000
FXUS66 KSGX 201646
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
845 AM PST TUE JAN 20 2009
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO WEDNESDAY FOR INLAND AREAS UNDER
WEAKENING HIGH PRESSURE WITH SLOW COOLING SPREADING INLAND FROM THE
COAST. FOR LATE WEDNESDAY NIGHT THROUGH THURSDAY...A TROUGH OF LOW
PRESSURE WILL BRING PRECIPITATION TO MOST AREAS FROM THE COAST TO
THE MOUNTAINS. DRY WEATHER WILL RETURN AGAIN FRIDAY AND SATURDAY
UNDER WEAK HIGH PRESSURE...WITH ANOTHER CHANCE FOR SHOWERS LATE
SATURDAY INTO SUNDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
ANOTHER RELATIVELY DRY AND WARM NIGHT UNDER OPAQUE HIGH CLOUDS AND
OFFSHORE FLOW. STRATUS/FOG FAILED TO APPEAR OVERNIGHT ALONG THE
COAST/OVER ADJACENT WATER AS DEWPOINTS NEVER MADE IT ABOVE LOW 50S
BEFORE DRIER FROM LAND BREEZE MOVED BACK ACROSS THESE AREAS.
NONETHELESS THE COOLING AND MOISTENING TREND IS UNDERWAY PER 24 HOUR
TRENDS IN TEMPS/DEWPOINTS...AS THE OFFSHORE PRESSURE GRADIENT
RELAXES AND 1000-500 MB THICKNESS VALUES FALL. THE HIGH PRESSURE
RIDGE AXIS HAS SHIFTED FAR ENOUGH NORTH AND EAST TO ALLOW SPLIT FLOW
TO DEVELOP IN THE VICINITY OF 35N 135W LONGITUDE. THE JET LEVEL
WINDS DEPICTED UPSTREAM FROM THIS POINT AND PROGGED TO COME INTO THE
SOUTHERN BRANCH ARE STRONG ENOUGH TO DEVELOP A NEGATIVE TILT TROUGH
ABOUT 450 MILES OFF THE COAST BY TONIGHT. THIS TROUGH IS ADVANCED
VERY SLOWLY TOWARDS THE SOUTHERN/CENTRAL CALIFORNIA COAST
WEDNESDAY/WEDNESDAY NIGHT. SOME MODELS HAVE HINTED AT THIS SLOWER
MOVEMENT AND THE 20/00Z AND 20/12Z RUNS SHOW ALL MODELS NOW IN
AGREEMENT...NOT MOVING THE TROUGH CLOSE ENOUGH TO SOUTHWEST
CALIFORNIA TO GENERATE ENOUGH LIFTING/COOLING TO SATURATE AIR MASS
AND BEGIN PRECIPITATION OVER COASTS/VALLEYS/MOUNTAINS UNTIL EARLY
THURSDAY MORNING. HAVE ALREADY UPDATED AND SENT GRIDS AS WELL AS
ISSUED FORECAST PRODUCT UPDATES TO REFLECT THIS. REMAINDER OF
FORECAST FOR THURSDAY AND BEYOND LOOKS GOOD. THE TROUGH AXIS MOVES
INLAND THURSDAY AFTERNOON...AND BY THURSDAY EVENING IS EAST OF
CALIFORNIA. NAM12 MODEL SHOWS PRECIPITATION STILL BEING GENERATED
WEST OF THE MOUNTAINS THURSDAY EVENING...THIS MAY BE COMING FROM
MOIST LOW LEVEL FLOW BEING LIFTED/CONVERGED...UPSLOPE/ISLAND
EFFECTS...HOWEVER FAIRLY STRONG RIDGING ALOFT IS INDICATED WITH
RESULTANT SUBSIDENCE COUNTERING THESE EFFECTS. CURRENT GRIDS HAVE
PRECIPITATION ENDING THURSDAY AFTERNOON AT 1600 PST/0000 UTC. STORM
QPF TOTALS HAVE BEEN ADJUSTED DOWNWARD SLIGHTLY DUE TO LATER
ONSET/SHORTER DURATION OF PRECIPITATION...NOW HAVE LESS THAN A
QUARTER INCH COASTS AND VALLEYS...A THIRD TO A HALF INCH COASTAL
SLOPES...AND TRACE TO LESS THAN A TENTH OF AN INCH DESERT
SLOPES/DESERT FLOORS. FREEZING LEVEL REMAINS FAIRLY HIGH...SNOW
LEVEL NOT EXPECTED TO LOWER BELOW 8000 FEET DURING PRECIPITATION
EVENT.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
FROM PREVIOUS DISCUSSION...ECMWF PREFERRED THROUGH THE EXTENDED.
WEAK SHORTWAVE RIDGING SHOULD BRING DRYING AND MINOR WARMING FOR
FRIDAY AND EARLY SATURDAY THOUGH STILL WITH A DECENT AMOUNT OF
CLOUDS. A TROUGH OF LOW PRESSURE IN NORTHWEST FLOW MAY BRING A
CHANCE OF PRECIPITATION LATE IN THE WEEKEND WITH COOLER MOIST
CYCLONIC FLOW CONTINUING INTO MONDAY.
&&
.AVIATION...
201500Z...VARIABLE BROKEN TO OVERCAST CLOUDS AT OR ABOVE FL150 TODAY
LOWERING TONIGHT AND WEDNESDAY TO AROUND FL100. VISIBILITIES SHOULD
REMAIN UNRESTRICTED THROUGH WEDNESDAY MORNING.
LOCAL GUSTY NORTHEAST WINDS BELOW PASSES AND CANYONS THIS MORNING
WILL DIMINISH THROUGH THE AFTERNOON. HORTON
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH RIP CURRENT RISK FOR ORANGE AND SAN DIEGO COUNTY COASTAL
AREAS
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 201134
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
335 AM PST TUE JAN 20 2009
.SYNOPSIS...
WARM DRY WEATHER WILL CONTINUE INTO WEDNESDAY FOR INLAND AREAS UNDER
WEAKENING HIGH PRESSURE WITH SLOW COOLING SPREADING INLAND SLOWLY
FROM THE COAST. FOR LATE WEDNESDAY NIGHT THROUGH THURSDAY...A TROUGH
OF LOW PRESSURE WILL BRING PRECIPITATION TO MOST AREAS FROM THE
COAST TO THE MOUNTAINS. DRY FOR FRIDAY AND EARLY SATURDAY UNDER WEAK
HIGH PRESSURE...THEN ANOTHER CHANCE FOR SHOWERS FOR LATE SATURDAY
INTO SUNDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH THURSDAY)...
HIGH PRESSURE WILL SLOWLY WEAKEN THROUGH WEDNESDAY WITH WEAK
OFFSHORE SURFACE FLOW. SLOW COOLING WILL BEGIN TO SPREAD INLAND FROM
THE COAST TODAY AND WEDNESDAY AND SOME PATCHY STRATUS MAY RETURN
NEAR THE COAST TONIGHT INTO WEDNESDAY MORNING. THERE WILL CONTINUE
TO BE A FLOW OF MOISTURE ALOFT FROM THE SOUTH BRINGING SOME HIGH
CLOUDS. THE ECMWF IS GENERALLY FAVORED WITH THE SYSTEM FOR WEDNESDAY
NIGHT AND THURSDAY...ESPECIALLY WITH THE INTENSITY. IT SHOULD BE
NOTED THAT THE GFS AND NAM ARE NOW TRENDING CLOSER TO THE PREFERRED
ECMWF (I.E. WEAKER AND SLOWER). THIS WOULD BRING PRECIPITATION TO
MOST AREAS FROM THE COAST TO THE MOUNTAINS FOR LATE WEDNESDAY NIGHT
THROUGH THURSDAY MORNING. POPS HAVE BEEN INCREASED CLOSER TO THE
SREF. AMOUNTS ARE EXPECTED TO RANGE FROM AROUND ONE QUARTER INCH AT
THE COAST TO ONE HALF INCH ON THE COASTAL MOUNTAIN SLOPES.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
ECMWF PREFERRED THROUGH THE EXTENDED. WEAK SHORTWAVE RIDGING SHOULD
BRING DRYING AND MINOR WARMING FOR FRIDAY AND EARLY SATURDAY THOUGH
STILL WITH A DECENT AMOUNT OF CLOUDS. A TROUGH OF LOW PRESSURE IN
NORTHWEST FLOW MAY BRING A CHANCE OF PRECIPITATION LATE IN THE
WEEKEND WITH COOLER MOIST CYCLONIC FLOW CONTINUING INTO MONDAY.
&&
.AVIATION...
201000Z...EXPECT MID 15K TO HIGH 20K BROKEN TO OVERCAST CLOUDS TODAY
THROUGH THIS EVENING...OTHERWISE VFR. LOCAL GUSTY NE WINDS TO 25 KT
BELOW PASSES WILL CONTINUE THIS MORNING THEN DECREASE. MID CLOUDS
WILL THICKEN AND LOWER TO 10K FEET LATE TONIGHT THROUGH WED MORNING
AS AN UPPER LOW APPROACHES FROM THE WEST...WITH A CHANCE OF
SCATTERED LIGHT SHOWERS DEVELOPING BY MID DAY WED.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 200431
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST MON JAN 19 2009
.SYNOPSIS...WEAKENING HIGH PRESSURE WILL CONTINUE FAIR WEATHER
THROUGH TUESDAY EXCEPT FOR PATCHY COASTAL LOW CLOUDS AND FOG DURING
THE NIGHTS AND MORNINGS. A COUPLE OF UPPER LEVEL LOW PRESSURE
SYSTEMS WILL BRING MORE CLOUDS AND COOLING DURING THE SECOND HALF OF
THE WEEK WITH A CHANCE OF SHOWERS LATE WEDNESDAY INTO THURSDAY AND
NEXT WEEKEND.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT THROUGH THURSDAY)...THERE WAS VARIABLE MID TO
HIGH CLOUDINESS THIS EVENING AND PATCHES OF STRATUS OFFSHORE. THE
00Z NKX SOUNDING WAS DRY IN THE LOW LEVELS BUT SHOWED THE MID TO
HIGH LEVEL MOISTURE IN SW WINDS ALOFT. WEAKENING OFFSHORE GRADIENTS
WITH ABOUT -10 MB SAN-TPH.
LOCAL DENSE FOG COULD DEVELOP NEAR THE COAST LATE TONIGHT...BUT
OFFSHORE FLOW WILL KEEP IT PATCHY AND CONFINED TO THE SAN DIEGO
COASTAL AREAS. WEAKENING HIGH PRESSURE ALOFT AND WEAKENING OFFSHORE
FLOW WILL RESULT IN A LITTLE COOLING TUE. THERE WILL ALSO CONTINUE
TO BE VARIABLE HIGH CLOUDINESS FLOWING UP FROM THE SW. AN UPPER
TROUGH APPROACHING FROM THE WNW WILL BRING MORE CLOUDS AND COOLING
WEDNESDAY WITH A DEEPENING MARINE LAYER. THIS TROUGH WILL MAKE
SHOWERS LIKELY LATE WEDNESDAY INTO THURSDAY. RAINFALL TOTALS SHOULD
RANGE FROM ABOUT A QUARTER INCH OR LESS NEAR THE COAST UP TO ABOUT
HALF AN INCH ON THE COASTAL MOUNTAIN SLOPES WITH LITTLE OR NO RAIN
EXPECTED IN THE DESERTS. WEAK SHORT WAVE RIDGING WILL BRING AN END
TO THE PRECIP LATE THURSDAY. MAX TEMPS ABOUT 6 TO 12 DEGREES ABOVE
SEASONAL TUESDAY WILL LOWER TO NEAR OR A LITTLE BELOW SEASONAL
AVERAGES BY THURSDAY.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...RESIDUAL MOISTURE COMBINED WITH
SW FLOW ALOFT AHEAD OF ANOTHER TROUGH WILL CONTINUE PARTLY CLOUDY
SKIES AND A SMALL CHANCE OF SHOWERS WITH LITTLE TEMP CHANGE FRIDAY.
THIS NEXT TROUGH SHOULD SPLIT AS IT MOVES ACROSS THE W COAST WITH
ENOUGH ENERGY MOVING ONSHORE FOR ANOTHER CHANCE OF SHOWERS SATURDAY
INTO SUNDAY. HOWEVER...THE TIMING AND STRENGTH REMAIN UNCERTAIN. THE
THREAT OF SHOWERS SHOULD END BY MONDAY IN DRIER NW FLOW. BELOW
SEASONAL TEMPS IN MOST AREAS...ESPECIALLY SUNDAY AND MONDAY WHEN MAX
TEMPS SHOULD BE ABOUT 5 TO 10 DEGREES BELOW AVERAGE.
&&
.AVIATION...
200411Z...WEAK ONSHORE FLOW EARLIER TODAY PUSHED UP RH AT THE
IMMEDIATE COAST. ELEVATED DEWPOINTS THIS EVENING COULD RESULT IN
SOME PATCHY DENSE FOG AT THE BEACHES AND NEAR COASTAL AIRPORTS.
HOWEVER...DEVELOPING COLD AIR DRAINAGE DURING THE NIGHT SHOULD KEEP
IT AWAY FROM THE COASTAL AIRPORTS. VFR CONDITIONS SHOULD PREVAIL
THROUGH TUE WITH AREAS OF CIGS ABOVE FL150 POSSIBLE AT TIMES. ONLY
OTHER CONCERN IS FOR LOCAL LOW LEVEL WIND SHEAR WHICH COULD
DEVELOP...ESPECIALLY BELOW MOUNTAIN PASSES AND CANYONS...DUE TO
GUSTY OFFSHORE WINDS TO 25 KT AT TIMES.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...JAD
000
FXUS66 KSGX 192129
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
130 PM PST MON JAN 19 2009
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL SLOWLY WEAKEN THROUGH TUESDAY WITH WEAK
OFFSHORE FLOW WITH SLOW COOLING AND A GRADUAL RETURN OF THE MARINE
LAYER FOR TUESDAY AND WEDNESDAY. FOR WEDNESDAY NIGHT AND EARLY
THURSDAY...A WEAK TROUGH WILL BRING COOLING... CLOUDS...AND A CHANCE
OF MAINLY LIGHT PRECIPITATION. A STRONGER TROUGH OF LOW PRESSURE MAY
BRING ANOTHER CHANCE OF PRECIPITATION LATE SATURDAY INTO EARLY
SUNDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM...TONIGHT THROUGH THURSDAY...
ANOTHER BEAUTIFUL DAY ACROSS SOUTHERN CALIFORNIA...ABOUT THE TENTH
DAY IN A ROW OF ABOVE NORMAL TEMPERATURES UNDER THE STRONG HIGH
PRESSURE RIDGE AND WEAK TO MODERATE SANTA ANA WINDS BUT THESE
CONDITIONS WILL BE COMING TO AN END. THE OFFSHORE WINDS PEAKED
AROUND 10 AM WITH GUSTS AROUND 40 MPH IN THE WIND PRONE AREAS. SINCE
NOON GUSTS HAVE DROPPED BELOW 25 MPH. TEMPERATURES THIS AFTERNOON
ALONG THE COAST ARE DOWN ABOUT 5 TO 10 DEGREES FROM
YESTERDAY...PARTLY OWING TO THE HIGH CLOUDS THAT MOVED ACROSS THIS
MORNING AND PARTLY TO THE EARLIER ONSET OF THE SEA BREEZE. THERE IS
THE POSSIBILTY OF DENSE FOG THIS EVENING OVER COASTAL WATERS/SAN
DIEGO COUNTY COAST IF DEW POINTS CLIMB INTO THE UPPER 50S BEFORE
SUNSET AND TRENDS SEEM TO BE SUPPORTING THIS. HOWEVER THE PREVAILING
OFFSHORE SYNOPTIC FLOW WILL LIKELY ADD TO THE LAND BREEZES
DEVELOPING AROUND 0200 PST AND BRING IN DRIER AIR...WITH THE EDGE OF
STRATUS/FOG BANK RETREATING BACK TO SEA EARLY TUESDAY MORNING.
HOWEVER BY TUESDAY AFTERNOON AND THROUGH WEDNESDAY...THE OFFSHORE
SYNOPTIC FLOW HAS WEAKENED AND TURNED SOUTHEAST IN THE LOWER 5000
FEET AND WEAK SURFACE CONVERGENCE IS PRESENT ALONG OR JUST INLAND.
THESE FACTORS ARE FAVORABLE FOR MAINTAINING A SHALLOW MARINE LAYER
AND DEVELOPING STRATUS/FOG ALONG BOTH SAN DIEGO AND ORANGE COUNTY
COASTS. THE ONLY OPPOSING FACTOR BEING ANY GREENHOUSE EFFECT FROM
OPAQUE HIGH CLOUDS THAT WOULD KEEP THE MARINE LAYER FROM COOLING TO
SATURATION OVERNIGHT. EITHER WAY VISIBILITY WILL BE NOTICEABLE LOWER
AND TEMPERATURES RETURNING TO NORMAL OVER THE COASTAL AREAS. THOUGH
THE SURFACE HIGH PRESSURE CENTERED OVER THE GREAT BASIN AND THE HIGH
PRESSURE RIDGE ALOFT ARE BOTH WEAKENING...THROUGH WEDNESDAY THEY
WILL CONTINUE TO DOMINATE THE WEATHER PATTERN FOR THE REMAINDER OF
SOUTHWEST CALIFORNIA. THE MID AND UPPER LAYERS...ABOVE 8000 FEET
ELEVATION WILL BECOME MOIST DUE TO THE INCREASING CYCLONIC FLOW
ALOFT AND ADDITIONAL ENTRAINMENT FROM THE SOUTH. THIS WILL RESULT IN
OCCASIONAL HIGH CLOUDS. THESE AND THE DECREASING 1000-500 MB
THICKNESS VALUES WILL RESULT IN MODERATING TEMPERATURES BACK TO
NORMAL. FOR WEDNESDAY NIGHT INTO THURSDAY...THE MODELS FORECAST THE
WESTERLIES TO ALMOST FINISH UNDERCUTTING THE RIDGE AND RUN A SHORT
WAVE UP AGAINST THE COAST...THEN WEAKEN IT RAPIDLY AS IT MOVES
INLAND ACROSS SOUTHERN CALIFORNIA. THE MARINE LAYER IS FORECAST TO
RAPIDLY DEEPEN AND MERGE WITH THE INCREASING MID/HIGH LEVEL MOISTURE
ASSOCIATED WITH THE TROUGH. THE LIFTING OF THE SATURATED AIR MASS
SHOULD RESULT IN DRIZZLE/LIGHT RAIN FROM MOUNTAINS/WESTWARD
WEDNESDAY NIGHT INTO THURSDAY. ADJUSTED POPS AND QPF AMOUNTS
SLIGHTLY FROM EARLIER FORECAST AND RAISED SNOW LEVELS TO AGREE WITH
ADJACENT OFFICES. NEXT SHIFT MAY MAKE FURTHER ADJUSTMENTS BEFORE
AFTERNOON QPSSGX IS SENT.
&&
.LONG TERM FRIDAY THROUGH MONDAY JANUARY 26...
WITH THE RIDGE NOW GREATLY WEAKENED...ANOTHER SHORT WAVE TROUGH IS
CARRIED ONSHORE BY THE WEEKEND. MODELS ARE DIVERGENT SO FORECASTER
CONFIDENCE IS LOW. CONSENSUS BY NCEP HPC AND CALIFORNIA-NEVADA RIVER
FORECAST CENTER IS TO GO WITH UKMET SOLUTION. ASIDE FROM SOME
DEWPOINT/RH ADJUSTMENTS MADE NO CHANGES TO GRIDS FOR THIS PERIOD.
&&
.AVIATION...
192130Z...MOSTLY CLEAR AND VFR CONDITIONS WILL CONTINUE WITH AN
OCCASIONAL CLOUD DECK BETWEEN 10K AND 20K FEET THROUGH TUESDAY.
LOCALLY DENSE FOG IS POSSIBLE ALONG THE COAST BETWEEN ABOUT 03Z-11Z
MAINLY AROUND SAN AND/OR CRQ WITH CEILINGS BELOW 500 FEET AND VIS
BELOW 1/2 MILE. THE OFFSHORE FLOW SHOULD PUSH THE FOG BACK OUT TO
SEA AFTER 11Z TUESDAY. OFFSHORE BREEZES WILL BE STRONGEST AFTER
SUNRISE TUESDAY WITH GUSTS TO 25 KT BELOW PASSES.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH RIP CURRENT RISK ORANGE COUNTY AND SAN DIEGO COUNTY
BEACHES THROUGH TUESDAY.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...BALFOUR
AVIATION/MARINE...MM
SPECIAL NOTE...THE WEATHER.GOV WEBPAGE IS DOWN. ESTIMATED TIME OF
REPAIR UNKNOWN.
000
FXUS66 KSGX 191628
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
830 AM PST MON JAN 19 2009
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL SLOWLY WEAKEN THROUGH TUESDAY WITH WEAK
OFFSHORE FLOW WITH SLOW COOLING AND A GRADUAL RETURN OF THE MARINE
LAYER FOR TUESDAY AND WEDNESDAY. FOR WEDNESDAY NIGHT AND EARLY
THURSDAY...A WEAK TROUGH WILL BRING COOLING... CLOUDS...AND A CHANCE
OF MAINLY LIGHT PRECIPITATION. A STRONGER TROUGH OF LOW PRESSURE MAY
BRING ANOTHER CHANCE OF PRECIPITATION LATE SATURDAY INTO EARLY
SUNDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
HIGH PRESSURE ALOFT HAS ALMOST PINCHED OFF AND IS SHIFTING EASTWARD.
THIS HAS RESULTED IN SOUTHEAST FLOW IN THE MID AND UPPER LEVELS OVER
SOUTHERN CALIFORNIA THAT HAS BROUGHT UP SUBTROPICAL MOISTURE. THE
RADARS ARE PICKING UP ECHOES BETWEEN 12000-20000 FEET BUT THE LOW
LEVELS REMAIN EXTREMELY DRY BELOW 6000 FEET DUE TO THE CONTINUING
WEAK SANTA ANA WINDS AND STRONG OFFSHORE PRESSURE GRADIENT - 19 MB
FROM NEVADA TO SW CALIFORNIA COAST. THE COMBINATION OF OPAQUE HIGH
CLOUDS AND EAST TO NORTHEAST WINDS IN THIS LOWER LAYER KEPT
TEMPERATURES QUITE WARM OVERNIGHT...STAYING MOSTLY IN THE MID 50S
AND 60S...WHILE MOUNTAIN VALLEYS/DESERTS WERE ABOUT 10 DEGREES
WARMER OWING TO THE HIGH CLOUDS. THE OTHER NOTICEABLE CHANGE THAT
THIS HIGH LEVEL MOISTURE HAS BROUGHT ARE SPECTACULARLY BEAUTIFUL
SUNSETS AND SUNRISES. THE LOW LEVELS...AWAY FROM THE COAST AND BELOW
8000 FEET WILL REMAIN QUITE DRY UNDER THE CONTINUING OFFSHORE FLOW
THROUGH AT LEAST WEDNESDAY AND THE MID AND UPPER LAYERS REMAIN
RELATIVELY MOIST WITH OCCASIONAL HIGH CLOUDS DUE TO THE INCREASING
CYCLONIC FLOW ALOFT AND ADDITIONAL ENTRAINMENT FROM THE SOUTH. THE
BIG CHANGE DURING THIS PERIOD WILL BE ALONG THE COAST WITH THE
RE-ESTABLISHMENT OF A MARINE LAYER. AGREE WITH PREVIOUS FORECASTERS
ASSESSMENT OF POSSIBILTY OF DENSE FOG THIS EVENING OVER COASTAL
WATERS/SAN DIEGO COUNTY COAST AND THIS BEING A DISCONTINUOUS PROCESS
DUE TO THE OFFSHORE FLOW ADDING TO THE LAND BREEZE COMPONENT PUSHING
THE STRATUS/FOG BANK BACK OFF THE COAST TUESDAY MORNING...BUT BY
TUESDAY AFTERNOON AND THROUGH WEDNESDAY...WEAK SURFACE CONVERGENCE
ALONG OR JUST INLAND AND LIGHT SOUTHEAST FLOW IN THE LOWER 5000 FEET
ARE FAVORABLE FOR MAINTAINING A SHALLOW MARINE LAYER...BELOW 300
FEET...AND DEVELOPING STRATUS/FOG ALONG BOTH ALONG SAN DIEGO AND
ORANGE COUNTY COASTS. THE ONLY OPPOSING FACTOR BEING ANY GREENHOUSE
EFFECT FROM OPAQUE HIGH CLOUDS THAT WOULD KEEP THE MARINE LAYER FROM
COOLING TO SATURATION OVERNIGHT. EITHER WAY VISIBILITY WILL BE
NOTICEABLE LOWER AND TEMPERATURES RETURNING TO NORMAL OVER THE NEXT
SEVERAL DAYS.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
THE MODELS FORECAST THE MARINE LAYER TO RAPIDLY DEEPEN AND MERGE
WITH A PROGRESSIVELY LOWERING MID/HIGH CLOUD LAYER...AS THE
WESTERLIES ALMOST FINISH UNDERCUTTING THE RIDGE AND RUN A SHORT WAVE
UP AGAINST THE COAST BUT WEAKEN IT RAPIDLY AS IT MOVES IN. THE
LIFTING OF THE SATURATED AIR MASS SHOULD RESULT IN DRIZZLE/LIGHT
RAIN FROM MOUNTAINS/WESTWARD WEDNESDAY NIGHT INTO THURSDAY. THE
RIDGE NOW FURTHER WEAKENED...ANOTHER SHORT WAVE TROUGH IS CARRIED TO
THE COAST BY THE WEEKEND. MODELS ARE DIVERGENT SO FORECASTER
CONFIDENCE IS LOW. CONSENSUS BY NCEP HPC AND CALIFORNIA-NEVADA RIVER
FORECAST CENTER IS TO GO WITH UKMET SOLUTION. FROM PREVIOUS
DISCUSSION...FOR LATE THURSDAY THROUGH EARLY SATURDAY...WEAK
SHORTWAVE RIDGING SHOWN BY THE PREFERRED ECMWF SHOULD DECREASE
CLOUDS A LITTLE AND BRING MINOR WARMING FOR FRIDAY AND
SATURDAY...BUT LITTLE MORE THAN SEASONAL LEVELS. FOR LATE SATURDAY
AND SUNDAY...A STRONGER TROUGH OF LOW PRESSURE MAY BRING ANOTHER
CHANCE OF PRECIPITATION. GREATER CONFIDENCE...SUCH AS IT IS...IS
PLACED IN THE ECMWF AND TO SOME EXTEND WITH THE GFS ENSEMBLE MEAN
WITH THIS SYSTEM. THE ERRATIC GFS IS LARGELY DISCOUNTED.
&&
.AVIATION...
191600Z...EXPECT VARIABLE MID AND HIGH CLOUDS TODAY BETWEEN 10K AND
20K FEET...OTHERWISE VFR. LOCAL NE WINDS WITH GUSTS TO 25 KT BELOW
PASSES WILL CONTINUE THIS MORNING WITH A WEAKER VERSION EARLY
TUESDAY. LOCALLY DENSE FOG IS POSSIBLE ALONG THE COAST BETWEEN ABOUT
03Z-11Z MAINLY AROUND SAN AND/OR CRQ WITH CEILINGS BELOW 500 FEET
AND VIS BELOW 1/2 MILE. THE OFFSHORE FLOW SHOULD PUSH IT BACK OUT TO
SEA AFTER 11Z TUESDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH RIP CURRENT RISK ORANGE COUNTY AND SAN DIEGO COUNTY
BEACHES THROUGH TUESDAY.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...BALFOUR
AVIATION/MARINE...MM
SPECIAL NOTE...THE WEATHER.GOV WEBPAGE IS DOWN. ESTIMATED TIME OF
REPAIR UNKNOWN.
000
FXUS66 KSGX 191106
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
305 AM PST MON JAN 19 2009
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL SLOWLY WEAKEN THROUGH TUESDAY WITH WEAK
OFFSHORE FLOW WITH SLOW COOLING AND A GRADUAL RETURN OF THE MARINE
LAYER FOR TUESDAY AND WEDNESDAY. FOR LATE WEDNESDAY AND EARLY
THURSDAY...A WEAK TROUGH OF LOW PRESSURE WILL BRING COOLING...
CLOUDS...AND A CHANCE OF MAINLY LIGHT PRECIPITATION. A STRONGER
TROUGH OF LOW PRESSURE MAY BRING ANOTHER CHANCE OF PRECIPITATION
LATE SATURDAY INTO EARLY SUNDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
HIGH PRESSURE ALOFT OVER THE NORTHERN ROCKIES WILL WEAKEN AND MOVE
SOUTHEASTWARD INTO THE CENTRAL ROCKIES THROUGH TUESDAY. SURFACE HIGH
PRESSURE OVER THE GREAT BASIN WILL BRING WEAK OFFSHORE WINDS TO
INLAND AREAS AT TIMES INTO EARLY WEDNESDAY. HIGH TEMPERATURES WILL
COOL SLIGHTLY THROUGH TUESDAY WITH A LITTLE GREATER COOLING
WEDNESDAY. A SHALLOW MARINE LAYER MAY REDEVELOP TODAY WITH PATCHY
DENSE FOG POSSIBLY RETURNING TO THE COASTAL WATERS AND AREAS NEAR
THE COAST...MAINLY SAN DIEGO COUNTY...THIS EVENING. WITH WEAK
OFFSHORE FLOW AND LATE NIGHT OFFSHORE DRAINAGE FLOW...THIS DENSE FOG
MAY PULL BACK OFF THE COAST BY TUESDAY MORNING. AREAS OF LOW CLOUDS
AND FOG OVER THE COASTAL WATERS TUESDAY NIGHT AND WEDNESDAY MORNING
ARE EXPECTED TO EXTEND LOCALLY INLAND ALONG THE COAST.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
A WEAKENING TROUGH OF LOW PRESSURE FOR LATE WEDNESDAY THROUGH EARLY
THURSDAY IS EXPECTED TO BRING COOLING...MORE CLOUDS...AND A CHANCE
OF MAINLY LIGHT PRECIPITATION. THE ECMWF AND GFS ENSEMBLE MEAN ARE
PREFERRED WITH THE HANDLING OF THIS SYSTEM. FOR LATE THURSDAY
THROUGH EARLY SATURDAY...WEAK SHORTWAVE RIDGING SHOWN BY THE
PREFERRED ECMWF SHOULD DECREASE CLOUDS A LITTLE AND BRING MINOR
WARMING FOR FRIDAY AND SATURDAY...BUT LITTLE MORE THAN SEASONAL
LEVELS. FOR LATE SATURDAY AND SUNDAY...A STRONGER TROUGH OF LOW
PRESSURE MAY BRING ANOTHER CHANCE OF PRECIPITATION. GREATER
CONFIDENCE...SUCH AS IT IS...IS PLACED IN THE ECMWF AND TO SOME
EXTEND WITH THE GFS ENSEMBLE MEAN WITH THIS SYSTEM. THE ERRATIC GFS
IS LARGELY DISCOUNTED.
&&
.AVIATION...
191000Z...VARIABLE MID AND HIGH CLOUDS TODAY BETWEEN 15K AND 20K
FEET OTHERWISE VFR. LOCAL GUSTY NE WINDS TO 25 KT BELOW PASSES WILL
CONTINUE TODAY THROUGH TUESDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 190431
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST SUN JAN 18 2009
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE WARM DAYS THROUGH TUESDAY
WITH VARIABLE HIGH CLOUDINESS. A COUPLE OF UPPER LEVEL LOW PRESSURE
SYSTEMS WILL BRING MORE CLOUDS AND COOLING DURING THE SECOND HALF OF
THE WEEK WITH A CHANCE OF SHOWERS LATE WEDNESDAY INTO THURSDAY AND
AGAIN TOWARD THE WEEKEND.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...HIGH CLOUDS WERE MOVING UP
FROM THE SW THIS EVENING. THE 00Z NKX SOUNDING WAS DRY IN THE LOW
LEVEL BUT SHOWED THE HIGH LEVEL MOISTURE IN SW FLOW. OFFSHORE
GRADIENTS WITH ABOUT -12 MB SAN-TPH.
A HIGH AMPLITUDE RIDGE ALOFT WILL SLOWLY SHIFT E AND OFFSHORE FLOW
WILL GRADUALLY WEAKEN THROUGH TUESDAY. THIS WILL CONTINUE WARM DAYS
WITH MAX TEMPS ABOUT 8 TO 12 DEGREES ABOVE SEASONAL AVERAGES IN MOST
AREAS. THE OFFSHORE FLOW WILL CAUSE LOCAL BREEZY CONDITIONS THROUGH
AND BELOW MOUNTAIN CANYONS AND PASSES THROUGH MONDAY MORNING. THE
OFFSHORE FLOW SHOULD WEAKEN ENOUGH TO ALLOW PATCHY LOW CLOUDS AND
FOG TO RETURN TO THE COAST AS EARLY AS MONDAY NIGHT AND TUESDAY
MORNING. FOG COULD BE LOCALLY DENSE WHEN THE STRATUS RETURNS. A
TROUGH APPROACHING FROM THE WNW WILL BRING MORE CLOUDS AND COOLING
WEDNESDAY WITH A SLIGHT CHANCE OF SHOWERS LATE IN THE DAY. THE
CHANCE OF SHOWERS WILL INCREASE A LITTLE OVERNIGHT. TEMPS WILL BE
NEAR OR SLIGHTLY BELOW SEASONAL WEDNESDAY. RAINFALL TOTALS SHOULD
GENERALLY BE LESS THAN A THIRD OF AN INCH. THE SNOW LEVEL REMAIN
ABOVE 6500 FT N AND 7000 FT S.
&&
.LONG TERM (THURSDAY THROUGH SUNDAY)...PARTLY CLOUDY SKIES AND A FEW
SHOWERS COULD LINGER INTO THURSDAY MORNING. DRY FRIDAY UNDER A SHORT
WAVE RIDGE. TEMPS SHOULD REMAIN NEAR OR A LITTLE BELOW SEASONAL
AVERAGES THURSDAY AND FRIDAY. ANOTHER TROUGH WILL BRING MORE COOLING
WITH A SMALL CHANCE OF SHOWERS OVER THE WEEKEND.
&&
.AVIATION...
190310Z...INCREASING CLOUDS ABOVE FL200 THROUGH MONDAY...OTHERWISE
VFR. LOCAL LOW LEVEL WIND SHEAR POSSIBLE...ESPECIALLY BELOW
MOUNTAIN PASSES AND CANYONS DUE TO GUSTY OFFSHORE WINDS TO 25 KT AT
TIMES.
&&
.MARINE...
WEST SWELL 4 TO 6 FEET WILL RESULT IN HIGHER THAN NORMAL SURF AND
STRONG RIP CURRENTS FOR THE NEXT SEVERAL DAYS. LARGER WAVES MAY
AFFECT ENTRANCES TO BAYS AND HARBORS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...JAD
000
FXUS66 KSGX 190031 AAA
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
430 PM PST SUN JAN 18 2009
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT OVER THE WEST COAST COMBINED WITH SURFACE
HIGH PRESSURE OVER THE PLATEAU WILL CONTINUE TO BRING OFFSHORE FLOW
TO THE AREA THROUGH TUESDAY. ONSHORE FLOW WILL BEGIN WEDNESDAY
LEADING TO A INCREASING CLOUDS...COOLER CONDITIONS...AND THE
POSSIBILITY OF RAIN WEDNESDAY NIGHT INTO THURSDAY. ANOTHER
POSSIBILITY OF RAIN WILL DEVELOP OVER THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A HUGE BLOCKING HIGH CONTINUES TO BACK UP STORM TRAFFIC OVER THE
PACIFIC...FOR CONTINUED UNSEASONABLY WARM CONDITIONS OVER THE
SOUTHWEST COAST OF CALIFORNIA. THIS STRONG UPPER LEVEL HIGH PRESSURE
OVER THE WEST COAST WILL HANG ON FOR AT LEAST A COUPLE MORE DAYS AND
KEEP THE WARM SPELL GOING. AFTERNOON HIGH TEMPERATURES AT ABOUT 10
DEGREES ABOVE NORMAL OR SO...IN THE 70S AND 80S...SHOULD BE THE RULE
COASTAL MOUNTAIN SLOPES WESTWARD. SOME OF THE ENERGY FROM THE STORMS
HAS BEEN ABLE TO CUT UNDER THE RIDGE AND DRIVING SOME LARGE SURF.
SOME WEAK OFFSHORE WINDS...STRONGEST IN THE MORNINGS...IS EXPECTED
BELOW CANYONS AND PASSES.
MONDAY NIGHT THE STRATUS MAY REDEVELOP OVER THE COASTAL WATERS AND
EXTEND LOCALLY INLAND IN THE FORM OF DENSE FOG...PERHAPS PULLING
BACK OFF THE COAST BY TUESDAY MORNING...NUDGED WESTWARD BY A
COMBINATION OF WEAK DRAINAGE AND WEAK OFFSHORE FLOW.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
THE LATEST MAPS SHOW THAT THERE SHOULD BE SOME WEAK STORMS CUTTING
UNDER THE RIDGE AND HEADING TOWARD SOUTHERN CALIFORNIA LATE IN THE
WEEK. RAIN IS POSSIBLE WEDNESDAY EVENING...AND A BETTER POSSIBILITY
EARLY THURSDAY MORNING. AFTER COORD WITH LOX...BOOSTED RAINFALL INTO
THE CHANCE CATEGORY COASTAL SLOPES WESTWARD FOR LATE WEDNESDAY
NIGHT. BREEZY CONDITIONS MOUNTAINS AND DESERTS WEDNESDAY THROUGH
EARLY THURSDAY.
A SECOND...POSSIBLY STRONGER SYSTEM FOR THE WEEKEND MAY BRING
ADDITIONAL COOLING AND GREATER POSSIBILITIES FOR RAIN TO DEVELOP.
&&
.AVIATION...
182000Z...MOSTLY CLEAR EXCEPT SOME CIRRUS ABOVE FL250 TODAY...
INCREASING TONIGHT THROUGH MONDAY. SOME GUSTY NORTHEAST WINDS TO 25
KT INLAND VALLEYS THROUGH CANYONS AND PASSES AND OVER MOUNTAINS...
MAINLY VICINITY KONT AND SOME WIND POSSIBLE AT KSNA. HORTON
&&
.MARINE...
WEST NORTHWEST SWELL NOT EXPECTED TO INCREASE MUCH MORE. LARGER
WAVES MAY AFFECT ENTRANCES TO BAYS AND HARBORS. SURF SHOULD BEGIN TO
SUBSIDE DURING THE AFTERNOON ON MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...SMALL/ATKIN
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 190030
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PST SUN JAN 18 2009
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT OVER THE WEST COAST COMBINED WITH SURFACE
HIGH PRESSURE OVER THE PLATEAU WILL CONTINUE TO BRING OFFSHORE FLOW
TO THE AREA THROUGH TUESDAY. ONSHORE FLOW WILL BEGIN WEDNESDAY
LEADING TO A INCREASING CLOUDS...COOLER CONDITIONS...AND THE
POSSIBILITY OF RAIN WEDNESDAY NIGHT INTO THURSDAY. ANOTHER
POSSIBILITY OF RAIN WILL DEVELOP OVER THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A HUGE BLOCKING HIGH CONTINUES TO BACK UP STORM TRAFFIC OVER THE
PACIFIC...FOR CONTINUED UNSEASONABLY WARM CONDITIONS OVER THE
SOUTHWEST COAST OF CALIFORNIA. THIS STRONG UPPER LEVEL HIGH PRESSURE
OVER THE WEST COAST WILL HANG ON FOR AT LEAST A COUPLE MORE DAYS AND
KEEP THE WARM SPELL GOING. AFTERNOON HIGH TEMPERATURES AT ABOUT 10
DEGREES ABOVE NORMAL OR SO...IN THE 70S AND 80S...SHOULD BE THE RULE
COASTAL MOUNTAIN SLOPES WESTWARD. SOME OF THE ENERGY FROM THE STORMS
HAS BEEN ABLE TO CUT UNDER THE RIDGE AND DRIVING SOME LARGE SURF.
SOME WEAK OFFSHORE WINDS...STRONGEST IN THE MORNINGS...IS EXPECTED
BELOW CANYONS AND PASSES.
MONDAY NIGHT THE STRATUS MAY REDEVELOP OVER THE COASTAL WATERS AND
EXTEND LOCALLY INLAND IN THE FORM OF DENSE FOG...PERHAPS PULLING
BACK OFF THE COAST BY TUESDAY MORNING...NUDGED WESTWARD BY A
COMBINATION OF WEAK DRAINAGE AND WEAK OFFSHORE FLOW.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
THE LATEST MAPS SHOW THAT THERE SHOULD BE SOME WEAK STORMS CUTTING
UNDER THE RIDGE AND HEADING TOWARD SOUTHERN CALIFORNIA LATE IN THE
WEEK. RAIN IS POSSIBLE WEDNESDAY EVENING...AND A BETTER POSSIBILITY
EARLY THURSDAY MORNING. AFTER COORD WITH LOX...BOOSTED RAINFALL INTO
THE CHANCE CATEGORY COASTAL SLOPES WESTWARD FOR LATE WEDNESDAY
NIGHT. BREEZY CONDITIONS MOUNTAINS AND DESERTS WEDNESDAY THROUGH
EARLY THURSDAY.
A SECOND...POSSIBLY STRONGER SYSTEM FOR THE WEEKEND MAY BRING
ADDITIONAL COOLING AND GREATER POSSIBILITIES FOR RAIN TO DEVELOP.
&&
.AVIATION...
182000Z...MOSTLY CLEAR EXCEPT SOME CIRRUS ABOVE FL250 TODAY...
INCREASING TONIGHT THROUGH MONDAY. SOME GUSTY NORTHEAST WINDS TO 25
KT INLAND VALLEYS THROUGH CANYONS AND PASSES AND OVER MOUNTAINS...
MAINLY VICINITY KONT AND SOME WIND POSSIBLE AT KSNA. HORTON
&&
.MARINE...
WEST NORTHWEST SWELL NOT EXPECTED TO INCREASE MUCH MORE. HIGH SURF
POSSIBLE ALONG SAN DIEGO COUNTY COAST...MAINLY SOUTH. LARGER WAVES
MAY AFFECT ENTRANCES TO BAYS AND HARBORS. SURF SHOULD BEGIN TO
SUBSIDE DURING THE AFTERNOON ON MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...SMALL
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 182139
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PST SUN JAN 18 2009
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT OVER THE WEST COAST COMBINED WITH SURFACE
HIGH PRESSURE OVER THE PLATEAU WILL CONTINUE TO BRING OFFSHORE FLOW
TO THE AREA THROUGH TUESDAY. ONSHORE FLOW WILL BEGIN WEDNESDAY
LEADING TO A INCREASING CLOUDS...COOLER CONDITIONS...AND THE
POSSIBILITY OF RAIN WEDNESDAY NIGHT INTO THURSDAY. ANOTHER
POSSIBILITY OF RAIN WILL DEVELOP OVER THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
A HUGE BLOCKING HIGH CONTINUES TO BACK UP STORM TRAFFIC OVER THE
PACIFIC...FOR CONTINUED UNSEASONABLY WARM CONDITIONS OVER THE
SOUTHWEST COAST OF CALIFORNIA. THIS STRONG UPPER LEVEL HIGH PRESSURE
OVER THE WEST COAST WILL HANG ON FOR AT LEAST A COUPLE MORE DAYS AND
KEEP THE WARM SPELL GOING. AFTERNOON HIGH TEMPERATURES AT ABOUT 10
DEGREES ABOVE NORMAL OR SO...IN THE 70S AND 80S...SHOULD BE THE RULE
COASTAL MOUNTAIN SLOPES WESTWARD. SOME OF THE ENERGY FROM THE STORMS
HAS BEEN ABLE TO CUT UNDER THE RIDGE AND DRIVING SOME LARGE SURF.
SOME WEAK OFFSHORE WINDS...STRONGEST IN THE MORNINGS...IS EXPECTED
BELOW CANYONS AND PASSES.
MONDAY NIGHT THE STRATUS MAY REDEVELOP OVER THE COASTAL WATERS AND
EXTEND LOCALLY INLAND IN THE FORM OF DENSE FOG...PERHAPS PULLING
BACK OFF THE COAST BY TUESDAY MORNING...NUDGED WESTWARD BY A
COMBINATION OF WEAK DRAINAGE AND WEAK OFFSHORE FLOW.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
THE LATEST MAPS SHOW THAT THERE SHOULD BE SOME WEAK STORMS CUTTING
UNDER THE RIDGE AND HEADING TOWARD SOUTHERN CALIFORNIA LATE IN THE
WEEK. RAIN IS POSSIBLE WEDNESDAY EVENING...AND A BETTER POSSIBILITY
EARLY THURSDAY MORNING. AFTER COORD WITH LOX...BOOSTED RAINFALL INTO
THE CHANCE CATEGORY COASTAL SLOPES WESTWARD FOR LATE WEDNESDAY
NIGHT. BREEZY CONDITIONS MOUNTAINS AND DESERTS WEDNESDAY THROUGH
EARLY THURSDAY.
A SECOND...POSSIBLY STRONGER SYSTEM FOR THE WEEKEND MAY BRING
ADDITIONAL COOLING AND GREATER POSSIBILITIES FOR RAIN TO DEVELOP.
&&
.AVIATION...
182000Z...MOSTLY CLEAR EXCEPT SOME CIRRUS ABOVE FL250 TODAY...
INCREASING TONIGHT THROUGH MONDAY. SOME GUSTY NORTHEAST WINDS TO 25
KT INLAND VALLEYS THROUGH CANYONS AND PASSES AND OVER MOUNTAINS...
MAINLY VICINITY KONT AND SOME WIND POSSIBLE AT KSNA. HORTON
&&
.MARINE...
WEST NORTHWEST SWELL NOT EXPECTED TO INCREASE MUCH MORE. HIGH SURF
POSSIBLE ALONG SAN DIEGO COUNTY COAST...MAINLY SOUTH. LARGER WAVES
MAY AFFECT ENTRANCES TO BAYS AND HARBORS. SURF SHOULD BEGIN TO
SUBSIDE DURING THE AFTERNOON ON MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...SMALL
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 181733
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
830 AM PST SUN JAN 18 2009
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER THE WEST COAST ALONG WITH A SURFACE
HIGH PRESSURE AREA OVER THE NORTHERN ROCKIES WILL SLOWLY WEAKEN AND
PUSH EAST THROUGH TUESDAY. LOW PRESSURE WILL DEVELOP OFF THE WEST
COAST AND BEGIN TO MOVE INLAND THE LATTER HALF OF THE WEEK. WELL
ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS WILL PREVAIL INTO
MONDAY WITH WEAK OFFSHORE FLOW AT TIMES. ONSHORE FLOW WILL RETURN
FOR THE LATTER HALF OF THE WEEK BRINGING COOLING... MORE
CLOUDS...AND SOME CHANCE FOR PRECIPITATION BY LATE IN THE WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
UNSEASONABLY STRONG UPPER LEVEL HIGH PRESSURE OVER THE WEST COAST
WILL HANG ON FOR AT LEAST A COUPLE MORE DAYS AND KEEP THE WARM SPELL
GOING. AFTERNOON HIGH TEMPERATURES AT ABOUT 10 DEGREES ABOVE NORMAL
OR SO...IN THE 70S AND 80S...SHOULD BE THE RULE IN THE BASIN.
THE STORMS HAVE BEEN CRASHING INTO THE WESTERN SIDE OF THE RIDGE...
BUT THE ONLY ENERGY THAT HAS BEEN ABLE TO CUT UNDER IS THE ENERGY
DRIVING THE LARGE SURF. SOME WEAK OFFSHORE WINDS...STRONGEST IN THE
MORNINGS...IS EXPECTED BELOW CANYONS AND PASSES.
MONDAY NIGHT THE STRATUS MAY REDEVELOP OVER THE COASTAL WATERS AND
EXTEND LOCALLY INLAND IN THE FORM OF DENSE FOG...PERHAPS PULLING
BACK OFF THE COAST BY TUESDAY MORNING...NUDGED WESTWARD BY A
COMBINATION OF WEAK DRAINAGE AND WEAK OFFSHORE FLOW.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
THE LATEST MAPS SHOW THAT THERE SHOULD BE SOME WEAK STORMS CUTTING
UNDER THE RIDGE AND HEADING TOWARD SOUTHERN CALIFORNIA LATE IN THE
WEEK. THERE IS A SMALL CHANCE OF RAIN AROUND THURSDAY...BUT DRY TIL
THEN. A SECOND POSSIBLY STRONGER SYSTEM FOR THE WEEKEND MAY BRING
ADDITIONAL COOLING AND GREATER CHANCES FOR PRECIPITATION.
&&
.AVIATION...
181430Z...MOSTLY CLEAR EXCEPT SOME CIRRUS ABOVE FL250 TODAY...
INCREASING TONIGHT THROUGH MONDAY. SOME GUSTY NORTHEAST WINDS TO 25
KT INLAND VALLEYS THROUGH CANYONS AND PASSES AND OVER MOUNTAINS...
MAINLY AT ONT AND SOME WIND POSSIBLE AT SNA. HORTON
&&
.MARINE...
WEST NORTHWEST SWELL NOT EXPECTED TO INCREASE MUCH MORE. HIGH SURF
POSSIBLE ALONG SAN DIEGO COUNTY COAST...MAINLY SOUTH. LARGER WAVES
MAY AFFECT ENTRANCES TO BAYS AND HARBORS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...SMALL
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 181029
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 AM PST SUN JAN 18 2009
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHERN ROCKIES WILL SLOWLY WEAKEN THROUGH
TUESDAY AS LOW PRESSURE DEVELOPS OFF THE WEST COAST AND BEGINS TO
MOVE INLAND THE LATTER HALF OF THE WEEK. WARM AND DRY CONDITIONS
WILL PREVAIL INTO MONDAY WITH WEAK OFFSHORE FLOW AT TIMES. ONSHORE
FLOW WILL RETURN FOR THE LATTER HALF OF THE WEEK BRINGING COOLING...
MORE CLOUDS...AND SOME CHANCE FOR PRECIPITATION BY LATE IN THE WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH TUESDAY)...
STRONG HIGH PRESSURE ALOFT OVER THE NORTHERN ROCKIES WILL SLOWLY
WEAKEN AND MOVE SOUTHEAST THROUGH TUESDAY. LOW PRESSURE WILL BEGIN
TO DEVELOP OVER THE EASTERN PACIFIC AND MOVE TOWARD THE COAST. AT
THE SURFACE...WEAK OFFSHORE FLOW WILL CONTINUE AT TIMES INTO
TUESDAY. MINOR DAY TO DAY CHANGES FOR TODAY AND MONDAY WITH WEAK
OFFSHORE FLOW AT TIMES...STRONGEST IN NORMALLY WIND PRONE AREAS
DURING THE MORNING HOURS. FOR MONDAY EVENING...THE NAM HINTS THAT
STRATUS MAY REDEVELOP OVER THE COASTAL WATERS AND EXTEND LOCALLY
INLAND IN THE FORM OF DENSE FOG...PERHAPS PULLING BACK OFF THE COAST
BY TUESDAY MORNING...NUDGED WESTWARD BY A COMBINATION OF WEAK
DRAINAGE AND WEAK OFFSHORE FLOW.
&&
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
THE TYPICAL NEARLY TOTAL LACK OF MODEL TO MODEL AND RUN TO RUN
CONSISTENCY CONTINUES AS HIGH PRESSURE BREAKS DOWN ALONG THE WEST
COAST. TODAY...THE FORECAST GENERALLY FOLLOWS THE GFS ENSEMBLE
MEAN...AT LEAST IN TERMS OF TIMING AND GENERAL STRENGTH OF SYSTEMS.
EVEN THIS IS A LOW CONFIDENCE FORECAST. THIS WOULD BRING ONE
WEAKENING SYSTEM INLAND LATE WEDNESDAY AND EARLY THURSDAY WITH
COOLING AND SMALL CHANCES OF PRECIPITATION...WITH A SECOND POSSIBLY
STRONGER SYSTEM FOR THE WEEKEND WITH ADDITIONAL COOLING AND GREATER
CHANCES FOR PRECIPITATION. ONE SHOULD NOT YET FOCUS ON THE DETAILS
AND SHOULD INSTEAD FOCUS MORE ON THE GENERAL TRENDS FOR THE LATTER
HALF OF THE WEEK...COOLER...MORE CLOUDS...AND SOME CHANCES FOR
PRECIPITATION.
&&
.AVIATION...
181000Z...MOSTLY CLEAR EXCEPT SOME HIGH CLOUDS TODAY...INCREASING
HIGH CLOUDS TONIGHT THROUGH MONDAY. SOME GUSTY NORTHEAST WINDS TO 25
KT INLAND VALLEYS THROUGH CANYONS AND PASSES AND OVER MOUNTAINS...
MAINLY AT ONT AND SOME WIND POSSIBLE AT SNA.
&&
.MARINE...
181000Z...WEST NORTHWEST SWELL NOT EXPECTED TO INCREASE MUCH MORE.
HIGH SURF POSSIBLE ALONG SAN DIEGO COUNTY COAST...MAINLY SOUTH.
LARGER WAVES MAY AFFECT ENTRANCES TO BAYS AND HARBORS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...WHITLOW
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSGX 180431
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST SAT JAN 17 2009
.SYNOPSIS...HIGH PRESSURE WILL WILL MAINTAIN MOSTLY CLEAR AND WARM
WEATHER THROUGH TUESDAY. A COUPLE OF UPPER LEVEL LOW PRESSURE
SYSTEMS WILL BRING MORE CLOUDS AND COOLING DURING THE SECOND HALF OF
NEXT WEEK WITH A SMALL CHANCE OF LIGHT SHOWERS WEDNESDAY INTO
THURSDAY AND AGAIN TOWARD NEXT WEEKEND.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-TUESDAY)...SKIES WERE CLEAR THIS EVENING. THE
00Z NKX SOUNDING WAS DRY WITH WEAK E TO NE WINDS IN THE LOW LEVELS
AND WLY WINDS ALOFT. OFFSHORE GRADIENTS WITH ABOUT -11 MB SAN-TPH.
HIGH PRESSURE ALOFT WILL MOVE SLOWLY E. SURFACE HIGH PRESSURE WILL
BRIEFLY STRENGTHEN OVER THE INTERIOR FOR A LITTLE STRONGER OFFSHORE
FLOW SUNDAY. WINDS COULD LOCALLY GET NEAR ADVISORY STRENGTH THROUGH
AND BELOW MOUNTAIN CANYONS AND PASSES...MAINLY BELOW THE CAJON PASS
AND IN THE SANTA ANA MOUNTAINS WITH GUSTS TO ABOUT 45 MPH.
HOWEVER...WINDS SHOULD NOT BE WIDESPREAD OR SUSTAINED ENOUGH FOR
WIND ADVISORIES. WEAKER OFFSHORE FLOW WILL CONTINUE THROUGH MONDAY.
CONTINUED MOSTLY CLEAR WITH WARM DAYS...ESPECIALLY W OF THE
MOUNTAINS SUNDAY AND MONDAY WITH MAX TEMPS 10 TO 15 DEGREES ABOVE
SEASONAL. A LITTLE COOLER TUESDAY AS THE UPPER HIGH SHIFTS E AND THE
OFFSHORE FLOW WEAKENS.
&&
.LONG TERM (WEDNESDAY-SATURDAY)...DETAILS REMAIN UNCERTAIN BUT A
TROUGH APPROACHING FROM THE NW SHOULD BRING MORE CLOUDS AND COOLING
WITH A SMALL CHANCE OF LIGHT PRECIP WEDNESDAY INTO THURSDAY MORNING.
DRY AND COOL NW FLOW THURSDAY AFTERNOON FOR DECREASING CLOUDS.
SLIGHTLY WARMER FRIDAY UNDER A SHORT WAVE RIDGE. ANOTHER TROUGH WILL
BRING A SLIGHT CHANCE OF PRECIP AGAIN TOWARD NEXT WEEKEND.
&&
.AVIATION...
180300Z...CLEAR THROUGH SUNDAY. LOCAL LOW LEVEL WIND SHEAR
POSSIBLE...ESPECIALLY BELOW MOUNTAIN PASSES AND CANYONS DUE TO GUSTY
OFFSHORE WINDS TO 25 KT AT TIMES.
&&
.MARINE...
LONG PERIOD WEST-NORTHWEST SWELL WILL INCREASE OVERNIGHT AND
CONTINUE THROUGH TUESDAY. SAN NICOLAS ISLAND ALREADY OVER 8 FT BY
02Z...SO INNER BUOYS SHOULD INCREASE TO PROJECTED 7 FT BY MORNING.
LOCALLY HIGHER SETS POSSIBLE ON EXPOSED...WEST FACING BEACHES. HIGH
SURF ADVISORY IS IN EFFECT.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY
COASTAL AREAS AND HIGH SURF ADVISORY FROM 4 AM SUNDAY TO 2 PM PST
MONDAY FOR ORANGE COUNTY COASTAL AREAS. SEE LAXCFWSGX.
&&
$$
PUBLIC...ATKIN
AVIATION/MARINE...JAD
000
FXUS66 KSGX 172133
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PST SAT JAN 17 2009
.SYNOPSIS...
HIGH PRESSURE ALOFT TO THE NORTH WILL MAINTAIN WARM DRY WEATHER
THROUGH MONDAY WITH MOSTLY WEAK OFFSHORE WINDS AT TIMES. AS THE HIGH
PRESSURE ALONG THE WEST COAST BREAKS DOWN AROUND THE MIDDLE OF NEXT
WEEK...ONSHORE FLOW WILL RETURN BRINGING COOLER WEATHER...SOME
INCREASE IN CLOUDS...AND A CHANCE OF PRECIPITATION INTO NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
HIGH PRESSURE AND OFFSHORE FLOW WILL CONTINUE AT LEAST THROUGH
MONDAY AS A HIGH AMPLITUDE UPPER HIGH CONTINUES ALONG THE NORTHWEST
COAST. DAYTIME TEMPERATURES WILL CONTINUE ABOVE NORMAL. OFFSHORE
PRESSURE GRADIENTS WILL BE THE MAIN CAUSE OF SOME OFFSHORE WINDS
THROUGH MONDAY. THOSE GRADIENTS TIGHTEN UP ON SUNDAY AND TOP WIND
SPEEDS WILL APPROACH ADVISORY CRITERIA...BUT NOT QUITE REACH IT
EXCEPT FOR POSSIBLY A FEW LOCAL GUSTS. OFFSHORE GRADIENTS ARE WEAKER
MONDAY. THE UPPER HIGH GRADUALLY MOVES EASTWARD ALLOWING A TROUGH TO
ADVANCE INTO THE WEST COAST TUESDAY AND WEDNESDAY. THIS TROUGH
APPEARS TO KILL ITSELF AGAINST OUR ROBUST WESTERN RIDGE...BUT IT MAY
DRAG JUST ENOUGH MOISTURE INTO THE REGION FOR SOME SHOWERS. THE EURO
MODEL HAS BEEN MORE CONSISTENT WITH THAT SLIGHTLY WET IDEA WHILE THE
GFS MODEL HAS BEEN WET AND DRY WITH THAT TROUGH. EITHER WAY THAT
TROUGH WILL WEAKEN THE RIDGE ENOUGH TO ALLOW THE NEXT SHORTWAVE
TROUGH TO HEAD INTO THE REGION TOWARD THE WEEKEND. ONCE AGAIN THE
MAIN EXTENDED MODELS DIFFER...THE EURO DRY AND THE GFS WET. THERE IS
JUST ENOUGH JUSTIFICATION TO INCLUDE SMALL CHANCES OF PRECIP IN THE
FORECAST FOR BOTH THE WEDNESDAY AND SATURDAY SYSTEMS. CONFIDENCE
REMAINS RATHER LOW IN THE TIMING AND PROBABILITY OF RAIN...BUT
TEMPERATURES WILL SURELY GET BACK TO NORMAL OR BELOW.
&&
172000Z...CLEAR THROUGH SUNDAY WITH OCCASIONAL GUSTY NORTHEAST WINDS
MAINLY BELOW PASSES AND CANYONS NEAR KONT...KSBD AND KRAL. HORTON
&&
.MARINE...
LONG PERIOD WEST NORTHWEST SWELL RATHER SMALL CURRENTLY BUT WILL
INCREASE LATER THIS AFTERNOON THROUGH SUNDAY WITH NOT MUCH CHANGE
MONDAY. THE SWELL IS EXPECTED TO INCREASE TO 4 TO 5 FEET INNER TO 7
TO 8 FEET OUTER BY SUNDAY. LARGER WAVES MAY AFFECT JETTIES AND
ENTRANCES TO BAYS AND HARBORS LATER TODAY THROUGH MONDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY FROM 4 AM SUNDAY TO 2 PM PST MONDAY FOR
ORANGE COUNTY COASTAL AREAS.
HIGH SURF ADVISORY UNTIL 2 PM PST MONDAY FOR SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...MM
AVIATION/MARINE...HORTON
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