000
FXUS65 KTWC 201635
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
935 AM MST TUE JAN 20 2009
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO PROVIDE SOUTHEAST ARIZONA
WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH MID WEEK EVEN AS SOME
CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM SYSTEM IS EXPECTED
TO BRING COOLER TEMPERATURES ALONG WITH VALLEY RAIN AND MOUNTAIN
SNOW THURSDAY INTO EARLY FRIDAY.
&&
.DISCUSSION...NO CHANGE TO ONGOING FORECAST AS SATELLITE AND MODEL
DATA SHOW EXTREMELY AMPLIFIED RIDGE PERSISTING OVER THE REGION INTO
WEDNESDAY. THERE HAS BEEN AN INCREASE IN HIGH CLOUDS AND PW VALUES
OVER THE LAST 12-24 HOURS...HOWEVER STILL LOOKING AT MOSTLY SUNNY
SKIES TODAY AND WELL ABOVE NORMAL TEMPERATURES. READINGS IN THE
TUCSON METRO AREA ARE EXPECTED TO TOP OUT IN THE UPPER 70S THIS
AFTERNOON...OR NEARLY 15 DEGREES ABOVE SEASONAL AVERAGES. NO
UPDATES.
&&
.AVIATION...THERE WILL BE A MIX OF CLEAR TO PARTLY CLOUDY SKIES OVER
THE NEXT 24 HOURS. ANY CLOUDS WILL REMAIN ABOVE 15KFT AGL. WINDS
WILL BE LIGHT AND DIURNALLY DRIVEN NEAR 10 KTS OR LESS THROUGH
TUESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.PREV DISCUSSION...JUST SOME TIMING ADJUSTMENTS...OTHERWISE SIMILAR
TO PREVIOUS FORECAST CYCLE. LARGE SCALE RIDGE STILL IN CONTROL OF
THE WEATHER ACROSS THE WEST AS THE PATTERN STARTS TO WEAKEN. BASE OF
THE RIDGE HAS SEVERAL WEAKNESSES IN IT WITH A SWATH OF MID AND HIGH
LEVEL MOISTURE IN A LONG FETCH FROM THE SOUTH PUSHING INTO THE
DESERT SOUTHWEST. EVEN WITH MORE CLOUD COVER...AFTERNOON HIGHS WILL
REMAIN WELL ABOVE SEASONAL AVERAGES THE NEXT COUPLE OF DAYS AS LOWER
LEVELS REMAIN ON THE DRY SIDE.
THE RIDGE BREAKS DOWN AND PHASES EASTWARD LATE WEDNESDAY...WITH A
NICE SYSTEM COMING IN OFF THE PACIFIC THURSDAY AND FRIDAY. INITIAL
UPSLOPE WILL HELP DRAW DEEPER MOISTURE INTO THE AREA AHEAD OF IT AND
PROVIDE PLENTY TO WORK WITH. LIGHT PRECIP WITH THE UPSLOPE LATE
WEDNESDAY NIGHT...THEN DYNAMICS AND A GOOD SOUTHERLY MOISTURE TAP
COME TOGETHER FOR A DECENT CHANCE OF SHOWERS BY LATE THURSDAY AND
THURSDAY NIGHT AS THE SHEARING SYSTEM IS DRAWN THROUGH IN ZONAL
CONTINENTAL FLOW. NOT TERRIBLY COLD...BUT IT SHOULD KNOCK
TEMPERATURES BACK BELOW CLIMO AND BRING HIGH ELEVATION SNOW. PRECIP
AND WATER EQUIVALENT AMOUNTS ARE STARTING TO SHAPE UP TO A DECENT
EVENT WITH VALLEY QPF IN THE 1/5 TO 1/2 INCH RANGE AND MOUNTAIN
VALUES OVER 1/2 INCH. WE SHOULD THEN BE OPEN FOR FURTHER ACTIVITY
OFF THE PACIFIC BY SUNDAY OR MONDAY WITH THE PATTERN CHANGE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 200906
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 AM MST TUE JAN 20 2009
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO PROVIDE SOUTHEAST ARIZONA
WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH MID WEEK EVEN AS SOME
CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM SYSTEM IS EXPECTED
TO BRING COOLER TEMPERATURES ALONG WITH VALLEY RAIN AND MOUNTAIN
SNOW THURSDAY INTO EARLY FRIDAY.
&&
.DISCUSSION...JUST SOME TIMING ADJUSTMENTS...OTHERWISE SIMILAR TO
PREVIOUS FORECAST CYCLE. LARGE SCALE RIDGE STILL IN CONTROL OF THE
WEATHER ACROSS THE WEST AS THE PATTERN STARTS TO WEAKEN. BASE OF THE
RIDGE HAS SEVERAL WEAKNESSES IN IT WITH A SWATH OF MID AND HIGH
LEVEL MOISTURE IN A LONG FETCH FROM THE SOUTH PUSHING INTO THE
DESERT SOUTHWEST. EVEN WITH MORE CLOUD COVER...AFTERNOON HIGHS WILL
REMAIN WELL ABOVE SEASONAL AVERAGES THE NEXT COUPLE OF DAYS AS LOWER
LEVELS REMAIN ON THE DRY SIDE.
THE RIDGE BREAKS DOWN AND PHASES EASTWARD LATE WEDNESDAY...WITH A
NICE SYSTEM COMING IN OFF THE PACIFIC THURSDAY AND FRIDAY. INITIAL
UPSLOPE WILL HELP DRAW DEEPER MOISTURE INTO THE AREA AHEAD OF IT AND
PROVIDE PLENTY TO WORK WITH. LIGHT PRECIP WITH THE UPSLOPE LATE
WEDNESDAY NIGHT...THEN DYNAMICS AND A GOOD SOUTHERLY MOISTURE TAP
COME TOGETHER FOR A DECENT CHANCE OF SHOWERS BY LATE THURSDAY AND
THURSDAY NIGHT AS THE SHEARING SYSTEM IS DRAWN THROUGH IN ZONAL
CONTINENTAL FLOW. NOT TERRIBLY COLD...BUT IT SHOULD KNOCK
TEMPERATURES BACK BELOW CLIMO AND BRING HIGH ELEVATION SNOW. PRECIP
AND WATER EQUIVALENT AMOUNTS ARE STARTING TO SHAPE UP TO A DECENT
EVENT WITH VALLEY QPF IN THE 1/5 TO 1/2 INCH RANGE AND MOUNTAIN
VALUES OVER 1/2 INCH. WE SHOULD THEN BE OPEN FOR FURTHER ACTIVITY
OFF THE PACIFIC BY SUNDAY OR MONDAY WITH THE PATTERN CHANGE.
&&
.AVIATION...THERE WILL BE A MIX OF CLEAR TO PARTLY CLOUDY SKIES OVER
THE NEXT 24 HOURS. ANY CLOUDS WILL REMAIN ABOVE 15KFT AGL. WINDS
WILL BE LIGHT AND DIURNALLY DRIVEN NEAR 10 KTS OR LESS THROUGH
TUESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 200415
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
915 PM MST MON JAN 19 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY EVEN
AS MID AND HIGH CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM
SYSTEM IS EXPECTED TO BRING COOLER TEMPERATURES ALONG WITH VALLEY
RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS BY WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.DISCUSSION...WHAT CAN I SAY...ANOTHER GORGEOUS DAY ACROSS SOUTHEAST
ARIZONA WITH HIGH TEMPERATURES IN THE 70S TO LOWER 80S. EARLIER THIS
AFTERNOON A BATCH OF MID-LEVEL CLOUDS WAS MOVING NORTH FROM SONORA
MEXICO AND IT LOOKED LIKE MOST AREAS WOULD HAVE A PARTLY CLOUDY
NIGHT. HOWEVER DURING THE LATE AFTERNOON/EARLY EVENING HOURS THESE
CLOUDS STARTED BREAKING UP. THIS ALONG WITH 18Z NAM GUIDANCE I
UPDATED THE TEXT/GRID BASED FORECASTS AND KEPT PARTLY CLOUDY
CONDITIONS SOUTH OF TUCSON WITH MOSTLY CLEAR ELSEWHERE. WITH LESS
CLOUD COVER...OVERNIGHT LOWS WILL BE COOLER THAN THIS MORNING. CHECK
PREVIOUS DISCUSSION SECTION FOR LATEST ON NEXT STORM TO IMPACT THE
AREA.
&&
.AVIATION...THERE WILL BE A MIX OF CLEAR TO PARTLY CLOUDY SKIES OVER
THE NEXT 24 HOURS. ANY CLOUDS WILL REMAIN ABOVE 15KFT AGL. WINDS
WILL BE LIGHT AND DIURNALLY DRIVEN NEAR 10 KTS OR LESS THROUGH
TUESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.PREVIOUS DISCUSSION...MORE ESTABLISHED SOUTHWESTERLY FLOW ALOFT
WILL ESTABLISH ITSELF BY WEDNESDAY AS A LARGE TROUGH NOW ACROSS THE
EASTERN PACIFIC PUSHES EAST INTO THE WESTERN US. THERE IS
CONSIDERABLE MOISTURE PER LATEST SATELLITE IMAGERY CURRENTLY LOCATED
NEAR AND WEST OF SOUTHERN BAJA IN ADDITION TO A LARGE PLUME
EXTENDING WELL NORTH OUT AHEAD OF THE TROUGH ITSELF. AS THE SYSTEM
APPROACHES WEDNESDAY WE WILL REMAIN QUITE MILD EVEN WITH THE
ADDITIONAL CLOUDINESS AS THE ATMOSPHERE MOISTENS FROM THE TOP DOWN
WITH MOISTURE ADVECTING NORTHWARD. AS THE LOWER LEVELS CONTINUE TO
MOISTEN THE CHANCE OF SHOWERS WILL INCREASE WEDNESDAY NIGHT. FOR
THURSDAY INTO THURSDAY NIGHT WITH THE MAIN SYSTEM ITSELF...THERE
REMAIN SOME MINOR DIFFERENCES IN THE EVOLUTION AND TIMING OF THE
TROUGH AS IT PUSHES THROUGH. THE ECMWF HAS BEEN THE MOST CONSISTENT
OVERALL THE LAST FEW DAYS AND WILL CONTINUE TO LEAN THAT DIRECTION
WITH THE FORECAST A BIT ON THE WETTER SIDE COMPARED TO THE LATEST
ECMWF. WITH THAT SAID HAVE INCREASED THE POPS INTO THE CHANCE
CATEGORY WEDNESDAY NIGHT WITH CHANCE TO LOW END LIKELY POPS DURING
THE DAY THURSDAY. AS THE TROUGH PUSHES EAST ACROSS THE AREA THURSDAY
NIGHT INTO FRIDAY RAIN CHANCES WILL DIMINISH FROM WEST TO EAST. THIS
WILL BE A WARM SYSTEM AS DAYTIME TEMPERATURES ONLY COOL TO NEAR
NORMAL VALUES FOR THIS TIME OF YEAR. SNOW LEVELS WILL REMAIN NEAR
THE HIGHEST MOUNTAINTOPS WITH QPF VALUES GENERALLY LESS THAN A
QUARTER OF AN INCH IN VALLEY LOCATIONS AND UP TO A HALF INCH IN THE
MOUNTAINS.
ONCE THIS SYSTEM PULLS OUT A BRIEF PERIOD OF QUIET WEATHER IS
EXPECTED BEFORE THE NEXT TROUGH APPROACHES SUNDAY AND MONDAY FROM
THE NORTHWEST. WILL KEEP MOST OF THE AREA DRY DURING THIS PERIOD
WITH THE EXCEPTION OF THE WHITE MOUNTAINS WHERE WILL DEPICT SLIGHT
CHANCE OF SHOWERS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 192056
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
156 PM MST MON JAN 19 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY EVEN
AS MID AND HIGH CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM
SYSTEM IS EXPECTED TO BRING COOLER TEMPERATURES ALONG WITH VALLEY
RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS BY WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
&&
.DISCUSSION...LARGE UPPER LEVEL RIDGE ACROSS THE NORTHERN ROCKIES
CONTINUES TO RESULT IN VERY MILD TEMPERATURES FOR JANUARY WITH HIGHS
NEAR 80F IN THE DESERTS. THIS RIDGE WILL START TO WEAKEN TUESDAY
WITH MID AND HIGH LEVEL MOISTURE INFILTRATING INTO THE AREA FROM THE
SOUTH AND CONTINUED WELL ABOVE NORMAL TEMPERATURES.
MORE ESTABLISHED SOUTHWESTERLY FLOW ALOFT WILL ESTABLISH ITSELF BY
WEDNESDAY AS A LARGE TROUGH NOW ACROSS THE EASTERN PACIFIC PUSHES
EAST INTO THE WESTERN US. THERE IS CONSIDERABLE MOISTURE PER LATEST
SATELLITE IMAGERY CURRENTLY LOCATED NEAR AND WEST OF SOUTHERN BAJA
IN ADDITION TO A LARGE PLUME EXTENDING WELL NORTH OUT AHEAD OF THE
TROUGH ITSELF. AS THE SYSTEM APPROACHES WEDNESDAY WE WILL REMAIN
QUITE MILD EVEN WITH THE ADDITIONAL CLOUDINESS AS THE ATMOSPHERE
MOISTENS FROM THE TOP DOWN WITH MOISTURE ADVECTING NORTHWARD. AS THE
LOWER LEVELS CONTINUE TO MOISTEN THE CHANCE OF SHOWERS WILL INCREASE
WEDNESDAY NIGHT. FOR THURSDAY INTO THURSDAY NIGHT WITH THE MAIN
SYSTEM ITSELF...THERE REMAIN SOME MINOR DIFFERENCES IN THE EVOLUTION
AND TIMING OF THE TROUGH AS IT PUSHES THROUGH. THE ECMWF HAS BEEN
THE MOST CONSISTENT OVERALL THE LAST FEW DAYS AND WILL CONTINUE TO
LEAN THAT DIRECTION WITH THE FORECAST A BIT ON THE WETTER SIDE
COMPARED TO THE LATEST ECMWF. WITH THAT SAID HAVE INCREASED THE POPS
INTO THE CHANCE CATEGORY WEDNESDAY NIGHT WITH CHANCE TO LOW END
LIKELY POPS DURING THE DAY THURSDAY. AS THE TROUGH PUSHES EAST
ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY RAIN CHANCES WILL
DIMINISH FROM WEST TO EAST. THIS WILL BE A WARM SYSTEM AS DAYTIME
TEMPERATURES ONLY COOL TO NEAR NORMAL VALUES FOR THIS TIME OF YEAR.
SNOW LEVELS WILL REMAIN NEAR THE HIGHEST MOUNTAINTOPS WITH QPF
VALUES GENERALLY LESS THAN A QUARTER OF AN INCH IN VALLEY LOCATIONS
AND UP TO A HALF INCH IN THE MOUNTAINS.
ONCE THIS SYSTEM PULLS OUT A BRIEF PERIOD OF QUIET WEATHER IS
EXPECTED BEFORE THE NEXT TROUGH APPROACHES SUNDAY AND MONDAY FROM
THE NORTHWEST. WILL KEEP MOST OF THE AREA DRY DURING THIS PERIOD
WITH THE EXCEPTION OF THE WHITE MOUNTAINS WHERE WILL DEPICT SLIGHT
CHANCE OF SHOWERS.
&&
.AVIATION...PARTLY CLOUDY SKIES ARE EXPECTED THROUGH TUESDAY WITH
CLOUD LEVELS EXPECTED TO REMAIN ABOVE 15K FT AGL. WINDS WILL BE
LIGHT AND DIURNALLY DRIVEN NEAR 10 KTS OR LESS THROUGH TUESDAY.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 191600
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
900 AM MST MON JAN 19 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY EVEN
AS MID AND HIGH CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM
SYSTEM IS EXPECTED TO BRING COOLER TEMPERATURES ALONG WITH VALLEY
RAIN AND MOUNTAIN SNOW BY THURSDAY AND THURSDAY NIGHT.
&&
.DISCUSSION...LARGE UPPER LEVEL RIDGE ACROSS THE NORTHERN ROCKIES
WILL REMAIN THE DOMINANT FACTOR IN OUR WEATHER THROUGH TUESDAY. WE
WILL CONTINUE TO SEE SOME MAINLY CIRRUS CLOUDS THIS AFTERNOON WITH
CONTINUED VERY WARM TEMPERATURES FOR JANUARY AS HIGHS APPROACH OR
POSSIBLY HIT 80F IN SOME OF THE DESERTS INCLUDING TUCSON. THIS RIDGE
WILL START TO WEAKEN TUESDAY WITH ADDITIONAL MID AND HIGH LEVEL
MOISTURE INFILTRATING INTO THE AREA FROM THE SOUTH AND CONTINUED
WELL ABOVE NORMAL TEMPERATURES. WILL MAKE NO CHANGES TO THE FORECAST
THIS MORNING. PLEASE SEE PREVIOUS DISCUSSION BELOW FOR MORE
INFORMATION ON SYSTEM LATER THIS WEEK.
&&
.AVIATION...LAYERED CLOUDS ABOVE 15K FEET AGL ARE EXPECTED THROUGH
TUESDAY. WINDS WILL BE LIGHT AND DIURNALLY DRIVEN NEAR 10 KTS OR
LESS THROUGH MONDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.PREV DISCUSSION...THE RIDGE BREAKS DOWN AND PHASES EASTWARD
WEDNESDAY...WITH A NICE SYSTEM COMING IN OFF THE PACIFIC THURSDAY.
INITIAL UPSLOPE WILL HELP DRAW DEEPER MOISTURE INTO THE AREA AHEAD
OF IT AND PROVIDE PLENTY TO WORK WITH. LIGHT PRECIP WITH THE UPSLOPE
WEDNESDAY NIGHT...THEN DYNAMICS AND MOISTURE COME TOGETHER FOR A
DECENT CHANCE OF SHOWERS THURSDAY AND THURSDAY NIGHT AS THE SHEARING
SYSTEM IS DRAWN THROUGH IN ZONAL CONTINENTAL FLOW. NOT TERRIBLY
COLD...BUT IT SHOULD KNOCK TEMPERATURES BACK BELOW CLIMO AND BRING
HIGH ELEVATION SNOW. PRECIP AND WATER EQUIVALENT AMOUNTS ARE
STARTING TO SHAPE UP TO A DECENT EVENT WITH VALLEY QPF IN THE 1/4
INCH OR BETTER RANGE AND MOUNTAIN VALUES OVER 1/2 INCH. WE SHOULD
THEN BE OPEN FOR FURTHER ACTIVITY OFF THE PACIFIC BY SUNDAY OR
MONDAY WITH THE PATTERN CHANGE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 190921
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
215 AM MST MON JAN 19 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY EVEN
AS MID AND HIGH CLOUDS SPREAD IN FROM THE SOUTH. A PACIFIC STORM
SYSTEM IS EXPECTED TO BRING COOLER TEMPERATURES ALONG WITH VALLEY
RAIN AND MOUNTAIN SNOW BY THURSDAY AND THURSDAY NIGHT.
&&
.DISCUSSION...LARGE SCALE RIDGE STILL IN CONTROL OF THE WEATHER
ACROSS THE WEST AS THE PATTERN AMPLIFIES. BASE OF THE RIDGE HAS
SEVERAL WEAKNESSES IN IT WITH A SWATH OF MID AND HIGH LEVEL MOISTURE
IN A LONG FETCH FROM THE SOUTH PUSHING INTO THE DESERT SOUTHWEST.
EVEN WITH MORE CLOUD COVER...AFTERNOON HIGHS WILL REMAIN WELL ABOVE
SEASONAL AVERAGES THE NEXT COUPLE OF DAYS AS LOWER LEVELS REMAIN ON
THE DRY SIDE.
THE RIDGE BREAKS DOWN AND PHASES EASTWARD WEDNESDAY...WITH A NICE
SYSTEM COMING IN OFF THE PACIFIC THURSDAY. INITIAL UPSLOPE WILL HELP
DRAW DEEPER MOISTURE INTO THE AREA AHEAD OF IT AND PROVIDE PLENTY TO
WORK WITH. LIGHT PRECIP WITH THE UPSLOPE WEDNESDAY NIGHT...THEN
DYNAMICS AND MOISTURE COME TOGETHER FOR A DECENT CHANCE OF SHOWERS
THURSDAY AND THURSDAY NIGHT AS THE SHEARING SYSTEM IS DRAWN THROUGH
IN ZONAL CONTINENTAL FLOW. NOT TERRIBLY COLD...BUT IT SHOULD KNOCK
TEMPERATURES BACK BELOW CLIMO AND BRING HIGH ELEVATION SNOW. PRECIP
AND WATER EQUIVALENT AMOUNTS ARE STARTING TO SHAPE UP TO A DECENT
EVENT WITH VALLEY QPF IN THE 1/4 INCH OR BETTER RANGE AND MOUNTAIN
VALUES OVER 1/2 INCH. WE SHOULD THEN BE OPEN FOR FURTHER ACTIVITY
OFF THE PACIFIC BY SUNDAY OR MONDAY WITH THE PATTERN CHANGE.
&&
.AVIATION...LAYERED CLOUDS ABOVE 15K FEET AGL WILL CONTINUE TO
SPREAD IN FROM THE SOUTH TODAY. WINDS WILL BE LIGHT AND DIURNALLY
DRIVEN NEAR 10 KTS OR LESS THROUGH MONDAY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 190412
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
912 PM MST SUN JAN 18 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...ALONG WITH COOLER TEMPERATURES AND A CHANCE OF VALLEY
RAIN AND MOUNTAIN SNOW SHOWERS ON THURSDAY.
&&
.DISCUSSION...JUST ANOTHER SPECTACULAR DAY ACROSS SOUTHERN ARIZONA
WITH DAYTIME HIGHS IN THE 70S TO LOWER 80S...THE FIRST 80S OF 2009.
SATELLITE IMAGERY THIS EVENING SHOWED EXTENSIVE MID-HI LEVEL
CLOUDINESS APPROACHING FROM THE SOUTHWEST. BASED ON 00Z MOS GUIDANCE
AND CLOUD TRENDS...WILL MAKE SOME CHANGES TO TEXT/GRID BASED
FORECASTS BY RAISING OVERNIGHT LOWS SEVERAL DEGREES AND ALSO
INCREASE CLOUD COVER FROM MOSTLY CLEAR TO PARTLY CLOUDY. SEE
PREVIOUS DISCUSSION SECTION BELOW FOR REST OF FORECAST THINKING.
&&
.AVIATION...LAYERED CLOUDS ABOVE 15K FEET AGL WILL CONTINUE TO
SPREAD IN FROM THE SOUTH OVER THE NEXT 24 HOURS. WINDS WILL BE LIGHT
AND DIURNALLY DRIVEN AT 10 KTS OR LESS THROUGH MONDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.PREVIOUS DISCUSSION...AS SUSPECTED YESTERDAY GFS HAS COME INTO
BETTER AGREEMENT WITH THE FAR MORE CONSISTENT ECMWF REGARDING THE
STRONG PACIFIC TROUGH CURRENTLY NEAR 40N/140W. CONFIDENCE IS
INCREASING THAT A SIGNIFICANT CHANGE IN ARIZONA WEATHER WILL OCCUR
THIS WEEK...ESPECIALLY CONSIDERING THE SUNNY UNSEASONABLE WARMTH WE
ARE ENJOYING NOW. THAT BEING SAID...THERE STILL IS...AND WILL
CONTINUE TO BE...TRACK AND TIMING ISSUES WITH THE APPROACHING STORM
SYSTEM. WHILE 12Z GFS AT LEAST HAS A CLOSED LOW AFFECTING ARIZONA
AROUND THURSDAY...IT STILL APPEARS TO BE A LITTLE TOO FAST. POP AND
WEATHER GRIDS IN THIS PACKAGE FOLLOW THE SLOWER 00Z/12Z
ECMWF...ALTHOUGH EVEN THIS MODEL IS NOT TERRIBLY CONSISTENT ON THE
EXACT TRACK OF THE UPPER LOW. IRREGARDLESS OF THE DETAILS...IT
APPEARS PROBABLE THAT A SIGNIFICANT STORM SYSTEM WITH DECENT
DYNAMICS WILL INTERACT WITH PLENTIFUL MOISTURE AND AFFECT ARIZONA
LATE WEDNESDAY THROUGH EARLY FRIDAY. AS RIDGE OF HIGH PRESSURE
PHASES EAST INTO THE PLAINS...SHOULD SEE A RAPID INCREASE IN CLOUDS
ON WEDNESDAY AS SOUTHWESTERLY FLOW DEVELOPS. SATURATION WILL OCCUR
FROM THE TOP DOWN AGAIN...WITH LIKELY VIRGA OR SPRINKLES DEVELOPING
DURING WEDNESDAY. UNDERCUT TEMPS ON WEDNESDAY FROM WHAT
MEX/THICKNESS ARGUMENTS WOULD SUGGEST WITH THE CLOUDS. MAIN EVENT IS
EXPECTED TO BE THURSDAY AND THURSDAY NIGHT...WITH OUR POPS RAISED
FURTHER INTO THE 40-50% RANGE...WITH LIKELY POPS MENTIONED IN THE
WHITE MOUNTAINS. CHOPPED DOWN TEMPS WITH THE CLOUDS AND PRECIP
THURSDAY. FEEL POPS WILL HAVE TO RAISED FURTHER WITH SUBSEQUENT
SHIFTS...BUT STILL AWAITING TRACK AND TIMING ISSUES...AND STILL HAVE
PLENTY OF TIME WITH A 4-DAY FORECAST. SNOW AMOUNTS IN THE MOUNTAINS
WILL BE DICTATED BY SNOW LEVELS AND THE EVENTUAL TRACK OF THE UPPER
LOW...TO BE DETERMINED IN THE COMING DAYS. A SIGNIFICANT PRECIP
EVENT IS STILL POSSIBLE...AND IF MODEL CONSISTENCY HOLDS...WILL
LIKELY HAVE TO BEGIN A HAZARDOUS WEATHER OUTLOOK ADDRESSING THE
POTENTIAL SOON.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 182050
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
150 PM MST SUN JAN 18 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...ALONG WITH COOLER TEMPERATURES AND A CHANCE OF VALLEY
RAIN AND MOUNTAIN SNOW SHOWERS ON THURSDAY.
&&
.DISCUSSION...ANOTHER UNSEASONABLY WARM AFTERNOON ACROSS SOUTHEAST
ARIZONA. STRONG HIGH PRESSURE RIDGE ALOFT...ALONG WITH COMPRESSIONAL
HEATING ASSOCIATED WITH DOWNSLOPE EASTERLY SURFACE FLOW...WILL
ENSURE WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE MONDAY AND
TUESDAY AFTERNOONS. STOPPED A LITTLE SHORT OF THE WARMEST NAM MOS
GUIDANCE...GIVEN CIRRUS SLOWLY INCREASING THE NEXT FEW DAYS. IR
SATELLITE IMAGERY SHOWS WIDESPREAD SUBTROPICAL MOISTURE SOUTH OF
ARIZONA...AND THIS IS EXPECTED TO BE DRAWN SLOWLY NORTHWARD AS
PACIFIC TROUGH APPROACHES. STILL...WOULD NOT BE SURPRISED TO SEE A
FEW 80 DEGREE READINGS POP UP BETWEEN THE CIRRUS.
AS SUSPECTED YESTERDAY...GFS HAS COME INTO BETTER AGREEMENT WITH THE
FAR MORE CONSISTENT ECMWF REGARDING THE STRONG PACIFIC TROUGH
CURRENTLY NEAR 40N/140W. CONFIDENCE IS INCREASING THAT A SIGNIFICANT
CHANGE IN ARIZONA WEATHER WILL OCCUR THIS WEEK...ESPECIALLY
CONSIDERING THE SUNNY UNSEASONABLE WARMTH WE ARE ENJOYING NOW. THAT
BEING SAID...THERE STILL IS...AND WILL CONTINUE TO BE...TRACK AND
TIMING ISSUES WITH THE APPROACHING STORM SYSTEM. WHILE 12Z GFS AT
LEAST HAS A CLOSED LOW AFFECTING ARIZONA AROUND THURSDAY...IT STILL
APPEARS TO BE A LITTLE TOO FAST. POP AND WEATHER GRIDS IN THIS
PACKAGE FOLLOW THE SLOWER 00Z/12Z ECMWF...ALTHOUGH EVEN THIS MODEL
IS NOT TERRIBLY CONSISTENT ON THE EXACT TRACK OF THE UPPER LOW.
IRREGARDLESS OF THE DETAILS...IT APPEARS PROBABLE THAT A SIGNIFICANT
STORM SYSTEM WITH DECENT DYNAMICS WILL INTERACT WITH PLENTIFUL
MOISTURE AND AFFECT ARIZONA LATE WEDNESDAY THROUGH EARLY FRIDAY. AS
RIDGE OF HIGH PRESSURE PHASES EAST INTO THE PLAINS...SHOULD SEE A
RAPID INCREASE IN CLOUDS ON WEDNESDAY AS SOUTHWESTERLY FLOW
DEVELOPS. SATURATION WILL OCCUR FROM THE TOP DOWN AGAIN...WITH
LIKELY VIRGA OR SPRINKLES DEVELOPING DURING WEDNESDAY. UNDERCUT
TEMPS ON WEDNESDAY FROM WHAT MEX/THICKNESS ARGUMENTS WOULD SUGGEST
WITH THE CLOUDS. MAIN EVENT IS EXPECTED TO BE THURSDAY AND THURSDAY
NIGHT...WITH OUR POPS RAISED FURTHER INTO THE 40-50% RANGE...WITH
LIKELY POPS MENTIONED IN THE WHITE MOUNTAINS. CHOPPED DOWN TEMPS
WITH THE CLOUDS AND PRECIP THURSDAY. FEEL POPS WILL HAVE TO RAISED
FURTHER WITH SUBSEQUENT SHIFTS...BUT STILL AWAITING TRACK AND TIMING
ISSUES...AND STILL HAVE PLENTY OF TIME WITH A 4-DAY FORECAST. SNOW
AMOUNTS IN THE MOUNTAINS WILL BE DICTATED BY SNOW LEVELS AND THE
EVENTUAL TRACK OF THE UPPER LOW...TO BE DETERMINED IN THE COMING
DAYS. A SIGNIFICANT PRECIP EVENT IS STILL POSSIBLE...AND IF MODEL
CONSISTENCY HOLDS...WILL LIKELY HAVE TO BEGIN A HAZARDOUS WEATHER
OUTLOOK ADDRESSING THE POTENTIAL SOON.
&&
.AVIATION...SCATTERED CIRRUS NEAR 25K FEET AGL EXPECTED THROUGH
MONDAY...OTHERWISE MOSTLY CLEAR SKIES. WINDS LIGHT AND DIURNALLY
DRIVEN AT 10 KTS OR LESS THROUGH MONDAY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
TURNER
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 181614
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
915 AM MST SUN JAN 18 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...ALONG WITH COOLER TEMPERATURES AND A CHANCE OF VALLEY
RAIN AND MOUNTAIN SNOW SHOWERS BY WEDNESDAY NIGHT AND THURSDAY.
&&
.DISCUSSION...A RIDGE OF HIGH PRESSURE ALOFT WILL STILL INFLUENCE
OUR WEATHER ACROSS SOUTHEAST ARIZONA TODAY. AS A RESULT...ANOTHER
DAY OF WELL ABOVE NORMAL HIGH TEMPERATURES CAN BE ANTICIPATED. THE
ONLY DIFFERENCE WILL BE SOME MORE HIGH CLOUDS PASSING THROUGH THE
AREA COURTESY OF A WEAK UPPER LOW SPINNING OFF THE BAJA COAST.
CURRENT FORECAST LOOKED ON TRACK...SO NO UPDATES NEEDED THIS
MORNING. PLEASE REFER TO THE PREVIOUS DISCUSSION BELOW FOR MORE
DETAILS.
&&
.AVIATION...INCREASING CIRRUS CLOUDS...ABOVE 20KFT...FROM THE SOUTH
ON TODAY. WINDS BECOMING EAST AT 5-15 KTS AT TAF SITES AFTER 18Z
TODAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.PREV DISCUSSION...LARGE SCALE RIDGE ALONG THE WEST COAST INTO
WESTERN STATES. LOOSING SOME FOCUS WITH PLENTY OF WEAKNESSES IN THE
FLOW ACCENTUATING PATCHES OF MID TO HIGH CLOUD AT TIMES. STRONG
SWATH OF MOISTURE NEAR AND SOUTHWEST THE BAJA PENINSULA. AS THE
RIDGE BREAKS DOWN AND PHASES EASTWARD...A TROUGH WILL PUSH INTO THE
COAST FROM THE PACIFIC AND DRAW THIS MOISTURE NORTHWARD INTO ARIZONA
BY WEDNESDAY. INITIALLY PLENTY OF CLOUD COVER WITH LIGHT SHOWERS AND
VIRGA ON WEDNESDAY BEFORE THE MAIN LOW PUSHES IN AND ACCENTUATES THE
COVERAGE AND INTENSITY OF SHOWER ACTIVITY BY THURSDAY. GFS MUCH
FURTHER NORTH THAN EUROPEAN. MIGHT SPLIT THE DIFFERENCE IN
TRAJECTORY FOR NOW...BUT GFS IS ALMOST CERTAINLY UNDERDOING THE
AVAILABLE MOISTURE FOR THIS SYSTEM. PROBABLY NOT THAT COLD OF A
SYSTEM...BUT TEMPERATURES WILL BE PUSHED BACK DOWN TO CLIMO...MAYBE
A LITTLE LOWER...WITH SNOW POSSIBLE ON HIGHER MOUNTAIN ELEVATIONS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 180937
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST SUN JAN 18 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...ALONG WITH COOLER TEMPERATURES AND A CHANCE OF VALLEY
RAIN AND MOUNTAIN SNOW SHOWERS BY WEDNESDAY NIGHT AND THURSDAY.
&&
.DISCUSSION...LARGE SCALE RIDGE ALONG THE WEST COAST INTO WESTERN
STATES. LOOSING SOME FOCUS WITH PLENTY OF WEAKNESSES IN THE FLOW
ACCENTUATING PATCHES OF MID TO HIGH CLOUD AT TIMES. STRONG SWATH OF
MOISTURE NEAR AND SOUTHWEST THE BAJA PENINSULA. AS THE RIDGE BREAKS
DOWN AND PHASES EASTWARD...A TROUGH WILL PUSH INTO THE COAST FROM
THE PACIFIC AND DRAW THIS MOISTURE NORTHWARD INTO ARIZONA BY
WEDNESDAY. INITIALLY PLENTY OF CLOUD COVER WITH LIGHT SHOWERS AND
VIRGA ON WEDNESDAY BEFORE THE MAIN LOW PUSHES IN AND ACCENTUATES THE
COVERAGE AND INTENSITY OF SHOWER ACTIVITY BY THURSDAY. GFS MUCH
FURTHER NORTH THAN EUROPEAN. MIGHT SPLIT THE DIFFERENCE IN
TRAJECTORY FOR NOW...BUT GFS IS ALMOST CERTAINLY UNDERDOING THE
AVAILABLE MOISTURE FOR THIS SYSTEM. PROBABLY NOT THAT COLD OF A
SYSTEM...BUT TEMPERATURES WILL BE PUSHED BACK DOWN TO CLIMO...MAYBE
A LITTLE LOWER...WITH SNOW POSSIBLE ON HIGHER MOUNTAIN ELEVATIONS.
&&
.AVIATION...INCREASING CIRRUS CLOUDS...ABOVE 20KFT...FROM THE SOUTH
ON TODAY. WINDS LIGHT AND DIURNALLY DRIVEN THROUGH 12Z...BECOMING
EAST AT 5-15 KTS AT TAF SITES AFTER 18Z SUNDAY. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 180421
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
920 PM MST SAT JAN 17 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...FOLLOWED BY A CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.DISCUSSION...BEAUTIFUL JANUARY DAY ACROSS THE REGION WITH HIGHS
8-12 DEGREES ABOVE NORMAL. UPPER AIR PLOTS THIS EVENING PLACED
CENTER OF HIGH PRESSURE OFF WASHINGTON COAST WITH WEAK TROFINESS
OVER THE DESERT SOUTHWEST. SATELLITE IMAGERY SHOWED AN IMPRESSIVE
BATCH OF MOISTURE OFF BAJA COAST ASSOCIATED WITH AN UPPER LOW AROUND
19N/124W. LEADING EDGE OF THIS MID-HI LEVEL MOISTURE WILL BE NEAR
THE INTERNATIONAL BORDER SUNDAY MORNING AND SLOWLY DRIFTING NORTH
ACROSS THE AREA SUNDAY FOR A MOSTLY TO PARTLY SUNNY DAY. HIGH
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. SEE PREVIOUS DISCUSSION
BELOW FOR EXTENDED PORTION OF THE FORECAST.
&&
.AVIATION...A CLEAR SKY OVERNIGHT WILL GIVE WAY TO INCREASING CIRRUS
CLOUDS...ABOVE 20KFT...FROM THE SOUTH ON SUNDAY. WINDS LIGHT AND
DIURNALLY DRIVEN THROUGH 12Z SUNDAY...BECOMING EAST AT 5-15 KTS AT
ALL TAF SITES AFTER 18Z SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.PREVIOUS DISCUSSION...THE EXTENDED PORTION OF THE FORECAST IS FAR
MORE CHALLENGING...AS WE CONTINUE TO WAIT FOR MODEL CONSISTENCY ON
THE EXPECTED PATTERN CHANGE NEXT WEEK. IN A NUTSHELL...THE AFTERNOON
FORECAST PACKAGE IS A BLEND OF 12Z ECMWF AND THE INHERITED
FORECAST...AND LARGELY IGNORES THE 12Z GFS. 12Z MEX GUIDANCE ARGUES
FOR NO MENTIONABLE POPS THROUGH NEXT WEEK...AND IT APPEARS THAT THE
DRY BIAS THAT MEX HAS SHOWN BEFORE THIS WINTER IS AT PLAY AGAIN. FOR
SEVERAL DAYS NOW...THE ECMWF HAS SHOWN SOME CONSISTENCY SHOWING A
CLOSED LOW APPROACHING SOUTHERN CALIFORNIA ON WEDNESDAY. GFS AND
ECMWF DO AGREE THAT CLOUDS WILL INCREASE IN SOUTHWESTERLY FLOW
ACROSS SOUTHEAST ARIZONA ON WEDNESDAY...AND THIS TREND WAS RETAINED
IN THE SKY GRIDS. BUT THATS WHERE THE SIMILARITY ENDS...WITH 12Z
ECMWF SHOWING A RATHER STRONG CLOSED LOW ENTERING WESTERN ARIZONA
THURSDAY MORNING...AND CROSSING THE CWA THURSDAY. ECMWF SUGGESTS
WIDESPREAD PRECIP AND MUCH COOLER TEMPERATURES THURSDAY...WHEREAS
GFS WOULD SUGGEST LOWER 70S AND DRY WEATHER. HISTORICALLY...ECMWF
HAS SHOWN BETTER SKILL WITH HANDLING PATTERN CHANGES...AND AS STATED
PREVIOUSLY ITS WET SOLUTION IS SHOWING SOME RECURRENCE IN THE MODEL
RUNS. POPS WERE INCREASED IN THE WEDNESDAY NIGHT THROUGH THURSDAY
TIME FRAME...HIGHEST ON THURSDAY WITH 30-40% POPS AND 50% IN THE
MOUNTAINS...WITH SNOW LEVELS MUCH LOWER THAN GFS WOULD SUGGEST.
AGAIN...THIS FORECAST IS BASED ON 12Z ECMWF AND THE INHERITED POP
GRIDS...AND IS NOT SUPPORTED BY 12Z GFS/MEX GUIDANCE. THE MODELS
WILL COME TO A CONSENSUS SOON...AND THE HUNCH IS GFS WILL FALL IN
LINE WITH THE ECMWF. A SIGNIFICANT PRECIP EVENT IS POSSIBLE
WEDNESDAY AND THURSDAY...BUT HARD TO SAY MUCH UNTIL GFS AGREES.
THANKFULLY...WE`RE STILL TALKING ABOUT A 4-5 DAY FORECAST AND THERE
IS PLENTY OF TIME TO ADJUST POPS UP OR DOWN.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KTWC 172140
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST SAT JAN 17 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE SOUTHEAST
ARIZONA WITH DRY AND UNSEASONABLY WARM WEATHER THROUGH TUESDAY. A
PACIFIC STORM SYSTEM IS EXPECTED TO BRING INCREASING CLOUDS ON
WEDNESDAY...FOLLOWED BY A CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.DISCUSSION...JUST ANOTHER GLORIOUS MID-WINTER AFTERNOON IN
SOUTHEAST ARIZONA...WITH TEMPERATURES CRUISING INTO THE UPPER 70S
AGAIN IN THE LOWER DESERTS...SOME 12 DEGREES ABOVE NORMAL FOR JANUARY.
STRONG HIGH PRESSURE ALOFT OVER THE PACIFIC NORTHWEST WILL SLOWLY
TRANSLATE EASTWARD...WITH THE RIDGE AXIS OVER THE GREAT
BASIN/ROCKIES SUNDAY THROUGH TUESDAY. THIS WILL ENSURE THAT THE
FANTASTIC WEATHER WILL CONTINUE...WITH LOWER DESERTS ENJOYING UPPER
70S EACH AFTERNOON. INHERITED MAX TEMPS WERE NUDGED UPWARD TO MATCH
THE WARMER NAM MOS GUIDANCE WHICH HAS BEEN PERFORMING THE BEST
LATELY WITH THE EASTERLY DOWNSLOPE AND COMPRESSIONAL WARMING. 12Z
NAM MOS SUGGESTS SOME OF THE WARMER LOCATIONS WILL TOUCH 80 DEGREES
MONDAY AFTERNOON.
THE EXTENDED PORTION OF THE FORECAST IS FAR MORE CHALLENGING...AS WE
CONTINUE TO WAIT FOR MODEL CONSISTENCY ON THE EXPECTED PATTERN
CHANGE NEXT WEEK. IN A NUTSHELL...THE AFTERNOON FORECAST PACKAGE IS
A BLEND OF 12Z ECMWF AND THE INHERITED FORECAST...AND LARGELY
IGNORES THE 12Z GFS. 12Z MEX GUIDANCE ARGUES FOR NO MENTIONABLE POPS
THROUGH NEXT WEEK...AND IT APPEARS THAT THE DRY BIAS THAT MEX HAS
SHOWN BEFORE THIS WINTER IS AT PLAY AGAIN. FOR SEVERAL DAYS
NOW...THE ECMWF HAS SHOWN SOME CONSISTENCY SHOWING A CLOSED LOW
APPROACHING SOUTHERN CALFORNIA ON WEDNESDAY. GFS AND ECMWF DO AGREE
THAT CLOUDS WILL INCREASE IN SOUTHWESTERLY FLOW ACROSS SOUTHEAST
ARIZONA ON WEDNESDAY...AND THIS TREND WAS RETAINED IN THE SKY GRIDS.
BUT THATS WHERE THE SIMILARITY ENDS...WITH 12Z ECMWF SHOWING A
RATHER STRONG CLOSED LOW ENTERING WESTERN ARIZONA THURSDAY
MORNING...AND CROSSING THE CWA THURSDAY. ECMWF SUGGESTS WIDESPREAD
PRECIP AND MUCH COOLER TEMPERATURES THURSDAY...WHEREAS GFS WOULD
SUGGEST LOWER 70S AND DRY WEATHER. HISTORICALLY...ECMWF HAS SHOWN
BETTER SKILL WITH HANDLING PATTERN CHANGES...AND AS STATED
PREVIOUSLY ITS WET SOLUTION IS SHOWING SOME RECURRENCE IN THE MODEL
RUNS. POPS WERE INCREASED IN THE WEDNESDAY NIGHT THROUGH THURSDAY
TIME FRAME...HIGHEST ON THURSDAY WITH 30-40% POPS AND 50% IN THE
MOUNTAINS...WITH SNOW LEVELS MUCH LOWER THAN GFS WOULD SUGGEST.
AGAIN...THIS FORECAST IS BASED ON 12Z ECMWF AND THE INHERITED POP
GRIDS...AND IS NOT SUPPORTED BY 12Z GFS/MEX GUIDANCE. THE MODELS
WILL COME TO A CONSENSUS SOON...AND THE HUNCH IS GFS WILL FALL IN
LINE WITH THE ECMWF. A SIGNIFICANT PRECIP EVENT IS POSSIBLE
WEDNESDAY AND THURSDAY...BUT HARD TO SAY MUCH UNTIL GFS AGREES.
THANKFULLY...WE`RE STILL TALKING ABOUT A 4-5 DAY FORECAST AND THERE
IS PLENTY OF TIME TO ADJUST POPS UP OR DOWN.
&&
.AVIATION...MOSTLY CLEAR SKIES THROUGH SUNDAY...WITH ONLY A FEW
CIRRUS NEAR 25K FEET AGL. WINDS LIGHT AND DIURNALLY DRIVEN THROUGH
12Z SUNDAY...BECOMING EAST AT 5-15 KTS AT ALL TAF SITES AFTER 18Z
SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
TURNER
WEATHER.GOV/TUCSON
| 
