORNIA DESERTS BY SUNDAY AFTERNOON...BUT SHOULD REMAIN
ABOVE CRITICAL LEVELS ELSEWHERE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...HIRSCH
FIRE WEATHER...WANEK
000
FXUS66 KLOX 201146 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
446 AM PDT SAT SEP 20 2008
UPDATED AVIATION SECTION
.SHORT TERM...LOW CLOUDS HAVE SPREAD INTO THE CENTRAL COAST AND
ACROSS THE SALINAS VALLEY IN SLO COUNTY EARLY THIS MORNING.
OTHERWISE...SKIES WERE CLEAR ACROSS THE AREA...ALTHOUGH STRATUS
MOVING RAPIDLY SEWD ACROSS THE COASTAL WATERS WAS BEGINNING TO CURL
TOWARD THE L.A. COUNTY COAST AS AN EDDY CRCLN TRIES TO DEVELOP.
BLV THAT AT LEAST PATCHY LOW CLOUDS/FOG WILL AFFECT THE L.A. COUNTY
CST BY DAYBREAK. WITH TEMPS AT 850/950 MB DOWN 2 TO 3 DEGREES C
ACROSS THE AREA...WOULD EXPECT MAX TEMPS TO BE DOWN A FEW DEGREES
FROM FRI...BELOW NORMAL ACROSS THE AREA FOR THIS TIME OF YEAR.
LOCALLY GUSTY NW TO NLY WINDS CONTD ACROSS SRN SBA COUNTY THIS
MORNING...BUT WINDS WERE BELOW ADVISORY LEVELS AND SHOULD DIMINISH
THIS MORNING.
THE UPPER LOW OVER NRN CA WILL OPEN UP AND LIFT NEWD TODAY...BUT A
BROAD UPPER TROUGH WILL LINGER ACROSS THE AREA THROUGH MONDAY
WITH WKLY CYCLONIC FLOW ALF. AT THE SFC DECENT LOW LVL N-S GRADS
SHOULD CAUSE SOME GUSTY WINDS ACROSS THE CENTRAL COAST AGAIN
THIS AFTERNOON...AND WITH GOOD W-E GRADS...STRONG WESTERLY WINDS
SHOULD AFFECT THE ANTELOPE VALLEY. THERE WILL BE ANOTHER ROUND
OF GUSTY WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY
TONIGHT. IT LOOKS AS THOUGH NWLY FLOW WILL BECOME MORE WDSPRD ACROSS
THE MTNS OF L.A./VTU COUNTIES TONIGHT...SO EXPECT LOCALLY STRONG
WINDS NEAR THE INTERSTATE 5 CORRIDOR TONIGHT/SUN MORNING. IT LOOKS
AS THOUGH WINDS WILL REMAIN BELOW ADVISORY LEVELS IN MOST AREAS.
UPSLOPE NLY FLOW SHOULD BRING SOME LOW CLOUDS TO THE NRN SLOPES OF
THE L.A/VTU COUNTY MTNS TONIGHT/SUN MORNING. THE WRF SHOWS A
STRONGER EDDY CRCLN TONIGHT/SUN MORNING...WITH MORE IN THE WAY OF
LOW CLDS/FOG IN CSTL SXNS OF L.A. AND PROBABLY VTU COUNTIES. CLOUDS
SHOULD AGAIN BE FAIRLY WDSPRD ON THE CENTRAL COAST AND IN THE SANTA
YNEZ/SALINAS VALLEYS. WITH THE EDDY CRCLN...SOME CLOUDS MAY PUSH
INTO THE SAN GABRIEL AND POSSIBLY SAN FERNANDO VALLEYS LATE TONIGHT
INTO SUN MORNING. WITH LITTLE CHANGE IN HGTS/THICKNESSES ACROSS THE
AREA ON SUN...EXPECT LITTLE CHANGE IN MAX TEMPS IN THE MTNS AND
DESERTS. ADDITIONAL SLIGHT COOLING AT 950 MB SHOULD BRING SLIGHT
COOLING TO COASTAL AND VALLEY AREAS ON SUNDAY.
THE WRF SHOWS SOMEWHAT WEAKER N-S GRADS AND NWLY LOW LVL FLOW SUN
NIGHT/MON...SO EXPECT LESS IN THE WAY OF WINDS IN THE MTNS AND
ACROSS THE SANTA YNEZ RANGE AND THE SBA COUNTY S CST. THERE MAY BE
SLIGHTLY DEEPER INLAND PENETRATION OF THE STRATUS SUN NIGHT/MON.
WITH HEIGHTS/THICKNESSES BEGINNING TO EDGE UPWARD ON MON...THERE MAY
BE A FEW DEGREES OF WARMING IN THE MTNS AND DESERTS...BUT WITH 950
MB TEMPS CHANGING LITTLE...EXPECT LITTLE CHANGE IN BELOW NORMAL MAX
TEMPS W OF THE MTNS FOR MON.
.LONG TERM...HEIGHTS WILL RISE ACROSS THE AREA TUE AS A FLAT RIDGE
BUILDS ALONG THE W CST. AT THE SAME TIME...LOW LVL ONSHORE GRADS
WILL WEAKEN. EXPECT THE MARINE LAYER TO BECOME MORE SHALLOW MON
NIGHT/TUE...WITH CLOUDS PROBABLY CONFINED TO THE CSTL PLAIN. MAX
TEMPS SHOULD BE UP A FEW DEGREES IN MOST AREAS ON TUE...MOST
NOTICEABLY IN THE VLYS. MODELS ARE A BIT DIFFERENT WITH THE UPPER
PATTERN LATER IN THE WEEK...SPECIFICALLY WITH THE PLACEMENT OF THE
UPPER HIGH WHICH IS NOW FCST TO BE SE OF THE FCST AREA AS OPPOSED TO
RIGHT OVER THE AREA. HEIGHTS ARE STILL RATHER HIGH...AND MODELS
STILL SHOW WEAK OFFSHORE TO NEUTRAL LOW LVL FLOW...AT LEAST WED AND
THU MORNINGS. THEREFORE...STILL EXPECT SIGNIFICANT WARMING ON WED...
ESPECIALLY IN THE VALLEYS...WHERE TEMPS SHOULD RISE WELL INTO THE
90S IN WARMER LOCATIONS...THEN IT WILL CONT TO BE RATHER WARM THU
AND FRI. MARINE LAYER SHOULD BE RATHER MINIMAL IN COVERAGE WED THRU
MORNING...CONFINED MAINLY TO AREAS WITHIN A FEW MILES OF THE CST.
&&
.AVIATION...20/1146Z.
IFR TO MVFR CONDITIONS ARE SHOWING SOME SIGNS OF SCATTERING OUT AT
TERMINALS NORTH OF POINT CONCEPTION. OCCASIONAL MVFR CEILINGS WILL
CONTINUE TO OCCUR AT TERMINALS NORTH OF POINT CONCEPTION. IFR
CONDITIONS WILL LIKELY REDEVELOP TONIGHT AROUND THE SAME TIME TO
LATER THAN LAST NIGHT AT TERMINALS NORTH OF POINT CONCEPTION...WHILE
MVFR CONDITIONS WILL LIKELY DEVELOP AFTER 08Z AT LOS ANGELES COUNTY
COASTAL TERMINALS. THERE IS A CHANCE OF MVFR CONDITIONS PUSHING INTO
KOXR...KBUR...AND KVNY AFTER 11Z TONIGHT.
KLAX...VFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST 08Z
TONIGHT...WITH A 20 PERCENT CHANCE OF MVFR CEILINGS PUSHING INTO THE
KLAX AREA BETWEEN 12Z AND 15Z. AFTER 08Z TONIGHT...THERE IS A 80
PERCENT CHANCE THAT MVFR CONDITIONS WILL DEVELOP...BUT MVFR
CONDITIONS COULD NOT ARRIVE UNTIL 11Z.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD...EXCEPT
FOR A 30 PERCENT CHANCE OF MVFR CONDITIONS AFTER 11Z TONIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BRUNO
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KEKA 201121
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
421 AM PDT SAT SEP 20 2008
.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD OVER NORTHERN CALIFORNIA
TODAY AND HOLD THROUGH MIDDAY SUNDAY BEFORE WEAKENING. LATE SUNDAY
NIGHT INCREASING CLOUDS AS A WEAK UPPER LEVEL TROUGH WILL MOVE
ACROSS THE REGION.
&&
.SHORT TERM...TODAY THROUGH MONDAY...THE GFS AND ECMWF MODELS ARE
IN GOOD AGREEMENT DURING THIS TIME PERIOD. OVERNIGHT...WIDESPREAD
SC CEILINGS AND AREAS OF VALLEY FOG WAS INDICATED BY SATELLITE
IMAGERY. AS THE TROUGH LIFTS TO THE NORTHEAST AND WEAK RIDGING
BUILDS OVER NORTHERN CALIFORNIA...THE CLOUDS WILL GRADUALLY BECOME
SCATTERED AND FOR INLAND LOCATIONS...THE SKIES WILL BECOME CLEAR.
THIS WILL MEAN A WARMING AND DRYING TREND FOR THE INTERIOR. THE
COAST WILL REMAIN UNDER THE INFLUENCE OF THE MARINE LAYER...AND
THE LOW CLOUDS AND PATCHY FOG WILL RETURN SATURDAY NIGHT INTO
SUNDAY MORNING. SUNDAY NIGHT A WEAK TROUGH WILL MOVE ACROSS THE
REGION. OTHER THAN AN INCREASE IN CLOUDS...NO WEATHER IS EXPECTED.
MONDAY A SLIGHTLY STRONGER RIDGE WILL BUILD AND MOVE ACROSS THE
REGION. KENNEDY
.LONG TERM...TUESDAY THROUGH FRIDAY...THE UPPER LEVEL RIDGE WILL
MOVE TO THE EAST AS AN UPPER LEVEL TROUGH APPROACHES THE PACIFIC
NORTHWEST. THE INLAND WARMING TREND WILL CONTINUE THROUGH TUESDAY.
THE MODELS DIFFER ON THE STRENGTH OF THIS TROUGH. THE ECMWF HAD A
DEEPER TROUGH AND EXTENDED THE PRECIPITATION FURTHER SOUTH THAN THE
GFS MODEL. AS A COMPROMISE...DID INCREASE THE POPS TO SLIGHT CHANCE
OF PRECIPITATION FOR WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT
NORTH OF KLAMATH. THE WEAK COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL BRING COOLER TEMPERATURES TO THE NORTHERN HALF OF THE CWA. THEN
FOR THURSDAY AND FRIDAY A WEAK RIDGE BUILD OVER THE REGION...BRINGING A
DRY PATTERN AND SEASON TEMPERATURES. THE ABSENCE OF A STRONG
OFFSHORE FLOW WILL CONTINUE THE USUAL REGIMEN OF LATE NIGHT AND
EARLY MORNING LOW CLOUDS ALONG THE COAST WITH PARTIAL CLEARING EACH
AFTERNOON. KENNEDY
&&
.AVIATION...CIGS EARLY THIS MORNING CONTINUE TO REMAIN
VFR...GENERALLY BETWEEN 030 AND 050 ACROSS THE REGION. THOUGH NO
SITES HAVE REPORTED ANY LOWERED VSBYS YET...WITH YESTERDAYS LIGHT
PRECIP ACROSS THE REGION...MOST AREAS CAN EXPECT SOME BRIEF PATCHY
MVFR FOG AROUND SUNRISE...ESPECIALLY IN VALLEY LOCATIONS AND ALONG
THE COAST.
LIGHT AND VARIABLE WINDS THIS MORNING WILL SHIFT TO THE N AND NW BY
THE AFTERNOON HOURS AS HIGH PRESSURE STRENGTHENS OVER THE EAST
PACIFIC. WITH FLOW REMAINING GENERALLY LIGHT THROUGH THIS
AFTERNOON...ITS LIKELY THAT SCT-BKN 030-050 CIGS WILL CONTINUE
THROUGH THE DAY ESPECIALLY OVER COASTAL HILLS. ALM
&&
.MARINE...W-NW SWELL TRAIN BEHIND THE UPPER LOW PASSAGE CONTINUES TO
AFFECT THE REGION WITH SEAS RUNNING BETWEEN 4 TO 6 FT THIS MORNING.
WAVE RIDER BUOYS CONTINUE TO SHOW A SOUTHERLY SWELL OF 2 TO 3 FT
MOVING THROUGH THE WATERS. SEAS WILL PEAK THIS MORNING AT THEIR
CURRENT HEIGHTS AND GRADUALLY SUBSIDE THROUGH THE REMAINDER OF THE
DAY BACK DOWN TO 2 TO 3 FT...WITH SEAS REMAINING MIXED AS SOUTHERLY
SWELL CONTINUES.
N-NW WINDS WILL INCREASE THROUGH THE DAY AS HIGH PRESSURE BUILDS
OVER THE EAST PACIFIC. WINDS ARE EXPECTED TO INCREASE TO SCA LEVELS
OVER THE OUTER WATERS LATER ON SUNDAY AS STRONGER HIGH PRESSURE
BUILDS INTO THE PAC NW BEHIND ANOTHER WEAK FRONT. MODELS HAVE BEEN
INCONSISTENT WITH STRENGTH OF WINDS IN THE MON-WED TIME FRAME...BUT
SFC PRESSURE PATTERN CONTINUES TO LOOKS GOOD FOR HIGH END SCA
CONDITIONS AND HAVE CONTINUED TO INDICATED GALE FORCE GUSTS FOR THE
OUTER WATERS. SCA CONDITIONS ARE EXPECTED TO CONTINUE OVER THE OUTER
COASTAL WATERS THROUGH THE MIDDLE OF NEXT WEEK. ALM
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KSTO 201114
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 AM PDT SAT SEP 20 2008
.DISCUSSION...
UPPER LOW EJECTING INTO THE GREAT BASIN EARLY THIS MORNING LEFT A
LOT OF LOW LEVEL MOISTURE IN ITS WAKE. AN AREA OF ALTOSTRATUS CLOUDS
CAN BE SEEN ON THE FOG ENHANCEMENT SATELLITE LOOP FROM AROUND
REDDING TO BEALE AFB. ALSO APPEARS AN AREA OF RADIATION STRATUS/FOG
HAS DEVELOPED EAST OF SACRAMENTO INTO THE MOTHERLODE AND NORTHERN
SAN JOAQUIN COUNTY. EXTENSIVE STRATUS HAS SPILLED INTO THE
DELTA...AND WE COULD SEE LOW CLOUDS CONTINUE TO DEVELOP OVER THE SOUTHERN
SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEYS THIS MORNING.
THE MODELS TREK THE TROF OVER ALASKA INTO CENTRAL CANADA BY THE
END OF THE WEEK...SETTING UP A PERIOD OF GENERALLY HIGHER 500MB
HEIGHTS AS THE DESERT SOUTHWEST RIDGE EXPANDS AND A DEEP LOW
DEVELOPS OVER THE NORTHEAST STATES. WITH LESS OF AN ONSHORE FLOW TODAY AND
MORE SUNSHINE...EXPECT A FEW DEGREES OF WARMING EVEN THOUGH THE AIR
MASS TEMPERATURE REMAINS SIMILAR TO YESTERDAY. MOUNTAIN AREAS MAY
HAVE SOME RESIDUAL COOLING FROM THE TROF/LOW. THE NEXT SHORT WAVE
MOVES QUICKLY THROUGH NORTHERN CALIFORNIA SUNDAY. IT WILL HAVE NO
PRECIPITATION AND MAY KICK UP SOME GUSTY WINDS. TEMPERATURES SUNDAY
WILL BE IN THE MID 80S AT SACRAMENTO AND IN THE 60S IN THE MOUNTAINS.
SURFACE HIGH PRESSURE BEHIND THIS FEATURE KICKS UP SOME DOWNVALLEY
WINDS SUNDAY NIGHT. THE 06Z GFS HAS CONSIDERABLY LESS UPPER LEVEL
FORCING WITH THIS EVENT THAN YESTERDAY`S RUNS. THE RIDGE BUILDS IN
MONDAY AND TUESDAY...THOUGH RECENT MODEL TRENDS HAVE NOT BEEN AS
STRONG WITH THIS. EXPECT FINE WEATHER INTO NEXT WEEK WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPERATURES AND NOT MUCH WIND.
LATER IN THE WEEK THE GFS DEVELOPS A TROF OFF THE WEST COAST...WHICH
IS ALSO A SHIFT FROM PREVIOUS SOLUTIONS. THE ECMWF AND CANADIAN
BRING TROFS INTO THE PACIFIC NORTHWEST EVERY FEW DAYS TOWARD THE END
OF THE WEEK. BY THE END OF THE WEEK THE CANADIAN HAS A DEEP POLAR
LOW NEAR ALASKA AND A STRONG JETSTREAM ALONG 50N. WHILE THERE ARE
SOME DIFFERENCES IN THE SPECIFICS...MOST MEDIUM RANGE MODELS ARE
TRENDING TOWARD THIS SOLUTION. THIS WOULD INDUCE EITHER A SPLIT FLOW
NEAR CALIFORNIA OR A PERSISTENT TROF OFF THE COAST AS THE PREVIOUSLY
ANTICIPATED HIGH AMPLITUDE RIDGE LIFTS WELL NORTH INTO WESTERN
CANADA. IF THIS DEVELOPS WE WILL HAVE TO KEEP A WATCHFUL EYE ON THE
RETURN OF TROPICAL SYSTEMS TO THE NORTHERN BAJA COAST. SG
&&
.AVIATION...
VFR CIGS AROUND 070-080 OVER THE INTERIOR WITH EXCEPTION TO AREAS OF
MVFR CIGS FORMING OVER THE ERN SIDE OF SRN SAC AND NRN SJ VALLEY.
AREA OF ST EXPANDING TO ABOUT 1500-1700 FT AGL INTO ERN
FOOTHILLS...SO TOPS APPEAR AROUND 015 TO 017. NOW ST WRN EDGE IS AT
KMHR MAKING SLOW SPREAD W. MAY BE TIL ABOUT 12Z OR 13Z THAT ST CIG
MAKES KSAC AND KSCK. KSMF TAF 60 PERCENT GOOD AS IS...MID CLOUD
OVER CENTRAL SAC VALLEY SPREADING SWD TOWARD KSMF COULD KEEP SIG ST
FROM FORMING. JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSTO 201113
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 AM PDT SAT SEP 20 2008
.DISCUSSION...
UPPER LOW EJECTING INTO THE GREAT BASIN EARLY THIS MORNING LEFT A
LOT OF LOW LEVEL MOISTURE IN ITS WAKE. AN AREA OF ALTOSTRATUS CLOUDS
CAN BE SEEN ON THE FOG ENHANCEMENT SATELLITE LOOP FROM AROUND
REDDING TO BEALE AFB. ALSO APPEARS AN AREA OF RADIATION STRATUS/FOG
HAS DEVELOPED EAST OF SACRAMENTO INTO THE MOTHERLODE AND NORTHERN
SAN JOAQUIN COUNTY. EXTENSIVE STRATUS HAS SPILLED INTO THE
DELTA...AND WE COULD SEE THIS MOISTURE CONTINUE TO SPILL INTO THE
SOUTHERN SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEY THIS MORNING.
THE MODELS TREK THE TROF OVER ALASKA INTO CENTRAL CANADA BY THE
END OF THE WEEK...SETTING UP A PERIOD OF GENERALLY HIGHER 500MB
HEIGHTS AS THE DESERT SOUTHWEST RIDGE EXPANDS AND A DEEP LOW
DEVELOPS OVER THE NORTHEAST STATES. WITH LESS OF AN ONSHORE FLOW TODAY AND
MORE SUNSHINE...EXPECT A FEW DEGREES OF WARMING EVEN THOUGH THE AIR
MASS TEMPERATURE REMAINS SIMILAR TO YESTERDAY. MOUNTAIN AREAS MAY
HAVE SOME RESIDUAL COOLING FROM THE TROF/LOW. THE NEXT SHORT WAVE
MOVES QUICKLY THROUGH NORTHERN CALIFORNIA SUNDAY. IT WILL HAVE NO
PRECIPITATION AND MAY KICK UP SOME GUSTY WINDS. TEMPERATURES SUNDAY
WILL BE IN THE MID 80S AT SACRAMENTO AND IN THE 60S IN THE MOUNTAINS.
SURFACE HIGH PRESSURE BEHIND THIS FEATURE KICKS UP SOME DOWNVALLEY
WINDS SUNDAY NIGHT. THE 06Z GFS HAS CONSIDERABLY LESS UPPER LEVEL
FORCING WITH THIS EVENT THAN YESTERDAY`S RUNS. THE RIDGE BUILDS IN
MONDAY AND TUESDAY...THOUGH RECENT MODEL TRENDS HAVE NOT BEEN AS
STRONG WITH THIS. EXPECT FINE WEATHER INTO NEXT WEEK WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPERATURES AND NOT MUCH WIND.
LATER IN THE WEEK THE GFS DEVELOPS A TROF OFF THE WEST COAST...WHICH
IS ALSO A SHIFT FROM PREVIOUS SOLUTIONS. THE ECMWF AND CANADIAN
BRING TROFS INTO THE PACIFIC NORTHWEST EVERY FEW DAYS TOWARD THE END
OF THE WEEK. BY THE END OF THE WEEK THE CANADIAN HAS A DEEP POLAR
LOW NEAR ALASKA AND A STRONG JETSTREAM ALONG 50N. WHILE THERE ARE
SOME DIFFERENCES IN THE SPECIFICS...MOST MEDIUM RANGE MODELS ARE
TRENDING TOWARD THIS SOLUTION. THIS WOULD INDUCE EITHER A SPLIT FLOW
NEAR CALIFORNIA OR A PERSISTENT TROF OFF THE COAST AS THE PREVIOUSLY
ANTICIPATED HIGH AMPLITUDE RIDGE LIFTS WELL NORTH INTO WESTERN
CANADA. IF THIS DEVELOPS WE WILL HAVE TO KEEP A WATCHFUL EYE ON THE
RETURN OF TROPICAL SYSTEMS TO THE NORTHERN BAJA COAST. SG
&&
.AVIATION...
VFR CIGS AROUND 070-080 OVER THE INTERIOR WITH EXCEPTION TO AREAS OF
MVFR CIGS FORMING OVER THE ERN SIDE OF SRN SAC AND NRN SJ VALLEY.
AREA OF ST EXPANDING TO ABOUT 1500-1700 FT AGL INTO ERN
FOOTHILLS...SO TOPS APPEAR AROUND 015 TO 017. NOW ST WRN EDGE IS AT
KMHR MAKING SLOW SPREAD W. MAY BE TIL ABOUT 12Z OR 13Z THAT ST CIG
MAKES KSAC AND KSCK. KSMF TAF 60 PERCENT GOOD AS IS...MID CLOUD
OVER CENTRAL SAC VALLEY SPREADING SWD TOWARD KSMF COULD KEEP SIG ST
FROM FORMING. JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KLOX 201111
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
334 AM PDT SAT SEP 20 2008
.SHORT TERM...LOW CLOUDS HAVE SPREAD INTO THE CENTRAL COAST AND
ACROSS THE SALINAS VALLEY IN SLO COUNTY EARLY THIS MORNING.
OTHERWISE...SKIES WERE CLEAR ACROSS THE AREA...ALTHOUGH STRATUS
MOVING RAPIDLY SEWD ACROSS THE COASTAL WATERS WAS BEGINNING TO CURL
TOWARD THE L.A. COUNTY COAST AS AN EDDY CRCLN TRIES TO DEVELOP.
BLV THAT AT LEAST PATCHY LOW CLOUDS/FOG WILL AFFECT THE L.A. COUNTY
CST BY DAYBREAK. WITH TEMPS AT 850/950 MB DOWN 2 TO 3 DEGREES C
ACROSS THE AREA...WOULD EXPECT MAX TEMPS TO BE DOWN A FEW DEGREES
FROM FRI...BELOW NORMAL ACROSS THE AREA FOR THIS TIME OF YEAR.
LOCALLY GUSTY NW TO NLY WINDS CONTD ACROSS SRN SBA COUNTY THIS
MORNING...BUT WINDS WERE BELOW ADVISORY LEVELS AND SHOULD DIMINISH
THIS MORNING.
THE UPPER LOW OVER NRN CA WILL OPEN UP AND LIFT NEWD TODAY...BUT A
BROAD UPPER TROUGH WILL LINGER ACROSS THE AREA THROUGH MONDAY
WITH WKLY CYCLONIC FLOW ALF. AT THE SFC DECENT LOW LVL N-S GRADS
SHOULD CAUSE SOME GUSTY WINDS ACROSS THE CENTRAL COAST AGAIN
THIS AFTERNOON...AND WITH GOOD W-E GRADS...STRONG WESTERLY WINDS
SHOULD AFFECT THE ANTELOPE VALLEY. THERE WILL BE ANOTHER ROUND
OF GUSTY WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY
TONIGHT. IT LOOKS AS THOUGH NWLY FLOW WILL BECOME MORE WDSPRD ACROSS
THE MTNS OF L.A./VTU COUNTIES TONIGHT...SO EXPECT LOCALLY STRONG
WINDS NEAR THE INTERSTATE 5 CORRIDOR TONIGHT/SUN MORNING. IT LOOKS
AS THOUGH WINDS WILL REMAIN BELOW ADVISORY LEVELS IN MOST AREAS.
UPSLOPE NLY FLOW SHOULD BRING SOME LOW CLOUDS TO THE NRN SLOPES OF
THE L.A/VTU COUNTY MTNS TONIGHT/SUN MORNING. THE WRF SHOWS A
STRONGER EDDY CRCLN TONIGHT/SUN MORNING...WITH MORE IN THE WAY OF
LOW CLDS/FOG IN CSTL SXNS OF L.A. AND PROBABLY VTU COUNTIES. CLOUDS
SHOULD AGAIN BE FAIRLY WDSPRD ON THE CENTRAL COAST AND IN THE SANTA
YNEZ/SALINAS VALLEYS. WITH THE EDDY CRCLN...SOME CLOUDS MAY PUSH
INTO THE SAN GABRIEL AND POSSIBLY SAN FERNANDO VALLEYS LATE TONIGHT
INTO SUN MORNING. WITH LITTLE CHANGE IN HGTS/THICKNESSES ACROSS THE
AREA ON SUN...EXPECT LITTLE CHANGE IN MAX TEMPS IN THE MTNS AND
DESERTS. ADDITIONAL SLIGHT COOLING AT 950 MB SHOULD BRING SLIGHT
COOLING TO COASTAL AND VALLEY AREAS ON SUNDAY.
THE WRF SHOWS SOMEWHAT WEAKER N-S GRADS AND NWLY LOW LVL FLOW SUN
NIGHT/MON...SO EXPECT LESS IN THE WAY OF WINDS IN THE MTNS AND
ACROSS THE SANTA YNEZ RANGE AND THE SBA COUNTY S CST. THERE MAY BE
SLIGHTLY DEEPER INLAND PENETRATION OF THE STRATUS SUN NIGHT/MON.
WITH HEIGHTS/THICKNESSES BEGINNING TO EDGE UPWARD ON MON...THERE MAY
BE A FEW DEGREES OF WARMING IN THE MTNS AND DESERTS...BUT WITH 950
MB TEMPS CHANGING LITTLE...EXPECT LITTLE CHANGE IN BELOW NORMAL MAX
TEMPS W OF THE MTNS FOR MON.
.LONG TERM...HEIGHTS WILL RISE ACROSS THE AREA TUE AS A FLAT RIDGE
BUILDS ALONG THE W CST. AT THE SAME TIME...LOW LVL ONSHORE GRADS
WILL WEAKEN. EXPECT THE MARINE LAYER TO BECOME MORE SHALLOW MON
NIGHT/TUE...WITH CLOUDS PROBABLY CONFINED TO THE CSTL PLAIN. MAX
TEMPS SHOULD BE UP A FEW DEGREES IN MOST AREAS ON TUE...MOST
NOTICEABLY IN THE VLYS. MODELS ARE A BIT DIFFERENT WITH THE UPPER
PATTERN LATER IN THE WEEK...SPECIFICALLY WITH THE PLACEMENT OF THE
UPPER HIGH WHICH IS NOW FCST TO BE SE OF THE FCST AREA AS OPPOSED TO
RIGHT OVER THE AREA. HEIGHTS ARE STILL RATHER HIGH...AND MODELS
STILL SHOW WEAK OFFSHORE TO NEUTRAL LOW LVL FLOW...AT LEAST WED AND
THU MORNINGS. THEREFORE...STILL EXPECT SIGNIFICANT WARMING ON WED...
ESPECIALLY IN THE VALLEYS...WHERE TEMPS SHOULD RISE WELL INTO THE
90S IN WARMER LOCATIONS...THEN IT WILL CONT TO BE RATHER WARM THU
AND FRI. MARINE LAYER SHOULD BE RATHER MINIMAL IN COVERAGE WED THRU
MORNING...CONFINED MAINLY TO AREAS WITHIN A FEW MILES OF THE CST.
&&
.AVIATION...20/1115Z. WILL BE UPDATED SHORTLY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BRUNO
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 201033
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
330 AM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 3:20 AM PDT SATURDAY...ABUNDANT LOW LEVEL
MOISTURE ADVECTED INTO OUR DISTRICT BY THE UPPER LEVEL LOW THAT MOVED
THROUGH YESTERDAY. SOME LOCAL DRIZZLE HAS BEEN REPORTED MAINLY ALONG
THE COAST. VERY WEAK GRADIENTS WILL ALLOW THESE CLOUDS TO LINGER
THROUGH MOST OF THE MORNING. THE CLOUDS WILL BURN OFF LATE THIS
MORNING OR EARLY AFTERNOON AS DAYTIME HEATING OCCURS BUT TEMPERATURES
WILL BE COOL AGAIN TODAY. LOW CLOUDS EXPECTED TO RETURN TONIGHT AND
SUNDAY MORNING BUT SHOULD BURN OFF FASTER ON SUNDAY AS A WEAK
NORTHERLY FLOW DEVELOPS AT THE SURFACE. THIS DRY NORTHERLY FLOW WILL
KEEP MOST OF THE STRATUS OUT OF THE AREA FROM SUNDAY THROUGH ABOUT
TUESDAY. TEMPERATURES WILL WARM UP SIGNIFICANTLY SUNDAY THROUGH
TUESDAY. AN UPPER LEVEL DISTURBANCE WILL PASS TO THE NORTH LATE
WEDNESDAY BRINGING SOME COOLING NEAR THE COAST BY THURSDAY WITH
POSSIBLY A RETURN OF COASTAL STRATUS. LONG RANGE MODELS IN AGREEMENT
THAT BY LATE NEXT WEEK A WEAK UPPER LEVEL CUTOFF FORMS OFF SOUTHERN
CALIFORNIA BRINGING A WARM SOUTHWESTERLY FLOW TO THE DISTRICT. THIS
SHOULD WARM UP TEMPERATURES NEAR THE COAST ONCE AGAIN WHILE
INLAND AREAS WILL STAY WARM.
&&
.AVIATION...AS OF 10:30 PM FRIDAY...CEILINGS HAVE LOWERED A BIT
FASTER THAN EXPECTED WITH IFR REPORTED AT SEVERAL LOCATIONS IN THE
LAST FEW HOURS. HIGHER HUMIDITIES AND NOCTURNAL COOLING HAVE LED TO
MORE IFR CEILINGS BEING REPORTED. CLOUDS WILL VERY LIKELY STAY IN FOR
THE NIGHT. A DRIER W-NW FLOW AND WARMING SATURDAY WILL LIKELY HELP
MIX OUT THE CLOUDS BY MID TO LATE MORNING. WINDS WILL BE LIGHT TO
LOCALLY MODERATE ONSHORE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.NONE
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSTO 201019
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 AM PDT SAT SEP 20 2008
.DISCUSSION...
UPPER LOW EJECTING INTO THE GREAT BASIN EARLY THIS MORNING LEFT A
LOT OF LOW LEVEL MOISTURE IN ITS WAKE. AN AREA OF ALTOSTRATUS CLOUDS
CAN BE SEEN ON THE FOG ENHANCEMENT SATELLITE LOOP FROM AROUND
REDDING TO BEALE AFB. ALSO APPEARS AN AREA OF RADIATION STRATUS/FOG
HAS DEVELOPED EAST OF SACRAMENTO INTO THE MOTHERLODE AND NORTHERN
SAN JOAQUIN COUNTY. EXTENSIVE STRATUS HAS SPILLED INTO THE
DELTA...BUT THIS IS NOT EXPECTED TO ADVECT INLAND AS THE WINDS ARE
FAIRLY LIGHT AT KSFO THIS MORNING.
THE MODELS TREK THE TROF OVER ALASKA INTO CENTRAL CANADA BY THE
END OF THE WEEK...SETTING UP A PERIOD OF GENERALLY HIGHER 500MB
HEIGHTS AS THE DESERT SOUTHWEST RIDGE EXPANDS AND A DEEP LOW
DEVELOPS OVER THE NORTHEAST STATES. WITH LESS OF AN ONSHORE FLOW TODAY AND
MORE SUNSHINE...EXPECT A FEW DEGREES OF WARMING EVEN THOUGH THE AIR
MASS TEMPERATURE REMAINS SIMILAR TO YESTERDAY. MOUNTAIN AREAS MAY
HAVE SOME RESIDUAL COOLING FROM THE TROF/LOW. THE NEXT SHORT WAVE
MOVES QUICKLY THROUGH NORTHERN CALIFORNIA SUNDAY. IT WILL HAVE NO
PRECIPITATION AND MAY KICK UP SOME GUSTY WINDS. TEMPERATURES SUNDAY
WILL BE IN THE MID 80S AT SACRAMENTO AND IN THE 60S IN THE MOUNTAINS.
SURFACE HIGH PRESSURE BEHIND THIS FEATURE KICKS UP SOME DOWNVALLEY
WINDS SUNDAY NIGHT. THE 06Z GFS HAS CONSIDERABLY LESS UPPER LEVEL
FORCING WITH THIS EVENT THAN YESTERDAY`S RUNS. THE RIDGE BUILDS IN
MONDAY AND TUESDAY...THOUGH RECENT MODEL TRENDS HAVE NOT BEEN AS
STRONG WITH THIS. EXPECT FINE WEATHER INTO NEXT WEEK WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPERATURES AND NOT MUCH WIND.
LATER IN THE WEEK THE GFS DEVELOPS A TROF OFF THE WEST COAST...WHICH
IS ALSO A SHIFT FROM PREVIOUS SOLUTIONS. THE ECMWF AND CANADIAN
BRING TROFS INTO THE PACIFIC NORTHWEST EVERY FEW DAYS TOWARD THE END
OF THE WEEK. BY THE END OF THE WEEK THE CANADIAN HAS A DEEP POLAR
LOW NEAR ALASKA AND A STRONG JETSTREAM ALONG 50N. WHILE THERE ARE
SOME DIFFERENCES IN THE SPECIFICS...MOST MEDIUM RANGE MODELS ARE
TRENDING TOWARD THIS SOLUTION. THIS WOULD INDUCE EITHER A SPLIT FLOW
NEAR CALIFORNIA OR A PERSISTENT TROF OFF THE COAST AS THE PREVIOUSLY
ANTICIPATED HIGH AMPLITUDE RIDGE LIFTS WELL NORTH INTO WESTERN
CANADA. IF THIS DEVELOPS WE WILL HAVE TO KEEP A WATCHFUL EYE ON THE
RETURN OF TROPICAL SYSTEMS TO THE NORTHERN BAJA COAST. SG
&&
.AVIATION...
VFR CIGS AROUND 070-080 OVER THE INTERIOR WITH EXCEPTION TO AREAS OF
MVFR CIGS FORMING OVER THE ERN SIDE OF SRN SAC AND NRN SJ VALLEY.
AREA OF ST EXPANDING TO ABOUT 1500-1700 FT AGL INTO ERN
FOOTHILLS...SO TOPS APPEAR AROUND 015 TO 017. NOW ST WRN EDGE IS AT
KMHR MAKING SLOW SPREAD W. MAY BE TIL ABOUT 12Z OR 13Z THAT ST CIG
MAKES KSAC AND KSCK. KSMF TAF 60 PERCENT GOOD AS IS...MID CLOUD
OVER CENTRAL SAC VALLEY SPREADING SWD TOWARD KSMF COULD KEEP SIG ST
FROM FORMING. JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KMTR 201012
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
315 AM PDT SAT SEP 20 2008
.DISCUSSION...AS OF 3:00 AM PDT SATURDAY...ABUNDANT LOW LEVEL
MOISTURE ADVECTED INTO OUR DISTRICT BY THE UPPER LEVEL LOW THAT MOVED
THROUGH YESTERDAY. SOME LOCAL DRIZZLE HAS BEEN REPORTED MAINLY ALONG
THE COAST. VERY WEAK GRADIENTS WILL ALLOW THESE CLOUDS TO LINGER
THROUGH MOST OF THE MORNING. THE CLOUDS WILL BURN OFF LATE THIS
MORNING OR EARLY AFTERNOON AS DAYTIME HEATING OCCURS BUT TEMPERATURES
WILL BE COOL AGAIN TODAY. LOW CLOUDS EXPECTED TO RETURN TONIGHT AND
SUNDAY MORNING BUT SHOULD BURN OFF FASTER ON SUNDAY AS A WEAK
NORTHERLY FLOW DEVELOPS AT THE SURFACE. THIS DRY NORTHERLY FLOW WILL
KEEP MOST OF THE STRATUS OUT OF THE AREA FROM SUNDAY THROUGH ABOUT
TUESDAY. TEMPERATURES WILL WARM UP SIGNIFICANTLY SUNDAY THROUGH
TUESDAY. AN UPPER LEVEL DISTURBANCE WILL PASS TO THE NORTH ON
WEDNESDAY BRINGING SOME COOLING WITH POSSIBLY A RETURN OF COASTAL
STRATUS.
LONG RANGE MODELS IN AGREEMENT THAT BY LATE NEXT WEEK A WEAK
UPPER LEVEL CUTOFF FORMS OFF SOUTHERN CALIFORNIA BRINGING A
SOUTHWESTERLY FLOW TO THE DISTRICT WITH WARMER TEMPERATURES.
&&
.AVIATION...AS OF 10:30 PM FRIDAY...CEILINGS HAVE LOWERED A BIT
FASTER THAN EXPECTED WITH IFR REPORTED AT SEVERAL LOCATIONS IN THE
LAST FEW HOURS. HIGHER HUMIDITIES AND NOCTURNAL COOLING HAVE LED TO
MORE IFR CEILINGS BEING REPORTED. CLOUDS WILL VERY LIKELY STAY IN FOR
THE NIGHT. A DRIER W-NW FLOW AND WARMING SATURDAY WILL LIKELY HELP
MIX OUT THE CLOUDS BY MID TO LATE MORNING. WINDS WILL BE LIGHT TO
LOCALLY MODERATE ONSHORE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.NONE
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 200953
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
251 AM MST SAT SEP 20 2008
SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION
.SYNOPSIS...DRIER AIR WILL MOVE INTO THE REGION THROUGH THE WEEKEND
...AS AN AREA OF LOW PRESSURE SETTLES ACROSS THE PACIFIC NORTHWEST.
DRY CONDITIONS WILL CONTINUE NEXT WEEK...UNDER MOSTLY CLEAR SKIES
AND SLIGHTLY WARMER THAN AVERAGE TEMPERATURES.
&&
.DISCUSSION...
TODAY...HIGH PRESSURE RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO
FLATTEN/WEAKEN IN RESPONSE TO A TROUGH OF LOW PRESSURE MOVING
ONSHORE NRN CA EARLY THIS MORNING. BEST DYNAMICS AND FORCING
ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL TO OUR NORTH...WHILE A
DRY WEST/SOUTHWESTERLY FLOW CONTINUES OVER OUR AREA. 24 HOUR CHANGE
PRODUCT INDICATES DEW POINTS OUT WEST HAVE DROPPED ABOUT 10 DEG
FROM THIS TIME YESTERDAY...AND THE DRIER CONDITIONS SHOULD LEAD TO
SLIGHTLY COOLER MORNING LOWS TODAY COMPARED TO FRIDAY.
FOR THE REMAINDER OF THE WEEKEND...DRIER AIR WILL CONTINUE TO SPREAD
WEST TO EAST ACROSS SOUTHEAST CA...SOUTHWEST AND SOUTH-CENTRAL
AZ...WITH LITTLE TO NO THREAT FOR SHOWERS/TSTMS. MEANWHILE...WE`LL
SEE LITTLE DAY TO DAY CHANGE IN TEMPS...WITH HIGHS AND LOWS
CONTINUING TO RUN A FEW DEG ABOVE NORMAL FOR MID/LATE SEPTEMBER.
MONDAY THROUGH THE END OF THE WORK WEEK...MODELS REMAIN IN GOOD
AGREEMENT THAT A LARGE ANTI-CYCLONE WILL CONTINUE OVER MUCH OF THE
SOUTHWEST...WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LITTLE
DAY TO DAY CHANGE IN TEMPERATURES.
&&
.AVIATION...
SOUTHEAST CA...AND SOUTHWEST AND SOUTH CENTRAL AZ...INCLUDING KPHX...
KIWA...KNYL...KIPL...AND KBLH. MOSTLY CLEAR SKIES AND LIGHT WIND
CAN BE EXPECTED THROUGH AT LEAST 03Z SUN.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MOSTLY CLEAR SKIES WITH DRY CONDITIONS ARE EXPECTED THROUGH THE
EXTENDED. WINDS WILL INCREASE SUNDAY EVENING AND AGAIN
MONDAY...AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH THE PAC NW.
RH VALUES ARE EXPECTED TO DIP BELOW CRITICAL LEVELS ACROSS THE
SOUTHEAST CALIFORNIA DESERTS BY SUNDAY AFTERNOON...BUT SHOULD REMAIN
ABOVE CRITICAL LEVELS ELSEWHERE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...VASQUEZ
FIRE WEATHER...WANEK
000
FXUS65 KREV 200934
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
230 AM PDT SAT SEP 20 2008
.SHORT TERM...
UPPER LOW OVER NERN CA-NW NV WILL LIFT NORTHEAST INTO OR/ID TODAY.
ISOLD SHOWERS AND AN OCCASIONAL TSTM AHEAD OF THIS LOW ARE STILL
ONGOING OVER PERSHING COUNTY/FAR NRN WASHOE COUNTY...BUT THESE
SHOULD MOVE NORTH OF THE AREA NEAR SUNRISE. DRIER WEST TO NORTHWEST
FLOW WILL DOMINATE THE AREA OVER THE WEEKEND...ALTHOUGH WEAK SHORT
WAVES WILL MOVE ACROSS THE AREA TODAY AND SUNDAY BRINGING PERIODS OF
CLOUDS ACROSS THE AREA. TEMPERATURES WILL REMAIN JUST BELOW
NORMAL...WITH HIGHS IN THE UPPER 70S TO LOW 80S IN WRN NV AND IN THE
LOW 70S IN THE SIERRA.
A STRONGER SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW MOVES ACROSS
THE CWA SUNDAY NIGHT INTO MONDAY MORNING. SOME MOISTURE IS
ASSOCIATED WITH THE SHORT WAVE...BUT IT LOOKS TO ONLY GENERATE
CLOUDS ACROSS THE NRN HALF OF THE AREA. MOST MID LEVEL MOISTURE AND
INSTABILITY REMAINS JUST NORTH OF THE NV-OR BORDER. THEREFORE THE
FORECAST WILL REMAIN DRY FOR NOW...BUT CANNOT RULE OUT A FEW SHOWERS
NEAR THE OREGON BORDER. THE SHORT WAVE WILL ALSO BRING IN SLIGHTLY
COOLER WEATHER WITH TEMPERATURES LOWERING A COUPLE DEGREES BY
MONDAY. OTHERWISE DRY CONDITIONS ARE EXPECTED ON MONDAY. GMCGUIRE
.LONG TERM...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE WILL BRING DRY CONDITIONS WITH ABOVE NORMAL
TEMPERATURES TO THE EASTERN SIERRA AND WESTERN NV DURING THE PERIOD.
STORM ENERGY REMAINS WELL NORTH OF NV ALTHOUGH SHORTWAVES MOVING BY
DRAG SOME HIGH LEVEL MOISTURE AND BRING LOCAL GUSTY WINDS TO THE
NORTHERN ZONES ON WEDNESDAY. A WEAK TROUGH DEVELOPS OVER THE EASTERN
PACIFIC ON FRIDAY AND TURNS THE FLOW A LITTLE MORE SOUTHERLY. THE
ECMWF SHOWS 500MB MOISTURE OVER MONO AND MINERAL COUNTIES FRIDAY
AFTERNOON WHILE THE GFS IS DRIER AND STABLE ALTHOUGH PRECIPITABLE
WATER VALUES CLIMB ABOVE A HALF INCH. WILL CONTINUE THE ON-GOING
FORECAST OF SUNNY AND DRY...WITH SOME INCREASED CLOUD COVER AND LOW
POPS. RC
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH 12Z SUNDAY. ISOLD -SHRA NORTHEAST OF
KLOL WILL DISSIPATE OR MOVE WELL AWAY FROM THE AREA BY 15Z. RC
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSGX 200915
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
220 AM PDT SAT SEP 20 2008
.SYNOPSIS...
THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS...EXTENDING LOCALLY
INLAND. UPPER LEVEL LOW PRESSURE MOVING PAST TO THE NORTH WILL BRING
COOLER WEATHER INTO EARLY NEXT WEEK. LOCALLY WINDY IN THE MOUNTAINS
AND DESERTS AT TIMES. WARMER DURING THE SECOND HALF OF NEXT WEEK
UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH MONDAY)...
A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH THE PACIFIC NORTHWEST
WILL BRING SLOW COOLING THROUGH THE WEEKEND AND SLOW DEEPENING OF
THE MARINE LAYER INTO MONDAY. THE MARINE LAYER HAS DEEPENED TO
AROUND 1500 FEET AND CONTINUES TO DEEPEN. CURRENT SATELLITE IMAGERY
SHOWS PATCHY STRATUS ALONG THE SAN DIEGO COUNTY COAST WITH A LARGER
AREA ALONG THE CENTRAL COAST EXTENDING SOUTHWARD OVER THE OUTER
COASTAL WATERS. THIS AREA IS EXPECTED TO OVERSPREAD THE COASTAL
WATERS THROUGH SUNRISE AND SPREAD LOCALLY INLAND.
&&
.LONG TERM (TUESDAY THROUGH FRIDAY)...
HIGH PRESSURE BUILDING OVER THE SOUTHWEST STATES WILL BRING WARMING
TO ABOVE SEASONAL AVERAGES AND A SHALLOWER MARINE LAYER.
&&
.AVIATION...
200900Z...MARINE LAYER INCREASING RAPIDLY WITH TOP CURRENTLY AROUND
1800 FT. BASES AROUND 1500 FT MSL. VSBY MOSTLY ABOVE 7SM WITH AREAS
3-5SM AND LOCAL BELOW 3SM IN THE FOOTHILLS. SMALL PATCH OF STRATUS
CURRENTLY NEAR FAR SOUTHERN SAN DIEGO COUNTY COAST. EXPECT AREAS OF
STRATUS MOVING INTO THE SAN DIEGO COUNTY INLAND VALLEYS AND SOME
GETTING INTO ORANGE COUNTY. STRATUS WILL DISSIPATE BY AROUND 18Z.
STRATUS SHOULD MOVE IN LATE AFTERNOON AND COVER THE COAST TO SAN
DIEGO INLAND VALLEYS AND ORANGE COUNTY WITH SOME INTO THE WEST PART
OF THE INLAND EMPIRE TONIGHT. EXPECT STRATUS TO CLEAR EARLIER
SUNDAY. OTHERWISE CLEAR.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...WHITLOW
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KHNX 200905
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
205 AM PDT SAT SEP 20 2008
.DISCUSSION...
UPPER LOW THAT BROUGHT THE FALL LIKE TEMPERATURES TO THE REGION IS
SLOWLY CROSSING NRN CA ATTM AND IS EXPECTED TO CONTINUE ON ITS
EASTWARD TRACK INTO THE NRN ROCKIES IN 24 HOURS. ZONAL FLOW WILL
SET UP WITH ONLY SLIGHT MODERATION IN THE TEMPERATURES EXPECTED
THROUGH THE WEEKEND. SOME HIGH CLOUDS ARE POSSIBLE FROM TIME TO
TIME TODAY BUT NOT ENOUGH TO WARRANT PARTLY CLOUDY IN THE ZONES
AND GRIDS. IT MAY NEED UPDATING TODAY IF MODELS UNDER FORECAST THE
MOISTURE ACROSS THE REGION.
AN UPPER RIDGE IS EXPECTED TO BUILD IN FROM THE SOUTHWEST AND
PROMOTE WARMER TEMPERATURES BEGINNING EARLY NEXT WEEK. THE WARMING
TREND WILL CONTINUE THROUGH MOST OF NEXT WEEK AS THE RIDGE WILL
BUILD NORTH ACROSS CA. THE STORM TRACK LIFTS WELL NORTH OF THE
AREA IN INTO THE PAC NW....SO IT WILL REMAIN DRY THROUGH THE
PERIOD.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CA INTERIOR
THROUGH 12Z SUNDAY.
&&
.AIR QUALITY ISSUES...
ON SATURDAY SEPTEMBER 20 2008...UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO...KERN AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JDB
AVN/FW...DCH
WEATHER.GOV/HANFORD
000
FXUS66 KSTO 200833
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
130 AM PDT SAT SEP 20 2008
UPDATED AVIATION DISCUSSION FOR STRATUS AGAIN
.DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DIED OUT THIS EVENING OVER CALIFORNIA
DUE TO THE DISTURBANCE LIFTING NORTHEAST. ALL REMAINING SHOWER AND
THUNDERSTORM ACTIVITY HAS NOW MOVED INTO NORTHERN NEVADA...WESTERN
OREGON AND SOUTHERN IDAHO. 850 MB TEMPERATURES DO NOT CHANGE THAT
MUCH FOR SATURDAY SO EXPECT TEMPERATURES NEAR TODAYS HIGHS IN THE
CENTRAL VALLEY.
OVERNIGHT MODELS ARE INDICATING A MOIST LAYER OVER THE SOUTHERN
SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEY THAT MAY END UP FORMING A
LOW STRATUS DECK OVER PORTIONS OF THAT AREA. THE REMAINING AREAS
WILL CONTINUE TO SEE DECREASING CLOUDS IF THEY HAVE NOT DISSIPATED
ALREADY.
SEVERAL SHORTWAVES WILL MOVE THROUGH THE PACIFIC NORTHWEST THROUGH
THE MIDDLE OF NEXT WEEK WHICH WILL HELP TO KEEP THE REGIONS
TEMPERATURES COMFORTABLE. WHILE SOME WARMING MAY OCCUR MONDAY
THROUGH THURSDAY OF NEXT WEEK THE AMOUNT APPEARS A LITTLE LESS
PRONOUNCED AND THE OFFSHORE FLOW MUCH WEAKER THAN A DAY AGO. THE
STRONGEST OFFSHORE FLOW APPEARS TO OCCUR ON SUNDAY NIGHT AND
MONDAY AND ANOTHER SHORTWAVE IS NOW PROGGED TO MOVE INTO THE PACIFIC
NORTHWEST NEXT FRIDAY TO FLATTEN OUT THE RIDGE THAT DEVELOPS OVER
NORTHERN CALIFORNIA.
&&
.UPDATE AVIATION...
VFR CIGS AROUND 080 OVER THE INTERIOR WITH EXCEPTION TO AREAS OF
MVFR CIGS FORMING OVER THE SRN SAC AND NRN SJ VALLEY. AREA OF ST
EXPANDING TO ABOUT 1500-1700 FT AGL INTO ERN FOOTHILLS...NOW
BEGINNING TO STRETCH N...W AND SW. SO TOPS APPEAR AROUND 015 TO
017. BUMPED UP IMPACT TIME OF ST AT KSAC...KMHR AND KSCK. MAY TAKE
LONGER FOR ST TO SPREAD W TO KSMF...BUT STILL MAY NEED TO BUMP UP
CIG TIMING BETWEEN 11-12Z. HOWEVER...MID CLOUD OVER CENTRAL SAC
VALLEY SPREADING SWD TOWARD KSMF COULD KEEP SIG ST FROM FORMING.
JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSTO 200829
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
130 AM PDT SAT SEP 20 2008
UPDATED AVIATION DISCUSSION FOR STRATUS AGAIN
.DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DIED OUT THIS EVENING OVER CALIFORNIA
DUE TO THE DISTURBANCE LIFTING NORTHEAST. ALL REMAINING SHOWER AND
THUNDERSTORM ACTIVITY HAS NOW MOVED INTO NORTHERN NEVADA...WESTERN
OREGON AND SOUTHERN IDAHO. 850 MB TEMPERATURES DO NOT CHANGE THAT
MUCH FOR SATURDAY SO EXPECT TEMPERATURES NEAR TODAYS HIGHS IN THE
CENTRAL VALLEY.
OVERNIGHT MODELS ARE INDICATING A MOIST LAYER OVER THE SOUTHERN
SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEY THAT MAY END UP FORMING A
LOW STRATUS DECK OVER PORTIONS OF THAT AREA. THE REMAINING AREAS
WILL CONTINUE TO SEE DECREASING CLOUDS IF THEY HAVE NOT DISSIPATED
ALREADY.
SEVERAL SHORTWAVES WILL MOVE THROUGH THE PACIFIC NORTHWEST THROUGH
THE MIDDLE OF NEXT WEEK WHICH WILL HELP TO KEEP THE REGIONS
TEMPERATURES COMFORTABLE. WHILE SOME WARMING MAY OCCUR MONDAY
THROUGH THURSDAY OF NEXT WEEK THE AMOUNT APPEARS A LITTLE LESS
PRONOUNCED AND THE OFFSHORE FLOW MUCH WEAKER THAN A DAY AGO. THE
STRONGEST OFFSHORE FLOW APPEARS TO OCCUR ON SUNDAY NIGHT AND
MONDAY AND ANOTHER SHORTWAVE IS NOW PROGGED TO MOVE INTO THE PACIFIC
NORTHWEST NEXT FRIDAY TO FLATTEN OUT THE RIDGE THAT DEVELOPS OVER
NORTHERN CALIFORNIA.
&&
.UPDATE AVIATION...
VFR CIGS AROUND 080 OVER THE INTERIOR WITH EXCEPTION TO AREAS OF
MVFR CIGS FORMING OVER THE SRN SAC AND NRN SJ VALLEY. AREA OF ST
EXPANDING TO ABOUT 1200-1500 FT AGL INTO ERN FOOTHILLS...NOW
BEGINNING TO STRETCH N...W AND SW. SO TOPS APPEAR AROUND 015.
BUMPED UP IMPACT TIME OF ST AT KSAC...KMHR AND KSCK. MAY TAKE
LONGER FOR ST TO SPREAD W TO KSMF...BUT STILL MAY NEED TO BUMP UP
CIG TIMING BETWEEN 11-12Z. HOWEVER...MID CLOUD OVER CENTRAL SAC
VALLEY SPREADING SWD TOWARD KSMF COULD KEEP SIG ST FROM FORMING.
JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSTO 200646
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1145 PM PDT FRI SEP 19 2008
UPDATED AVIATION DISCUSSION FOR STRATUS
.DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DIED OUT THIS EVENING OVER CALIFORNIA
DUE TO THE DISTURBANCE LIFTING NORTHEAST. ALL REMAINING SHOWER AND
THUNDERSTORM ACTIVITY HAS NOW MOVED INTO NORTHERN NEVADA...WESTERN
OREGON AND SOUTHERN IDAHO. 850 MB TEMPERATURES DO NOT CHANGE THAT
MUCH FOR SATURDAY SO EXPECT TEMPERATURES NEAR TODAYS HIGHS IN THE
CENTRAL VALLEY.
OVERNIGHT MODELS ARE INDICATING A MOIST LAYER OVER THE SOUTHERN
SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEY THAT MAY END UP FORMING A
LOW STRATUS DECK OVER PORTIONS OF THAT AREA. THE REMAINING AREAS
WILL CONTINUE TO SEE DECREASING CLOUDS IF THEY HAVE NOT DISSIPATED
ALREADY.
SEVERAL SHORTWAVES WILL MOVE THROUGH THE PACIFIC NORTHWEST THROUGH
THE MIDDLE OF NEXT WEEK WHICH WILL HELP TO KEEP THE REGIONS
TEMPERATURES COMFORTABLE. WHILE SOME WARMING MAY OCCUR MONDAY
THROUGH THURSDAY OF NEXT WEEK THE AMOUNT APPEARS A LITTLE LESS
PRONOUNCED AND THE OFFSHORE FLOW MUCH WEAKER THAN A DAY AGO. THE
STRONGEST OFFSHORE FLOW APPEARS TO OCCUR ON SUNDAY NIGHT AND
MONDAY AND ANOTHER SHORTWAVE IS NOW PROGGED TO MOVE INTO THE PACIFIC
NORTHWEST NEXT FRIDAY TO FLATTEN OUT THE RIDGE THAT DEVELOPS OVER
NORTHERN CALIFORNIA.
&&
.UPDATE AVIATION...
VFR CONDITIONS OVER THE INTERIOR WITH EXCEPTION TO AREAS OF MVFR
CIGS FORMING OVER THE SOUTHERN SACRAMENTO AND NORTHERN SAN JOAQUIN
VALLEY. ALREADY SAW PATCH FORM ABOUT 5SM SOUTH OF KSAC AND KMHR AT
06Z. HIGHT RH COULD SEE MVFR STRATUS IN QUICKER THAN 10Z FOR
KSAC...KMHR AND KSCK. WILL KEEP TAFS AS IS AND CLOSELY WATCH THE
STRATUS. EXPECT MVFR TO LAST TIL AROUND 17Z. JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KLOX 200547 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 PM PDT FRI SEP 19 2008
.SHORT TERM (TODAY-MON)...
TEMPERATURES COOLED DOWN RATHER SIGNIFICANTLY ACROSS PORTIONS OF THE
SLO INTERIOR VALLEYS WHERE PASO ROBLES ONLY REACHED 76 DEGREES
TODAY. MOST OTHER INTERIOR LOCATIONS WERE DOWN BETWEEN 3-5 DEGREES
AS BOUNDARY LAYER TEMPS COOLED A BIT AND THICKNESS LVLS DROPPED IN
THE WAKE OF A WEAK FRONTAL BOUNDARY THAT MOVED INLAND OVERNIGHT.
MOST LA/VTU SBA COUNTY VALLEYS REMAINED IN THE 80S. WHILE LOW CLOUDS
WERE ABSENT OVERNIGHT AND THIS MORNING...DOWNTOWN WAS ABLE WARM UP
AS HIGH AS PALMDALE TO 86 DEGREES.
CURRENTLY...SKIES ARE MOSTLY CLEAR SOUTH OF POINT CONCEPTION...WHILE
A BAND OF CLOUDS ASSOCIATED WITH A WEAK TROF WITH CIGS OF NEAR 5000
FT IS BEGINNING TO SURGE INTO THE CENTRAL COAST THIS EVENING. HARD
TO TELL THE EXTENT OF CLOUD COVERAGE OVERNIGHT...BUT MODELS SUGGEST
THAT CLOUDS SHOULD MOVE INTO THE SALINAS RIVER VALLEY OVERNIGHT. NOT
ANTICIPATING ANY FOG DUE TO HIGH CLOUD BASES. LATEST AMDAR SOUNDING
NEAR KLAX INDICATED MARINE LAYER NEAR 800 FT...BUT WITH APPROACHING
WEAK TROF...MARINE LAYER SHOULD DEEPEN WHILE INVERSION WEAKENS
OVERNIGHT. NAM-WRF IS ADVERTISING EDDY CIRCULATION TO HELP SPIN UP
SOME STRATUS ACROSS LA/VTU COUNTY COASTAL AREAS OVERNIGHT. FEEL THAT
THERE WILL BE SOME PATCHY LOW CLOUDS ACROSS LA COUNTY AFTER
MIDNIGHT...AND POSSIBLY VTU COUNTIES. WITH INVERSION WEAKENING...LOW
CLOUDS COULD POP UP RANDOMLY ACROSS PORTIONS OF LA/VTU COUNTY
COASTAL AREAS...BUT SHOULD REMAIN PATCHY IN NATURE. KEPT SKIES CLEAR
FOR SBA SOUTH COAST OVERNIGHT...BUT WITH A FEW BANDS OF CLOUDS NEAR
POINT CONCEPTION...A MINI EDDY COULD DEVELOP BETWEEN SBA AND THE
CHANNEL ISLANDS LATER TONIGHT. HOWEVER...THERE IS A DECENT NORTHERLY
GRADIENT BETWEEN KSBA-KSMX WHICH SHOULD KEEP THE SANTA BARBARA SOUTH
COAST CLEAR.
SATURDAY LOOKS TO BE A FEW DEGREES COOLER...ALTHOUGH 950 MB TEMPS DO
NOT CHANGE MUCH...BUT ONSHORE FLOW INCREASES ACROSS THE REGION.
EXPECT MOST VALLEY LOCATIONS TO BE IN THE MID 80S. WHILE THE COASTAL
AREAS REMAIN FROM THE UPPER 60S AND 70S TO AROUND 80 INLAND AREAS.
A MORE IMPRESSIVE EDDY DEVELOPS ACROSS THE SO CAL BIGHT SAT NIGHT
AND SHOULD REACH THE COASTAL VALLEYS KEEPING TEMPS COOLER THAN AVG
ON SUNDAY. THERE CONTINUES TO BE A DECENT NORTHERLY GRADIENT
AFFECTING THE SANTA BARBARA COUNTY MTNS AND SBA SOUTH COAST WHICH
SHOULD BRING ADDITIONAL LOCAL GUSTY NORTHWEST TO NORTH WINDS ACROSS
THE USUAL WINDY PASSES AND CANYONS NEAR GAVIOTA TO MONTECITO. MODELS
ALSO PICK UP SOME LOCAL NORTHERLY WINDS 15 TO 30 MPH ACROSS THE I-5
CORRIDOR LATE SAT NIGHT INTO EARLY SUNDAY MORNING WITH A FEW CLOUDS
POSSIBLE PUSHED UP AGAINST THE NRN SLOPES OF THE VTU/WESTERN LA
COUNTY MTNS EARLY SUNDAY MORNING. THERE COULD BE A FEW DEGREES OF
WARMING ACROSS THE INTERIOR PORTIONS OF THE FORECAST AREA AS WEEK
UPPER RIDGE SLOWLY BUILDS IN FROM THE SOUTHWEST. HOWEVER A CATALINA
EDDY SHOULD PERSIST SUNDAY NIGHT INTO MONDAY CONTINUING TO LEAVE THE
COASTAL AREAS RELATIVELY COOL FOR MONDAY.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (TUE-FRI)...WARMING TREND STILL ON TRACK FOR THE MIDDLE
OF NEXT WEEK. GFS HAS BACKED OFF SLIGHTLY ON THE OFFSHORE FLOW FOR
WED AND THU BUT GRADIENTS SHOULD AT LEAST BE NEAR NEUTRAL IF NOT
SLIGHTLY OFFSHORE. STILL THINK THE GFS IS UNDERDOING THE WARMING AT
950 AS WELL THE MOS GUIDANCE HIGHS. GIVEN THE STRENGTH OF THE UPPER
HIGH AND NEAR NEUTRAL OR SLIGHTLY OFFSHORE SURFACE GRADIENTS, HIGHS
SHOULD BE CLOSE TO 100 IN THE VALLEYS AND CLOSE TO 90 ACROSS THE
INLAND COASTAL PLAIN. FOR THIS REASON CURRENT FORECAST CONTINUES TO
BE WARMER THAN MOS GUIDANCE. WARMING TREND SHOULD END FRI AS ANOTHER
TROF APPROACHES THE COAST AND HIGH PRESSURE MOVES EAST.
&&
.AVIATION...20/0545Z.
STRATUS WILL BE PATCHY IN NATURE S OF POINT CONCEPTION...CONFINED
MAINLY TO THE COASTAL PLAIN. N OF PT CONCEPTION...EXPECT WDSPRD IFR
CIGS THROUGH 17Z. THERE WILL BE SOME LL WIND SHEAR NEAR KSBA THROUGH
12Z.
KLAX...THERE IS A 70 PERCENT CHANCE OF LOW CLOUDS AND FOG WITH
IFR OR LOW MVFR CIGS AND MVFR VSBYS BETWEEN 11Z AND 17Z.
KBUR...HIGH CONFIDENCE IN CLEAR SKIES THROUGH SATURDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KAPLAN/WOFFORD
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KLOX 200544 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 PM PDT FRI SEP 19 2008
.SHORT TERM (TODAY-MON)...
TEMPERATURES COOLED DOWN RATHER SIGNIFICANTLY ACROSS PORTIONS OF THE
SLO INTERIOR VALLEYS WHERE PASO ROBLES ONLY REACHED 76 DEGREES
TODAY. MOST OTHER INTERIOR LOCATIONS WERE DOWN BETWEEN 3-5 DEGREES
AS BOUNDARY LAYER TEMPS COOLED A BIT AND THICKNESS LVLS DROPPED IN
THE WAKE OF A WEAK FRONTAL BOUNDARY THAT MOVED INLAND OVERNIGHT.
MOST LA/VTU SBA COUNTY VALLEYS REMAINED IN THE 80S. WHILE LOW CLOUDS
WERE ABSENT OVERNIGHT AND THIS MORNING...DOWNTOWN WAS ABLE WARM UP
AS HIGH AS PALMDALE TO 86 DEGREES.
CURRENTLY...SKIES ARE MOSTLY CLEAR SOUTH OF POINT CONCEPTION...WHILE
A BAND OF CLOUDS ASSOCIATED WITH A WEAK TROF WITH CIGS OF NEAR 5000
FT IS BEGINNING TO SURGE INTO THE CENTRAL COAST THIS EVENING. HARD
TO TELL THE EXTENT OF CLOUD COVERAGE OVERNIGHT...BUT MODELS SUGGEST
THAT CLOUDS SHOULD MOVE INTO THE SALINAS RIVER VALLEY OVERNIGHT. NOT
ANTICIPATING ANY FOG DUE TO HIGH CLOUD BASES. LATEST AMDAR SOUNDING
NEAR KLAX INDICATED MARINE LAYER NEAR 800 FT...BUT WITH APPROACHING
WEAK TROF...MARINE LAYER SHOULD DEEPEN WHILE INVERSION WEAKENS
OVERNIGHT. NAM-WRF IS ADVERTISING EDDY CIRCULATION TO HELP SPIN UP
SOME STRATUS ACROSS LA/VTU COUNTY COASTAL AREAS OVERNIGHT. FEEL THAT
THERE WILL BE SOME PATCHY LOW CLOUDS ACROSS LA COUNTY AFTER
MIDNIGHT...AND POSSIBLY VTU COUNTIES. WITH INVERSION WEAKENING...LOW
CLOUDS COULD POP UP RANDOMLY ACROSS PORTIONS OF LA/VTU COUNTY
COASTAL AREAS...BUT SHOULD REMAIN PATCHY IN NATURE. KEPT SKIES CLEAR
FOR SBA SOUTH COAST OVERNIGHT...BUT WITH A FEW BANDS OF CLOUDS NEAR
POINT CONCEPTION...A MINI EDDY COULD DEVELOP BETWEEN SBA AND THE
CHANNEL ISLANDS LATER TONIGHT. HOWEVER...THERE IS A DECENT NORTHERLY
GRADIENT BETWEEN KSBA-KSMX WHICH SHOULD KEEP THE SANTA BARBARA SOUTH
COAST CLEAR.
SATURDAY LOOKS TO BE A FEW DEGREES COOLER...ALTHOUGH 950 MB TEMPS DO
NOT CHANGE MUCH...BUT ONSHORE FLOW INCREASES ACROSS THE REGION.
EXPECT MOST VALLEY LOCATIONS TO BE IN THE MID 80S. WHILE THE COASTAL
AREAS REMAIN FROM THE UPPER 60S AND 70S TO AROUND 80 INLAND AREAS.
A MORE IMPRESSIVE EDDY DEVELOPS ACROSS THE SO CAL BIGHT SAT NIGHT
AND SHOULD REACH THE COASTAL VALLEYS KEEPING TEMPS COOLER THAN AVG
ON SUNDAY. THERE CONTINUES TO BE A DECENT NORTHERLY GRADIENT
AFFECTING THE SANTA BARBARA COUNTY MTNS AND SBA SOUTH COAST WHICH
SHOULD BRING ADDITIONAL LOCAL GUSTY NORTHWEST TO NORTH WINDS ACROSS
THE USUAL WINDY PASSES AND CANYONS NEAR GAVIOTA TO MONTECITO. MODELS
ALSO PICK UP SOME LOCAL NORTHERLY WINDS 15 TO 30 MPH ACROSS THE I-5
CORRIDOR LATE SAT NIGHT INTO EARLY SUNDAY MORNING WITH A FEW CLOUDS
POSSIBLE PUSHED UP AGAINST THE NRN SLOPES OF THE VTU/WESTERN LA
COUNTY MTNS EARLY SUNDAY MORNING. THERE COULD BE A FEW DEGREES OF
WARMING ACROSS THE INTERIOR PORTIONS OF THE FORECAST AREA AS WEEK
UPPER RIDGE SLOWLY BUILDS IN FROM THE SOUTHWEST. HOWEVER A CATALINA
EDDY SHOULD PERSIST SUNDAY NIGHT INTO MONDAY CONTINUING TO LEAVE THE
COASTAL AREAS RELATIVELY COOL FOR MONDAY.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (TUE-FRI)...WARMING TREND STILL ON TRACK FOR THE MIDDLE
OF NEXT WEEK. GFS HAS BACKED OFF SLIGHTLY ON THE OFFSHORE FLOW FOR
WED AND THU BUT GRADIENTS SHOULD AT LEAST BE NEAR NEUTRAL IF NOT
SLIGHTLY OFFSHORE. STILL THINK THE GFS IS UNDERDOING THE WARMING AT
950 AS WELL THE MOS GUIDANCE HIGHS. GIVEN THE STRENGTH OF THE UPPER
HIGH AND NEAR NEUTRAL OR SLIGHTLY OFFSHORE SURFACE GRADIENTS, HIGHS
SHOULD BE CLOSE TO 100 IN THE VALLEYS AND CLOSE TO 90 ACROSS THE
INLAND COASTAL PLAIN. FOR THIS REASON CURRENT FORECAST CONTINUES TO
BE WARMER THAN MOS GUIDANCE. WARMING TREND SHOULD END FRI AS ANOTHER
TROF APPROACHES THE COAST AND HIGH PRESSURE MOVES EAST.
&&
.AVIATION...20/0545Z.
KLAX...THERE IS A 70 PERCENT CHANCE OF LOW CLOUDS AND FOG WITH
IFR OR LOW MVFR CIGS AND MVFR VSBYS BETWEEN 11Z AND 17Z.
KBUR...HIGH CONFIDENCE IN CLEAR SKIES THROUGH SATURDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...KAPLAN/WOFFORD
AVIATION...SWEET
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 200530
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1030 PM PDT FRI SEP 19 2008
.DISCUSSION...AS OF 8:30 PM PDT FRIDAY...AN UPPER LEVEL LOW IS MOVING
INLAND OVER FAR NORTHERN CA THIS EVENING AND A WEAK SURFACE COLD
FRONT IS DISSIPATING OVER THE SF BAY AREA. LIGHT RAIN FELL ALONG THE
WEAK FRONT THIS AFTERNOON AND EARLY EVENING...MAINLY IN THE NORTH
BAY. AS MUCH AS 0.05 INCHES OF RAIN FELL ACROSS PORTIONS OF SONOMA
COUNTY THIS AFTERNOON AND A FEW SPRINKLES MADE IT AS FAR SOUTH AS THE
OAKLAND AREA EARLY THIS EVENING. RADAR...SATELLITE AND SURFACE OBS
ALL INDICATE THAT RAINFALL HAS MOSTLY ENDED. EXPECT NO MORE THAN
A FEW SPRINKLES IN THE N AND E BAY FOR THE REMAINDER OF THE EVENING.
THE DISSIPATING FRONT BROUGHT CONSIDERABLE LOW LEVEL MOISTURE INTO
OUR AREA. BECAUSE LOW LEVEL MIXING IS VERY WEAK BEHIND THE FRONT...
LOW CLOUDS WILL LIKELY REMAIN THROUGH THE NIGHT AND INTO SATURDAY
MORNING. A FORECAST UPDATE WAS COMPLETED EARLIER THIS EVENING TO ADD
MORE CLOUDS TO THE SF BAY AREA TONIGHT AND SATURDAY MORNING. SOLAR
HEATING SHOULD BE STRONG ENOUGH ON SATURDAY TO CLEAR MOST CLOUDS FROM
OUR FORECAST AREA BY MIDDAY...EXCEPT PERHAPS FOR A FEW SPOTS ALONG
THE COAST. INLAND TEMPERATURES WILL CONTINUE AT BELOW NORMAL LEVELS
ON SATURDAY. COASTAL AREAS...WHICH WERE NEAR NORMAL TODAY...SHOULD BE
COOLER ON SATURDAY DUE TO THE ANTICIPATED MORNING CLOUD COVER.
NOT MUCH CHANGE IS EXPECTED ON SUNDAY. SOME LOW CLOUDINESS WILL
LIKELY LINGER...BUT TEMPERATURES SHOULD START TO WARM IN MOST AREAS.
A GENERAL WARMING TREND IS FORECAST FROM MONDAY THROUGH THE MIDDLE OF
NEXT WEEK AS A FLAT UPPER RIDGE DEVELOPS ALONG THE WEST COAST...THE
AIRMASS WARMS TO SEASONABLE LEVELS...AND ONSHORE FLOW WEAKENS.
&&
.AVIATION...AS OF 10:30 PM FRIDAY...CEILINGS HAVE LOWERED A BIT
FASTER THAN EXPECTED WITH IFR REPORTED AT SEVERAL LOCATIONS IN THE
LAST FEW HOURS. HIGHER HUMIDITIES AND NOCTURNAL COOLING HAVE LED TO
MORE IFR CEILINGS BEING REPORTED. CLOUDS WILL VERY LIKELY STAY IN FOR
THE NIGHT. A DRIER W-NW FLOW AND WARMING SATURDAY WILL LIKELY HELP
MIX OUT THE CLOUDS BY MID TO LATE MORNING. WINDS WILL BE LIGHT TO
LOCALLY MODERATE ONSHORE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.NONE
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
| 
