[top]
000
FXUS65 KPSR 100928
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
228 AM MST WED FEB 10 2010
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL BRING RAIN AND MOUNTAIN SNOW SHOWERS...AS
WELL AS A SLIGHT CHANCE OF THUNDERSTORMS...TO SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA THROUGH TODAY. SHOWERS WILL MOVE TO SOUTHEAST
ARIZONA BY LATE TONIGHT. DRY AND WARMER WEATHER WILL COMMENCE FRIDAY
AND CONTINUE THROUGH EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE
BECOMES ESTABLISHED OVER THE WESTERN UNITED STATES.
&&
.DISCUSSION...
CENTER OF CIRCULATION IS APPROACHING SAN DIEGO AT THIS TIME. BROAD
BAND OF SHOWERS DEVELOPED IN THE JUXTAPOSITION AREA OF WEAK MOISTURE
ADVECTION AND STRONG 500MB HEIGHT FALL ADVECTION...WHICH EXTENDED
FROM THE NORTHERN TIP OF THE GULF OF CALIFORNIA NORTH INTO SRN NV.
SMALL LINE OF THUNDERSTORMS HAS MOST RECENTLY DEVELOPED OVER AND
SOUTH OF YUMA...LIKELY ASSOCIATED WITH THE H7-H5 FRONTOGENETICAL
FORCING.
MODELS CONTINUE TO SHOW RELATIVELY GOOD AGREEMENT AND RUN-TO-RUN
CONSISTENCY WITH THE EXPECTED PATH OF THIS SYSTEM. PREFER THE 03Z
SREF DATA FOR THE DETAILS. H5 LOW WILL BEGIN TO TAKE A MORE ELY
DIRECTION THIS MORNING. STRONGEST FORCING CONTINUES TO BE FOCUSED ON
SE CA AND SW AZ THROUGH THIS MORNING WHICH IS WHERE POPS AND QPF ARE
HIGHEST AND SLIGHT CHANCES FOR THUNDERSTORMS WILL CONTINUE. AS THE
LOW MOVES ALONG THE INTERNATIONAL BORDER THIS AFTERNOON IT TAKES ON
AN INCREASINGLY POSITIVE TILT RESULTING IN A WEAKENING TREND. THUS
AS THE LOW SKIRTS TO THE SOUTH PRECIP SHOULD BE STARTING TO FALL
APART ACROSS SOUTH CENTRAL ARIZONA /INCLUDING THE PHOENIX AREA/.
GIVEN THE SATURATED BL AND HIGH CLOUD COVER HIGH TEMPERATURES ARE
STILL EXPECTED TO BE FAIRLY COOL TODAY. THE LOW CONTINUES TO MOVE
EAST TONIGHT. PRECIP CHANCES WILL QUICKLY END FROM WEST TO EAST BY
THURSDAY MORNING.
BASED ON SOUNDING INFORMATION AND SFC OBS SNOW LEVEL IS AROUND 4000
FEET CURRENTLY. AS THE COLDEST AIR WILL BE MOVING TO THE
SOUTH...MORE INTO NORTHERN BAJA AND SONORA...I EXPECT SNOW LEVELS TO
REMAIN AROUND 4000 FEET FOR SE CA AND AROUND 5000 FEET FOR SRN GILA
COUNTY. WILL CONTINUE WITH THE WINTER WEATHER ADVISORY FOR JOSHUA
TREE NATIONAL PARK - TEMPERATURES HAVE JUST RECENTLY COOLED ENOUGH
WHERE SNOW IS LIKELY BECOMING THE PREDOMINANT PRECIPITATION TYPE
ABOVE 4000 FEET.
FRIDAY INTO NEXT WEEK GFS AND ECMWF CONTINUE TO FORECAST A LONG WAVE
RIDGE DEVELOPING OVER THE WESTERN CONUS. I ZEROED OUT THE POPS
DURING THIS PERIOD AND INCREASED TEMPERATURES A BIT FROM THE CURRENT
FORECAST. ABOVE NORMAL TEMPERATURES SHOULD ARRIVE BY SATURDAY AND
REMAIN THROUGH MID-WEEK WITH PLENTY OF CLEAR SKY.
&&
.AVIATION...
KPHX AND KIWA...
THROUGH 11Z WED...SCT CLDS BASED NEAR 8 THSD WITH INCREASING HIGH
CLOUDS ABOVE. FROM 11Z TO 14Z...CLOUDS LOWERING AND BECOMING BKN 8
THSD MSL. 14Z WED THROUGH 23Z WED...BKN TO OVC CLDS BASED NEAR 5
THSD AGL WITH SCATTERED RAIN SHOWERS.
KIPL AND KBLH...
COLD FRONT APPROACHING THROUGH 14Z. CLDS LOWERING AND BECOMING BKN
TO OVC 4 TO 5 THSD FT AGL WITH SCT SHWRS AND ISOLATED THUNDERSTORMS.
VISIBILITY IN HEAVIER SHOWERS FALLING TO NEAR 3 MILES. AFT 14Z
CLOUDS BECOMING SCT TO OCNL BKN NEAR 5 THSD AGL WITH A FEW SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...ELLIS
[top]
000
FXUS66 KMTR 100635
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
835 PM PST TUE FEB 9 2010
.DISCUSSION...AS OF 8:35 PM PST TUESDAY...RAIN SHOWERS ASSOCIATED
WITH THE LOW CURRENTLY SITUATED 80 NM WEST OF POINT CONCEPTION HAVE
FOR THE MOST PART MOVED SOUTH INTO SOUTHERN CALIFORNIA THIS EVENING.
DOPPLER RADAR SHOWS A FEW LINGERING SHOWERS OFF THE MONTEREY COUNTY
COAST MOVING SOUTHWEST AT AROUND 15 KT. WOULD NOT RULE OUT A STRAY
SHOWER OVER THE SOUTHERNMOST PORTION OF THE CWA TONIGHT.
PARTLY TO MOSTLY CLOUDY CONDITIONS WILL GIVE WAY TO MOSTLY CLEAR
SKIES OVERNIGHT WHICH WILL ALLOW TEMPERATURES TO FALL INTO THE 30S
AND 40S. MILD AND DRY WEATHER IS EXPECTED WEDNESDAY BEFORE THE NEXT
COLD FRONT APPROACHED THE WEST COAST. ANTICIPATE INCREASING HIGH
CLOUDS THURSDAY WITH RAIN SHOWERS OVER THE NORTH BAY BEGINNING LATE
THURSDAY AFTERNOON OR EVENING. MODELS ARE KEEPING THE MAJORITY OF
THE PRECIPITATION CONFINED TO THE BAY AREA NORTHWARD. FORECASTS
BRING AROUND A QUARTER INCH TO THE NORTH BAY TO AS LITTLE AS A
FEW HUNDREDTHS OF AN INCH AROUND THE MONTEREY BAY AREA. RAINFALL
TOTALS WILL DEPEND ON HOW FAR SOUTH THE TROUGH DIGS ON FRIDAY.
THE HOLIDAY WEEKEND IS SHAPING UP TO BE MILD AND DRY AS A WEAK RIDGE
SETS UP ACROSS THE REGION KEEPING THE STORM TRACK WELL NORTH OF THE
DISTRICT. SIMILAR CONDITIONS WILL HOLD INTO THE FIRST HALF OF NEXT
WEEK.
&&
.AVIATION...AS OF 10:30 PM TUESDAY...CLOUDS AND SHOWERS HAVE MOVED
SOUTH OF THE SFO AND MRY BAY AREA. WITH CLEAR SKIES...FOG IS
EXPECTED TO DEVELOP OVERNIGHT AT KSTS.
VICINITY OF KSFO...VFR CONDITIONS EXPECTED THROUGH WEDNESDAY WITH
DRYING CONDITIONS. WINDS SWITCHING FROM N-NE TO NW 5-10 KT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...DECREASING CLOUDS WITH VFR CONDITIONS
THROUGH WEDNESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
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000
FXUS66 KLOX 100553
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
950 PM PST TUE FEB 9 2010
...NEW AVIATION DISCUSSION...
.SYNOPSIS...A COLD LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE OVER
THE REGION TONIGHT AND EXIT THE REGION ON WEDNESDAY. OFFSHORE
FLOW IS EXPECTED FROM THURSDAY INTO TUESDAY FOR FAIR SKIES AND
WARMER TEMPERATURES.
&&
.UPDATE...THE STORMS CENTER CURRENTLY REMAINS SKIMMING OVER THE
COASTAL AND OFFSHORE WATERS THIS EVENING. RADAR AND SATELLITE
IMAGERY INDICATE SHOWERS PUSHING INTO THE SANTA BARBARA CHANNEL
AND ACROSS THE OUTER WATERS. GOOD AGREEMENT EXISTS FOR A WRAP-
AROUND EVENT DEVELOPING FOR THE INTERIOR SLOPE AND DESERT LATE
TONIGHT AND INTO WEDNESDAY MORNING. NAM BUFR SOUNDINGS INDICATE
NORTHEAST UPSLOPE FLOW DEVELOPING LATE TONIGHT OVER THE ANTELOPE
VALLEY WITH A PLUME OF MOISTURE FROM THE SURFACE UP TO ABOUT 7000
FEET. NAM BUFR SOUNDINGS INDICATE THE FREEZING APPROACHING 4000
FEET LATER TONIGHT...BUT WITH THE UNSTABLE AIR MASS IN PLACE...A
POTENTIAL FOR CONVECTIVE BURSTS OF SNOW EXISTS FOR THE ANTELOPE
VALLEY. A WINTER WEATHER ADVISORY WAS ADDED FOR THE ANTELOPE
VALLEY AND THE WARNINGS HAVE BEEN CONTINUED FOR THE LOS ANGELES
AND VENTURA COUNTY MOUNTAINS. THE ADVISORIES FOR THE SAN LUIS
OBISPO AND SANTA BARBARA COUNTY MOUNTAINS WILL BE MONITORED
CLOSELY...AS THEY ARE MARGINAL AT THIS TIME. WITH WRAP-AROUND
POTENTIAL IN PLACE AND COOL AIR MASS ALREADY TAKING SHAPE...SNOW
SHOWERS COULD STILL PRODUCE SIGNIFICANT ACCUMULATIONS. AN UPDATE
WAS INCLUDED EARLIER TO DECREASE TEMPERATURES OVER THE INTERIOR
PORTION LATE TONIGHT...IN ADDITION TO UPDATING THE HEADLINES.
&&
.PREV DISCUSSION...
SHORT TERM...ON WEDNESDAY LOW LVL FLOW SHIFTS TO THE NORTHEAST
AS THE UPPER LOW MOVES SOUTHWEST OF THE AREA. MOISTURE IS LIMITED
BUT POSSIBLY ENOUGH TO GENERATE SOME NORTH FACING SLOPE AND
ANTELOPE VALLEY SHOWER ACTIVITY THROUGH WEDNESDAY AFTERNOON.
OTHERWISE, CLOUDS AND SHOWERS WILL BE ENDING EARLY WED MORNING
WITH A DRY BUT COOL DAY EXPECTED.
DRY WEATHER TO CONTINUE THROUGH FRIDAY AS MODELS INDICATE THE LATE
WEEK SYSTEM WILL PRETTY MUCH BE A NON-ISSUE NOW. MAYBE JUST SOME
INCREASE IN CLOUDS FOR AREAS NORTH OF PT CONCEPTION FRIDAY.
OTHERWISE, DAYTIME HIGHS WILL BE WARMING UP TO NEAR NORMAL LEVELS BY
FRIDAY AND POSSIBLY SLIGHTLY ABOVE NORMAL.
LONG TERM...DRY PATTERN THROUGH EARLY NEXT WEEK WITH WEAK TO
MODERATE OFFSHORE FLOW AND 950 TEMPS AROUND 20C. THIS TYPICALLY
PRODUCES HIGHS IN THE MID 70S AT LEAST ACROSS LOWER ELEVATIONS
SOUTH OF PT CONCEPTION AND NEAR 70 IN THE NORTH. WOULD NOT BE
SURPRISED TO SEE SOME AREAS NEAR 80 SUNDAY AND MONDAY.
&&
.AVIATION...
10/0600Z
GOOD CONFIDENCE IN MOST TAFS. CST AND VLY TAFS FROM KSBA SOUTH TO
KLGB WILL HAVE A CHANCE OF MVFR CIGS AND/OR SHOWERS. THERE IS A CHC
OF TSTMS OVER THE WATER BUT ONLY A 10 PERCENT CHANCE OF A TSTM AT A
TAF SITE. THE DESERT SITES WILL HAVE A CHANCE OF SNOW AFTER SUNRISE.
KLAX...FAIR CONFIDENCE IN TAF THROUGH 12Z THEN GOOD CONFIDENCE.
THERE IS A 30 PERCENT CHANCE THAT THERE WILL BE NO MVFR CIGS AND A
10 PERCENT CHC OF A TSTM TIL 12Z.
KBUR...FAIR CONFIDENCE IN TAF THROUGH 12Z THEN GOOD CONFIDENCE.
THERE IS A 30 PERCENT CHANCE OF MVFR CIGS AND A 10 PERCENT CHC OF A
TSTM TIL 12Z.
..NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
SYNOPSIS...SETO/HALL
PUBLIC...HALL/WOFFORD
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 100526 CCA
AFDPSR
AREA FORECAST DISCUSSION...............COR
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST TUE FEB 9 2010
CORRECTION FROM VANDENBURG SNOW LEVEL MENTIONED IN DISCUSSION
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL BRING RAIN AND MOUNTAIN SNOW SHOWERS...
AS WELL AS A SLIGHT CHANCE OF THUNDERSTORMS...OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT INTO EARLY
WEDNESDAY...AND MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA
WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL
THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN
RATHER COOL. DRY AND WARMER WEATHER WILL COMMENCE FRIDAY AND
CONTINUE THROUGH EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE BECOMES
ESTABLISHED OVER THE WESTERN UNITED STATES. TEMPERATURES WILL BE
SEVERAL DEGREES ABOVE NORMAL SATURDAY THROUGH AT LEAST NEXT TUESDAY.
&&
.DISCUSSION...
A POWERFUL DEVELOPING PACIFIC LOW PRESSURE SYSTEM THAT HAD BEEN
MOVING QUICKLY DOWN THE WEST COAST FROM OREGON MONDAY/MONDAY NIGHT
ARRIVED IN SOUTHERN CA TUESDAY AFTERNOON WITH A BANG. HEAVY RAIN...
THUNDERSTORMS AND MORE DEVELOPED FROM SANTA BARBARA TO SAN DIEGO
...AND OVER THE ADJACENT COASTAL MOUNTAINS. ITS A COLD STORM...AND
WEATHER BALLOON SOUNDINGS DETECTED THE SNOW LEVEL RANGED FROM 3000
FEET AT VANDENBURG AFB...WITH THE COLD CORE STORM CENTER...TO 5000
FEET AT SAN DIEGO. THE DRA SOUNDING NEAR LAS VEGAS DETECTED A SNOW
LEVEL AT 4800 FEET.
MODELS SO FAR ARE DOING A GREAT JOB IN THE SHORT TERM...MEANING THE
LOW PRESSURE SYSTEM CONTINUED TO MOVE SOUTH/SOUTHEAST. THE EUROPEAN
AND GFS MODELS SINK THIS SYSTEM SOUTH INTO NORTHERN BAJA CA BY 12Z
WED. THERE IS A CAVEAT THOUGH. ABUNDANT SATELLITE DERIVED 300 AND
250 MB JET STREAM WINDS...DERIVED FROM THE SUBTROPICAL CLOUD PLUME
ACROSS BAJA CA AND NORTHWEST MEXICO AT 00Z...SHOWED A SUBTROPICAL
JET SLIGHTLY IN EXCESS OF 130 KNOTS. THE CAVEAT IS...A SUBTROPICAL
JET THIS STRONG MAY SERVE TO LIMIT THE SOUTHWARD MOVEMENT OF THE LOW
PRESSURE SYSTEM...WITH THE SYSTEM TRACKING A LITTLE FARTHER NORTH
INTO SOUTHERN AZ THAN MODELS FORECAST. MORE MOISTURE AND DYNAMICS
COULD BE DIRECTED TOWARD PHOENIX AND VICINITY ON WED (OF MOST OF
SOUTH CENTRAL AZ) WITH ISOLATED THUNDERSTORMS.
BACK TO SNOWFALL. A WINTER WEATHER ADVISORY FOR JOSHUA TREE NATIONAL
PARK IN SOUTHEAST CA WILL CONTINUE TONIGHT. WE WILL OPT TO UPDATE
THE ADVISORY FOR MORE SNOW...AND TAKE THE ACCUMULATING SNOW LEVEL
DOWN TO 3500 FEET. 3 TO 5 STORM TOTAL INCHES ABOVE 3500 FEET IS NOW
EXPECTED IN JOSHUA TREE. UPDATES WILL COME OUT SHORTLY. REASONING...
APPEARS FROM THE COASTAL WEATHER BALLOON SOUNDINGS THAT THE 3000
FOOT SNOW LEVEL IS FOLLOWING THE MINUS 8 DEGREE C ISOTHERM...WHICH
MOVES INTO JOSHUA TREE AROUND 06Z OR 10 PM PST. 3000 FEET WILL BE
THE SNOW LINE...BUT ACCUMULATIONS LIKELY ABOVE 3500 FEET.
PRECIPITATION IN SOUTHEAST CA AND THE COLORADO RIVER VALLEY...SOME
HEAVY RAIN SHOWERS WITH ISOLATED THUNDERSTORMS WILL SPREAD ACROSS
THE SOUTHEAST CA DESERTS SHORTLY...THEN MOVE INTO THE COLORADO RIVER
VALLEY LATER TONIGHT. SHOWERS WILL THEN SPREAD EAST ACROSS MOST OF
SOUTHERN AZ ON WEDNESDAY AS THE UPPER LOW TRACK EAST NEAR THE
INTERNATIONAL BORDER.
UPDATES FOR THE SNOW ADVISORY WILL COME OUT SHORTLY...OTHERWISE
REMAINDER OF FORECASTS LOOK OK FOR NOW. PREVIOUS DISCUSSION BELOW
STILL APPLIES EXCEPT FOR A CHANGE IN SNOW LEVELS AND ACCUMULATIONS
IN SOUTHEAST CA.
PREVIOUS DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED SW OF SAN FRANCISCO AS OF 21Z (2 PM MST)...AND
CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS. AS MENTIONED
THIS MORNING...NUMERICAL MODELS ARE IN GOOD AGREEMENT REGARDING
TRACK OF THIS LOW...KEEPING IT ON A PATH THAT PARALLELS THE
CALIFORNIA COAST DURING THE NEXT 18 HRS...PLACING IT JUST WEST OF
SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT SLOWLY EAST ALONG THE
INTERNATIONAL BORDER TO JUST SOUTH OF THE ARIZONA-NEW MEXICO BORDER
BY 12Z THURSDAY. AS SUCH...STRONGEST FORCING/UVV AND BEST CHANCE FOR
PRECIPITATION WILL TRACK ACROSS FAR SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TONIGHT...ACROSS SOUTHERN QUARTER OF ARIZONA ON
WEDNESDAY...AND OVER SOUTHEAST ARIZONA WEDNESDAY NIGHT (PRINCIPAL
UPPER SUPPORT AND BEST CHANCE FOR PRECIPITATION DOES AN `END RUN`
AROUND SOUTH-CENTRAL ARIZONA). GIVEN ONLY MODEST MOISTURE
AVAILABILITY AS WELL AS THE FACT THE STORM WILL TRACK WELL SOUTH OF
OUR FORECAST AREA...PRECIP TOTALS FROM THIS STORM WILL BE RATHER
MODEST...LESS THAN ONE HALF INCH AT MOST LOCALES. TOTALS IN EXCESS
OF ONE THIRD INCH...BUT LESS THAN ONE HALF INCH...WILL BE MOST
LIKELY OVER FAR SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA TONIGHT
INTO WEDNESDAY MORNING...AND OVER THE HIGHER TERRAIN OF SOUTH-
CENTRAL ARIZONA WEDNESDAY NIGHT. PRECIP AMOUNTS WILL VARY QUITE A
BIT FROM SITE TO SITE...SINCE CONVECTIVE SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED. STRONG RIDGING DEVELOPS BEHIND THE LOW
THURSDAY WHICH WILL QUICKLY BRING THE THREAT OF PRECIP TO AN END.
GFS/ECMWF IN GOOD AGREEMENT THAT A MUCH DIFFERENT AND RATHER
PERSISTENT LONG WAVE PATTERN WILL BECOME ESTABLISHED THIS WEEKEND
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. RIDGE AXIS SETS UP NEAR
120W (FAR WESTERN UNITED STATES) WHILE BROAD TROUGH WILL BE CENTERED
NEAR 90W (EASTERN UNITED STATES). THIS PATTERN PROMISES TO BRING DRY
CONDITIONS WITH DAYTIME HIGHS SEVERAL DEGREES ABOVE NORMAL THIS
WEEKEND INTO EARLY NEXT WEEK...WITH WARMEST DAYTIME HIGHS TOWARD THE
END OF THIS FORECAST PACKAGE (EARLY NEXT WEEK).
&&
.AVIATION...
KPHX AND KIWA...
THROUGH 11Z WED...SCT CLDS BASED NEAR 8 THSD WITH INCREASING HIGH
CLOUDS ABOVE. FROM 11Z TO 14Z...CLOUDS LOWERING AND BECOMING BKN 8
THSD MSL. 14Z WED THROUGH 23Z WED...BKN TO OVC CLDS BASED NEAR 5
THSD AGL WITH SCATTERED RAIN SHOWERS.
KIPL AND KBLH...
COLD FRONT APPROACHING THROUGH 14Z. CLDS LOWERING AND BECOMING BKN
TO OVC 4 TO 5 THSD FT AGL WITH SCT SHWRS AND ISOLATED THUNDERSTORMS.
VISIBILITY IN HEAVIER SHOWERS FALLING TO NEAR 3 MILES. AFT 14Z
CLOUDS BECOMING SCT TO OCNL BKN NEAR 5 THSD AGL WITH A FEW SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ/DG
AVIATION...VASQUEZ
FIRE WEATHER...ELLIS
[top]
000
FXUS66 KHNX 100526 AAA
AFDHNX
AREA FORECAST DISCUSSION...UPDATED AVN SECTION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
845 PM PST TUE FEB 9 2010
.SYNOPSIS...A PACIFIC STORM WILL MOVE THROUGH THE SOUTHERN PART OF
THE FORECAST AREA...MAINLY KERN COUNTY WHERE MOUNTAIN SNOW WILL
IMPACT THE PASS LEVEL...THROUGH WEDNESDAY MORNING. PATCHY FOG WILL
RETURN TO THE SAN JOAQUIN VALLEY BY THURSDAY MORNING AS HIGH
PRESSURE BUILDS BACK OVER THE REGION.
&&
.UPDATE...UPPER LOW CONTINUES TO ROTATE JUST OFFSHORE WITH WRAP
AROUND MOISTURE PUSHING INTO THE DISTRICT FROM THE SOUTHEAST.
WHILE THE PRECIP IS NO LONGER WIDESPREAD...WILL CONTINUE TO SEE
LIGHT RAIN AND SNOW FROM FRESNO COUNTY SOUTH WITH THE BULK OF THE
PRECIP OVER KERN COUNTY. THEREFORE...WILL ALLOW THE WINTER WEATHER
PRODUCTS TO REMAIN IN PLACE THIS EVENING AS SNOW WILL LINGER
THROUGH EARLY WEDNESDAY MORNING. CURRENTLY...THE UPPER LOW IS
STILL WEST OF SANTA BARBARA AND DRIFTING SOUTH. THIS POSITION WILL
KEEP KERN COUNTY ON THE PRECIP ZONE UNTIL JUST AFTER 0400 AM
PST...AT WHICH TIME SHORT RANGE MODELS PLACE THE UPPER LOW NEAR
SAN DIEGO. HOWEVER...WILL UPDATE THE SPECIAL WEATHER STATEMENT TO
REMOVE THE MENTION OF THUNDERSTORMS OVER THE KERN COUNTY DESERTS.
WILL ALSO KEEP THE MENTION OF A LOW CHANCE OF PRECIP OVER THE KERN
COUNTY MOUNTAINS AND DESERTS THROUGH MOST OF WEDNESDAY BEFORE
CLEARING STARTS AFTER SUNSET. WHILE MERCED MAY SEE SOME SUNSHINE
ON WEDNESDAY...AREAS CLOSER TO BAKERSFIELD MAY CONTINUE TO SEE
CLOUDS ON WEDNESDAY AS MOISTURE BANKS UP NEAR THE GRAPEVINE. WILL
MAKE NO MAJOR UPDATES TO THE FORECAST THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 316 PM PST TUE FEB 9 2010/
THE UPPER LOW AND ITS ASSOCIATED SFC LOW IS PLAINLY VISIBLE ON
SAT PIX LATE THIS AFTERNOON...LOCATED OFF THE CENTRAL CA COAST
WEST OF CAMBRIA. THE LOW WILL CONT TO THE SSE THIS EVE AND BE NEAR
SAN DIEGO WED MORNING. BAROCLINIC BAND PRECIP/OCCLUSION ACROSS
INTERIOR CENT CA HAS BEEN RELATIVELY STATIONARY THE PAST FEW
HOUR...AND AS DYNAMICS WEAKEN PRECIP IS SLOWLY WINDING DOWN. FLOW
ALOFT WILL GRADUALLY TURN EAST AS UPPER LOW MOVES SOUTH. THIS WILL
BEGIN TO END PRECIP FROM NORTH TO SOUTH OVERNITE. FROM FRESNO
COUNTY NORTH...SHOWERS WILL PROBABLY BE OVER NEAR OR BEFORE
MIDNIGHT.
OVER THE SOUTH HALF OF THE CWA...IT MAY TAKE A LITTLE LONGER BUT
LIKELY TO BE OVER BEFORE SUNRISE. THE EXCEPTION BEING THE KERN
MTNS AND DESERTS...WHERE PRECIP MAY TAPER OFF A BIT THIS EVE...BUT
ACTUALLY PICK BACK UP AS THE LOW PASSES PT CONCEPTION AND UPPER
DEFORMATION/EASTERLY FLOW DEVELOPS. SNOWFALL THUS FAR HAS BEEN IN
THE 3-4 INCH RANGE IN THE CUDDY VALLEY/FRAZIER PARK AREA AND COULD
SEE AN ADDNL 4-6 BEFORE ALL IS SAID AND DONE. STILL HARD TO TELL
IF HEAVY SNOW WILL MAKE IT AS FAR EAST IN THE TEHACHAPIS AS
HIGHWAY 58. DEPENDS ON HOW MUCH UPSLOPE DEVELOPS ON THE EAST AND
SOUTH FACING SLOPES.
OTHERWISE ACROSS CENTRAL CA...A RATHER BENIGN PATTERN IS SEEN THE
REMAINDER OF THE WEEK AND THRU THE WEEKEND. AN UPPER LEVEL RIDGE
WILL GRADUALLY EXPAND OVER THE REGION...AND WHILE TEMPORARILY
BEING FLATTENED BY A COUPLE OF PAC NW SHORTWAVES...WILL HOLD ITS
GROUND INTO THE FIRST HALF OF NEXT WEEK. THUS LOOK FOR A WARMING
TREND TO BEGIN THURS AND CONT INTO THE WEEKEND. THE FLY IN THE
OINTMENT HOWEVER WILL BE HOW MUCH FOG DEVELOPS OR PERSISTS IN THE
VALLEY EACH NIGHT.
&&
.AVIATION...
AS A STORM SYSTEM SLIDES SOUTH ALONG THE SOUTHERN CALIFORNIA
COAST...SHOWERS WILL CONTINUE TO DIMINISH FROM THE NORTH. IN THE
SAN JOAQUIN VALLEY...MAINLY VFR EXCEPT SOME LOCAL MVFR IN A FEW
LINGERING SHOWERS SOUTH OF FRESNO COUNTY THROUGH 15Z WEDNESDAY.
CLEARING SKIES IN THE CENTRAL VALLEY OVERNIGHT COULD LEAD TO AREAS
OF IFR AND SOME LOCAL LIFR IN FOG THROUGH 18Z WEDNESDAY. OVER THE
SIERRA NEVADA AND TEHACHAPI MOUNTAINS...MVFR TO LCL LIFR DUE TO
MOUNTAIN OBSCURATIONS IN CLOUDS AND PRECIPITATION THROUGH 18Z
WEDNESDAY. IN THE KERN COUNTY DESERT...MAINLY VFR EXCEPT LCL MVFR
IN SHRA POSSIBLY MIXED WITH -SN THROUGH 18Z WEDNESDAY. OTHERWISE
EXPECT VFR CONDITIONS OVER THE CENTRAL CALIFORNIA INTERIOR THROUGH
06Z THURSDAY.
&&
.AIR QUALITY ISSUES...NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...WINTER WEATHER ADVISORY UNTIL
10 AM PST WEDNESDAY FOR THE TULARE COUNTY MOUNTAINS /CAZ097/.
WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY FOR THE KERN
COUNTY MOUNTAINS /CAZ095/.
&&
$$
PUBLIC...MOLINA
AVN/FW...JEB
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
000
FXUS66 KLOX 100505
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
905 PM PST TUE FEB 9 2010
.SYNOPSIS...A COLD LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE OVER
THE REGION TONIGHT AND EXIT THE REGION ON WEDNESDAY. OFFSHORE
FLOW IS EXPECTED FROM THURSDAY INTO TUESDAY FOR FAIR SKIES AND
WARMER TEMPERATURES.
&&
.UPDATE...THE STORMS CENTER CURRENTLY REMAINS SKIMMING OVER THE
COASTAL AND OFFSHORE WATERS THIS EVENING. RADAR AND SATELLITE
IMAGERY INDICATE SHOWERS PUSHING INTO THE SANTA BARBARA CHANNEL
AND ACROSS THE OUTER WATERS. GOOD AGREEMENT EXISTS FOR A WRAP-
AROUND EVENT DEVELOPING FOR THE INTERIOR SLOPE AND DESERT LATE
TONIGHT AND INTO WEDNESDAY MORNING. NAM BUFR SOUNDINGS INDICATE
NORTHEAST UPSLOPE FLOW DEVELOPING LATE TONIGHT OVER THE ANTELOPE
VALLEY WITH A PLUME OF MOISTURE FROM THE SURFACE UP TO ABOUT 7000
FEET. NAM BUFR SOUNDINGS INDICATE THE FREEZING APPROACHING 4000
FEET LATER TONIGHT...BUT WITH THE UNSTABLE AIR MASS IN PLACE...A
POTENTIAL FOR CONVECTIVE BURSTS OF SNOW EXISTS FOR THE ANTELOPE
VALLEY. A WINTER WEATHER ADVISORY WAS ADDED FOR THE ANTELOPE
VALLEY AND THE WARNINGS HAVE BEEN CONTINUED FOR THE LOS ANGELES
AND VENTURA COUNTY MOUNTAINS. THE ADVISORIES FOR THE SAN LUIS
OBISPO AND SANTA BARBARA COUNTY MOUNTAINS WILL BE MONITORED
CLOSELY...AS THEY ARE MARGINAL AT THIS TIME. WITH WRAP-AROUND
POTENTIAL IN PLACE AND COOL AIR MASS ALREADY TAKING SHAPE...SNOW
SHOWERS COULD STILL PRODUCE SIGNIFICANT ACCUMULATIONS. AN UPDATE
WAS INCLUDED EARLIER TO DECREASE TEMPERATURES OVER THE INTERIOR
PORTION LATE TONIGHT...IN ADDITION TO UPDATING THE HEADLINES.
&&
.PREV DISCUSSION...
SHORT TERM...ON WEDNESDAY LOW LVL FLOW SHIFTS TO THE NORTHEAST
AS THE UPPER LOW MOVES SOUTHWEST OF THE AREA. MOISTURE IS LIMITED
BUT POSSIBLY ENOUGH TO GENERATE SOME NORTH FACING SLOPE AND
ANTELOPE VALLEY SHOWER ACTIVITY THROUGH WEDNESDAY AFTERNOON.
OTHERWISE, CLOUDS AND SHOWERS WILL BE ENDING EARLY WED MORNING
WITH A DRY BUT COOL DAY EXPECTED.
DRY WEATHER TO CONTINUE THROUGH FRIDAY AS MODELS INDICATE THE LATE
WEEK SYSTEM WILL PRETTY MUCH BE A NON-ISSUE NOW. MAYBE JUST SOME
INCREASE IN CLOUDS FOR AREAS NORTH OF PT CONCEPTION FRIDAY.
OTHERWISE, DAYTIME HIGHS WILL BE WARMING UP TO NEAR NORMAL LEVELS BY
FRIDAY AND POSSIBLY SLIGHTLY ABOVE NORMAL.
LONG TERM...DRY PATTERN THROUGH EARLY NEXT WEEK WITH WEAK TO
MODERATE OFFSHORE FLOW AND 950 TEMPS AROUND 20C. THIS TYPICALLY
PRODUCES HIGHS IN THE MID 70S AT LEAST ACROSS LOWER ELEVATIONS
SOUTH OF PT CONCEPTION AND NEAR 70 IN THE NORTH. WOULD NOT BE
SURPRISED TO SEE SOME AREAS NEAR 80 SUNDAY AND MONDAY.
&&
.AVIATION...10/0025Z.
VFR CONDITIONS WITH CEILINGS AT OR BELOW 6000 FEET WILL CONTINUE AT
LEAST 04Z TONIGHT. CONDITIONS HAVE A CHANCE OF BECOMING MVFR THROUGH
04Z. VFR CONDITIONS SHOULD BECOME PREDOMINANT FOR COASTAL AND VALLEY
AREA AFTER 07Z...WITH BRIEF MVFR CONDITIONS IN ANY RESIDUAL SHOWERS.
AFTER 12Z...THERE IS A CHANCE OF MVFR CONDITIONS OVER THE ANTELOPE
VALLEY TERMINALS.
KLAX AND KBUR...VFR CONDITIONS WITH CEILINGS AT OR BELOW 6000 FEET
WILL PERSIST THROUGH AT LEAST 01Z...OR 02Z THIS EVENING. THERE IS A
30 PERCENT CHANCE OF MVFR CONDITIONS THROUGH 02Z. AFTER 02Z...VFR
CONDITIONS SHOULD BECOME PREDOMINANT WITH A 30 PERCENT CHANCE OF
MVFR CONDITIONS THROUGH 09Z TONIGHT.
..NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
SYNOPSIS...SETO/HALL
PUBLIC...HALL/WOFFORD
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
[top]
000
FXUS66 KSGX 100500
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST TUE FEB 9 2010
.SYNOPSIS...COLD UPPER LEVEL LOW PRESSURE WILL CONTINUE SHOWERS AND
ISOLATED THUNDERSTORMS TONIGHT...DECREASING WEDNESDAY. SNOW LEVEL
NEAR 3000 FEET. FAIR WITH A WARMING TREND THURSDAY THROUGH EARLY
NEXT WEEK UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-FRIDAY)...AREAS OF SHOWERS AND ISOLATED
THUNDERSTORMS THIS EVENING. THE 00Z NKX SOUNDING WAS MOIST AND
MODERATELY UNSTABLE WITH INCREASING WSW WINDS ALOFT. ONSHORE
GRADIENTS WITH ABOUT 3 MB SAN-IPL.
THE COLD UPPER LOW CURRENTLY CENTERED NEAR PT CONCEPTION WILL MOVE S
OFF THE COAST TONIGHT AND THEN INLAND ACROSS NRN BAJA WEDNESDAY.
DYNAMICS AND COLD UNSTABLE AIR ASSOCIATED WITH THE LOW WILL CONTINUE
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE NIGHT. THUNDERSTORMS
WILL PRODUCE SMALL HAIL AND THERE COULD BE WATERSPOUTS. WRAP AROUND
MOISTURE AND UPSLOPE SLOW WILL CONTINUE ISOLATED SHOWERS
WEDNESDAY...GENERALLY DECREASING IN COVERAGE AND INTENSITY.
ADDITIONAL RAINFALL TOTALS WILL BE QUITE VARIABLE DUE TO THE SHOWERY
NATURE OF THE PRECIP. GENERAL WIDESPREAD ADDITIONAL ACCUMULATIONS
SHOULD BE BETWEEN A QUARTER AND HALF AN INCH. SNOW LEVEL NEAR
3000 FT. LOCAL ADDITIONAL SNOW ACCUMULATIONS OF ABOUT 4 TO 8 INCHES.
SNOW WILL AFFECT THE MOUNTAIN PASSES AND THERE COULD BE LOCAL SNOW
AT THE HIGHER ELEVATIONS OF THE UPPER DESERTS. PATCHY FROST INLAND
THURSDAY MORNING. FAIR AND WARMER THURSDAY AND FRIDAY UNDER HIGH
PRESSURE.
&&
.LONG TERM (SATURDAY-TUESDAY)...STRONG HIGH PRESSURE ALOFT AND
INTERMITTENT WEAK OFFSHORE FLOW WILL CONTINUE FAIR AND WARMER
WEATHER. MAX TEMPS SHOULD GET ABOUT 5 TO 10 DEGREES ABOVE SEASONAL
AVERAGES BY EARLY NEXT WEEK.
&&
.AVIATION...
100400Z...SCATTERED SHOWERS WILL CONTINUE THROUGH ABOUT 08Z WITH
VARIABLE CIGS FROM FL025 TO FL070. COASTAL SLOPES WILL BE OBSCURED
IN CLOUDS AND PCPN. GENERALLY VFR CONDITIONS TO FOLLOW THROUGH WED
MORNING WITH BKN-OVC CIGS BETWEEN FL035 AND FL050 AND ISOLATED LIGHT
SHOWERS...EXCEPT IN THE MOUNTAINS WHERE THE HIGHER TERRAIN WILL
REMAIN OBSCURED IN CLOUDS AND LIGHT SNOW. SOME MID-LEVEL
CLOUDS/MOISTURE WILL WRAP INTO THE AREA FROM THE EAST ON WED BUT ANY
PRECIPITATION SHOULD BE VERY LIGHT AND MOSTLY IN THE MOUNTAINS.
.MARINE...
COLD UPPER LOW MOVING OVER THE COASTAL WATERS THROUGH 15Z WED WILL
CONTINUE A CHANCE OF ISOLATED THUNDERSTORMS AND WATERSPOUTS.
OTHERWISE...SCATTERED SHOWERS ARE STILL LIKELY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM PST WEDNESDAY FOR THE MOUNTAINS
AND UPPER DESERTS. SEE LAXWSWSGX.
FLASH FLOOD WATCH THROUGH 6 AM PST WEDNESDAY FOR ORANGE COUNTY...THE
INLAND EMPIRE AND SANTA ANA MOUNTAIN FOOTHILLS. SEE LAXFFASGX.
MARINE WEATHER STATEMENT THROUGH WEDNESDAY MORNING FOR THE COASTAL
WATERS. SEE LAXMWSSGX.
&&
$$
PUBLIC...ATKIN
AVIATION/MARINE...JAD
000
FXUS66 KHNX 100445
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
845 PM PST TUE FEB 9 2010
.SYNOPSIS...A PACIFIC STORM WILL MOVE THROUGH THE SOUTHERN PART OF
THE FORECAST AREA...MAINLY KERN COUNTY WHERE MOUNTAIN SNOW WILL
IMPACT THE PASS LEVEL...THROUGH WEDNESDAY MORNING. PATCHY FOG WILL
RETURN TO THE SAN JOAQUIN VALLEY BY THURSDAY MORNING AS HIGH
PRESSURE BUILDS BACK OVER THE REGION.
&&
.UPDATE...UPPER LOW CONTINUES TO ROTATE JUST OFFSHORE WITH WRAP
AROUND MOISTURE PUSHING INTO THE DISTRICT FROM THE SOUTHEAST.
WHILE THE PRECIP IS NO LONGER WIDESPREAD...WILL CONTINUE TO SEE
LIGHT RAIN AND SNOW FROM FRESNO COUNTY SOUTH WITH THE BULK OF THE
PRECIP OVER KERN COUNTY. THEREFORE...WILL ALLOW THE WINTER WEATHER
PRODUCTS TO REMAIN IN PLACE THIS EVENING AS SNOW WILL LINGER
THROUGH EARLY WEDNESDAY MORNING. CURRENTLY...THE UPPER LOW IS
STILL WEST OF SANTA BARBARA AND DRIFTING SOUTH. THIS POSITION WILL
KEEP KERN COUNTY ON THE PRECIP ZONE UNTIL JUST AFTER 0400 AM
PST...AT WHICH TIME SHORT RANGE MODELS PLACE THE UPPER LOW NEAR
SAN DIEGO. HOWEVER...WILL UPDATE THE SPECIAL WEATHER STATEMENT TO
REMOVE THE MENTION OF THUNDERSTORMS OVER THE KERN COUNTY DESERTS.
WILL ALSO KEEP THE MENTION OF A LOW CHANCE OF PRECIP OVER THE KERN
COUNTY MOUNTAINS AND DESERTS THROUGH MOST OF WEDNESDAY BEFORE
CLEARING STARTS AFTER SUNSET. WHILE MERCED MAY SEE SOME SUNSHINE
ON WEDNESDAY...AREAS CLOSER TO BAKERSFIELD MAY CONTINUE TO SEE
CLOUDS ON WEDNESDAY AS MOISTURE BANKS UP NEAR THE GRAPEVINE. WILL
MAKE NO MAJOR UPDATES TO THE FORECAST THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 316 PM PST TUE FEB 9 2010/
THE UPPER LOW AND ITS ASSOCIATED SFC LOW IS PLAINLY VISIBLE ON
SAT PIX LATE THIS AFTERNOON...LOCATED OFF THE CENTRAL CA COAST
WEST OF CAMBRIA. THE LOW WILL CONT TO THE SSE THIS EVE AND BE NEAR
SAN DIEGO WED MORNING. BAROCLINIC BAND PRECIP/OCCLUSION ACROSS
INTERIOR CENT CA HAS BEEN RELATIVELY STATIONARY THE PAST FEW
HOUR...AND AS DYNAMICS WEAKEN PRECIP IS SLOWLY WINDING DOWN. FLOW
ALOFT WILL GRADUALLY TURN EAST AS UPPER LOW MOVES SOUTH. THIS WILL
BEGIN TO END PRECIP FROM NORTH TO SOUTH OVERNITE. FROM FRESNO
COUNTY NORTH...SHOWERS WILL PROBABLY BE OVER NEAR OR BEFORE
MIDNIGHT.
OVER THE SOUTH HALF OF THE CWA...IT MAY TAKE A LITTLE LONGER BUT
LIKELY TO BE OVER BEFORE SUNRISE. THE EXCEPTION BEING THE KERN
MTNS AND DESERTS...WHERE PRECIP MAY TAPER OFF A BIT THIS EVE...BUT
ACTUALLY PICK BACK UP AS THE LOW PASSES PT CONCEPTION AND UPPER
DEFORMATION/EASTERLY FLOW DEVELOPS. SNOWFALL THUS FAR HAS BEEN IN
THE 3-4 INCH RANGE IN THE CUDDY VALLEY/FRAZIER PARK AREA AND COULD
SEE AN ADDNL 4-6 BEFORE ALL IS SAID AND DONE. STILL HARD TO TELL
IF HEAVY SNOW WILL MAKE IT AS FAR EAST IN THE TEHACHAPIS AS
HIGHWAY 58. DEPENDS ON HOW MUCH UPSLOPE DEVELOPS ON THE EAST AND
SOUTH FACING SLOPES.
OTHERWISE ACROSS CENTRAL CA...A RATHER BENIGN PATTERN IS SEEN THE
REMAINDER OF THE WEEK AND THRU THE WEEKEND. AN UPPER LEVEL RIDGE
WILL GRADUALLY EXPAND OVER THE REGION...AND WHILE TEMPORARILY
BEING FLATTENED BY A COUPLE OF PAC NW SHORTWAVES...WILL HOLD ITS
GROUND INTO THE FIRST HALF OF NEXT WEEK. THUS LOOK FOR A WARMING
TREND TO BEGIN THURS AND CONT INTO THE WEEKEND. THE FLY IN THE
OINTMENT HOWEVER WILL BE HOW MUCH FOG DEVELOPS OR PERSISTS IN THE
VALLEY EACH NIGHT.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...VFR EXCEPT AREAS MVFR DUE TO LOWERING
CEILINGS AND VISIBILITY IN -RA/BR THROUGH 18Z WEDNESDAY...AFT 18Z
VFR THROUGH 00Z. OVER THE SIERRA NEVADA AND TEHACHAPI
MOUNTAINS...MVFR TO LCL LIFR DUE TO MOUNTAIN OBSCURATIONS IN CLOUDS
AND PRECIPITATION. IN THE KERN COUNTY DESERT...VFR EXCEPT LCL MVFR
IN SHRA POSSIBLY MIXED WITH -SN AFTER 04Z WEDNESDAY. ISOLATED TRW TIL
04Z WEDNESDAY.
&&
.AIR QUALITY ISSUES...NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...WINTER WEATHER ADVISORY UNTIL
10 AM PST WEDNESDAY FOR THE TULARE COUNTY MOUNTAINS /CAZ097/.
WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY FOR THE KERN
COUNTY MOUNTAINS /CAZ095/.
&&
$$
PUBLIC...MOLINA
AVN/FW...JEB
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
000
FXUS66 KMTR 100437
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
835 PM PST TUE FEB 9 2010
.DISCUSSION...AS OF 8:35 PM PST TUESDAY...RAIN SHOWERS ASSOCIATED
WITH THE LOW CURRENTLY SITUATED 80 NM WEST OF POINT CONCEPTION HAVE
FOR THE MOST PART MOVED SOUTH INTO SOUTHERN CALIFORNIA THIS EVENING.
DOPPLER RADAR SHOWS A FEW LINGERING SHOWERS OFF THE MONTEREY COUNTY
COAST MOVING SOUTHWEST AT AROUND 15 KT. WOULD NOT RULE OUT A STRAY
SHOWER OVER THE SOUTHERNMOST PORTION OF THE CWA TONIGHT.
PARTLY TO MOSTLY CLOUDY CONDITIONS WILL GIVE WAY TO MOSTLY CLEAR
SKIES OVERNIGHT WHICH WILL ALLOW TEMPERATURES TO FALL INTO THE 30S
AND 40S. MILD AND DRY WEATHER IS EXPECTED WEDNESDAY BEFORE THE NEXT
COLD FRONT APPROACHED THE WEST COAST. ANTICIPATE INCREASING HIGH
CLOUDS THURSDAY WITH RAIN SHOWERS OVER THE NORTH BAY BEGINNING LATE
THURSDAY AFTERNOON OR EVENING. MODELS ARE KEEPING THE MAJORITY OF
THE PRECIPITATION CONFINED TO THE BAY AREA NORTHWARD. FORECASTS
BRING AROUND A QUARTER INCH TO THE NORTH BAY TO AS LITTLE AS A
FEW HUNDREDTHS OF AN INCH AROUND THE MONTEREY BAY AREA. RAINFALL
TOTALS WILL DEPEND ON HOW FAR SOUTH THE TROUGH DIGS ON FRIDAY.
THE HOLIDAY WEEKEND IS SHAPING UP TO BE MILD AND DRY AS A WEAK RIDGE
SETS UP ACROSS THE REGION KEEPING THE STORM TRACK WELL NORTH OF THE
DISTRICT. SIMILAR CONDITIONS WILL HOLD INTO THE FIRST HALF OF NEXT
WEEK.
&&
.AVIATION...AS OF 4:00 PM TUESDAY...SHOWERS HAVE MOVED SOUTH
OF THE SFO BAY AREA. A FEW SHOWERS WILL CONTINUE OVER THE MRY
BAY AREA THROUGH 03Z. WINDS IN THE SFO BAY AREA WILL SWITCH
FROM THE NORTHEAST TO THE NORTHWEST 5-10 KT. PATCHY FOG MAY FORM
OVERNIGHT AROUND KSTS.
VICINITY OF KSFO...VFR CONDITIONS EXPECTED THROUGH WEDNESDAY WITH
DRYING CONDITIONS. WINDS SWITCHING FROM N-NE TO NW 5-10 KT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...CIGS 4000-5000 FEET WITH A FEW SHOWERS
THROUGH 03Z. DECREASING CLOUDS WITH VFR CONDITIONS AFTER 03Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: MM/W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
[top]
000
FXUS66 KSTO 100427
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
800 PM PST TUE FEB 9 2010
.DISCUSSION...
.UPDATE...
UPPER LOW NOW NEAR SANTA BARBARA AND SKIES HAVE CLEARED OUT ACROSS
THE REGION. TEMPERATURES AND DEW POINTS ARE DOWN SEVERAL DEGREES
FROM THIS TIME YESTERDAY...EXPECT OVERNIGHT LOWS IN THE UPPER 30S
NEAR THE CITIES TO THE LOWER 30S IN RURAL AREAS. PATCHES OF FROST
ARE POSSIBLE AS WE EXPECT HIGH CLOUDS TO REMAIN FAIRLY THIN UNTIL
LATER TOMORROW. KDAX SHOWS SOME WEAK ECHOES STILL WRAPPING AROUND
THE LOW NEAR THE SIERRA CREST AND NORTHERN SAN JOAQUIN COUNTY.
ISSUED MINOR FORECAST UPDATES FOR CLOUD COVER AND TEMPERATURES. SG
.PREVIOUS DISCUSSION (ISSUED 3:30 PM TUESDAY)...
SURFACE LOW NOW NEAR MONTEREY BAY AND THE THREAT OF THUNDERSTORMS
HAS DIMINISHED ACROSS THE REGION. WRAP AROUND SNOW SHOWERS WILL
CONTINUE NEAR THE SIERRA CREST THIS EVENING BEFORE TAPERING OFF
OVERNIGHT. PATCHY FOG WILL DEVELOP OVERNIGHT...DO NOT BELIEVE IT
WILL BE THAT THICK AS OVERRUNNING HIGH CLOUDS ARE MOVING RAPIDLY
INLAND TOWARD THE COAST. THESE WILL INCREASE BY TOMORROW AFTERNOON
AS TEMPERATURES WARM INTO THE UPPER 50S. WARM FRONT APPROACHES THE
COAST THURSDAY AFTERNOON. THE 18Z GFS BRINGS THE THREAT OF SHOWERS
INTO THE SHASTA COUNTY MOUNTAINS THURSDAY EVENING...THEN A COLD
FRONT MAY BRING A BETTER CHANCE OF SHOWERS THURSDAY NIGHT AND
FRIDAY. THE NEGATIVE TILT SHORTWAVE THAT MOVES THROUGH FRIDAY HAS
LIMITED DYNAMICS BUT WILL BE FARTHER NORTH AS STRONG RIDGING BECOMES
RE-ESTABLISHED OVER THE INTERMOUNTAIN STATES. WE LOWERED THE CHANCES
OF SHOWERS IN OUR SOUTHERN AREAS FRIDAY AS THE ECMWF WAS MORE
PROGRESSIVE WITH THE SHORTWAVE AND HAS HIGH PRESSURE REBUILDING
FASTER. SG
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)...DRIER AND WARMER
OVER INTERIOR NORCAL SATURDAY AS THE AREA COMES UNDER THE INFLUENCE
OF UPPER RIDGING. COLD FRONT BRUSHES ACROSS FAR NORTHERN PORTIONS OF
INTERIOR NORCAL SUNDAY BRINGING A SLIGHT CHANCE OF SHOWERS. MODELS
SHOW RIDGING THEN STRENGTHENING AGAIN INTO MONDAY FOLLOWED BY A
SLIGHT CHANCE OF SOME LIGHT OVERRUNNING PRECIP OVER THE FAR NORTHERN
INTERIOR TUESDAY.
&&
.AVIATION...
VFR CONDS NOW DOMINATE THE VALLEY TAF SITES AND MOST OF OUR CWA.
THERE ARE A FEW LOCAL SPOTS OF MVFR/IFR CIGS ALONG THE
FOOTHILLS...SUCH AS KAUN AND KPVF. LIGHT WINDS CONTINUE THROUGH
TOMORROW AT TAF SITES. PATCHY FOG COULD DEVELOP IN PORTIONS OF THE
VALLEY WED MORNING CAUSING MVFR/IFR CONDS BUT MOST OF IT SHOULD BE
LIMITED TO 12-17Z. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPSR 100325
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
825 PM MST TUE FEB 9 2010
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL BRING RAIN AND MOUNTAIN SNOW SHOWERS...
AS WELL AS A SLIGHT CHANCE OF THUNDERSTORMS...OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT INTO EARLY
WEDNESDAY...AND MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA
WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL
THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN
RATHER COOL. DRY AND WARMER WEATHER WILL COMMENCE FRIDAY AND
CONTINUE THROUGH EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE BECOMES
ESTABLISHED OVER THE WESTERN UNITED STATES. TEMPERATURES WILL BE
SEVERAL DEGREES ABOVE NORMAL SATURDAY THROUGH AT LEAST NEXT TUESDAY.
&&
.DISCUSSION...
A POWERFUL DEVELOPING PACIFIC LOW PRESSURE SYSTEM THAT HAD BEEN
MOVING QUICKLY DOWN THE WEST COAST FROM OREGON MONDAY/MONDAY NIGHT
ARRIVED IN SOUTHERN CA TUESDAY AFTERNOON WITH A BANG. HEAVY RAIN...
THUNDERSTORMS AND MORE DEVELOPED FROM SANTA BARBARA TO SAN DIEGO
...AND OVER THE ADJACENT COASTAL MOUNTAINS. ITS A COLD STORM...AND
WEATHER BALLOON SOUNDINGS DETECTED THE SNOW LEVEL RANGED FROM 2000
FEET AT VANDENBURG AFB...WITH THE COLD CORE STORM CENTER...TO 5000
FEET AT SAN DIEGO. THE DRA SOUNDING NEAR LAS VEGAS DETECTED A SNOW
LEVEL AT 4800 FEET.
MODELS SO FAR ARE DOING A GREAT JOB IN THE SHORT TERM...MEANING THE
LOW PRESSURE SYSTEM CONTINUED TO MOVE SOUTH/SOUTHEAST. THE EUROPEAN
AND GFS MODELS SINK THIS SYSTEM SOUTH INTO NORTHERN BAJA CA BY 12Z
WED. THERE IS A CAVEAT THOUGH. ABUNDANT SATELLITE DERIVED 300 AND
250 MB JET STREAM WINDS...DERIVED FROM THE SUBTROPICAL CLOUD PLUME
ACROSS BAJA CA AND NORTHWEST MEXICO AT 00Z...SHOWED A SUBTROPICAL
JET SLIGHTLY IN EXCESS OF 130 KNOTS. THE CAVEAT IS...A SUBTROPICAL
JET THIS STRONG MAY SERVE TO LIMIT THE SOUTHWARD MOVEMENT OF THE LOW
PRESSURE SYSTEM...WITH THE SYSTEM TRACKING A LITTLE FARTHER NORTH
INTO SOUTHERN AZ THAN MODELS FORECAST. MORE MOISTURE AND DYNAMICS
COULD BE DIRECTED TOWARD PHOENIX AND VICINITY ON WED (OF MOST OF
SOUTH CENTRAL AZ) WITH ISOLATED THUNDERSTORMS.
BACK TO SNOWFALL. A WINTER WEATHER ADVISORY FOR JOSHUA TREE NATIONAL
PARK IN SOUTHEAST CA WILL CONTINUE TONIGHT. WE WILL OPT TO UPDATE
THE ADVISORY FOR MORE SNOW...AND TAKE THE ACCUMULATING SNOW LEVEL
DOWN TO 3500 FEET. 3 TO 5 STORM TOTAL INCHES ABOVE 3500 FEET IS NOW
EXPECTED IN JOSHUA TREE. UPDATES WILL COME OUT SHORTLY. REASONING...
APPEARS FROM THE COASTAL WEATHER BALLOON SOUNDINGS THAT THE 3000
FOOT SNOW LEVEL IS FOLLOWING THE MINUS 8 DEGREE C ISOTHERM...WHICH
MOVES INTO JOSHUA TREE AROUND 06Z OR 10 PM PST. 3000 FEET WILL BE
THE SNOW LINE...BUT ACCUMULATIONS LIKELY ABOVE 3500 FEET.
PRECIPITATION IN SOUTHEAST CA AND THE COLORADO RIVER VALLEY...SOME
HEAVY RAIN SHOWERS WITH ISOLATED THUNDERSTORMS WILL SPREAD ACROSS
THE SOUTHEAST CA DESERTS SHORTLY...THEN MOVE INTO THE COLORADO RIVER
VALLEY LATER TONIGHT. SHOWERS WILL THEN SPREAD EAST ACROSS MOST OF
SOUTHERN AZ ON WEDNESDAY AS THE UPPER LOW TRACK EAST NEAR THE
INTERNATIONAL BORDER.
UPDATES FOR THE SNOW ADVISORY WILL COME OUT SHORTLY...OTHERWISE
REMAINDER OF FORECASTS LOOK OK FOR NOW. PREVIOUS DISCUSSION BELOW
STILL APPLIES EXCEPT FOR A CHANCE IN SNOW LEVELS AND ACCUMULATIONS
IN SOUTHEAST CA.
PREVIOUS DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED SW OF SAN FRANCISCO AS OF 21Z (2 PM MST)...AND
CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS. AS MENTIONED
THIS MORNING...NUMERICAL MODELS ARE IN GOOD AGREEMENT REGARDING
TRACK OF THIS LOW...KEEPING IT ON A PATH THAT PARALLELS THE
CALIFORNIA COAST DURING THE NEXT 18 HRS...PLACING IT JUST WEST OF
SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT SLOWLY EAST ALONG THE
INTERNATIONAL BORDER TO JUST SOUTH OF THE ARIZONA-NEW MEXICO BORDER
BY 12Z THURSDAY. AS SUCH...STRONGEST FORCING/UVV AND BEST CHANCE FOR
PRECIPITATION WILL TRACK ACROSS FAR SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TONIGHT...ACROSS SOUTHERN QUARTER OF ARIZONA ON
WEDNESDAY...AND OVER SOUTHEAST ARIZONA WEDNESDAY NIGHT (PRINCIPAL
UPPER SUPPORT AND BEST CHANCE FOR PRECIPITATION DOES AN `END RUN`
AROUND SOUTH-CENTRAL ARIZONA). GIVEN ONLY MODEST MOISTURE
AVAILABILITY AS WELL AS THE FACT THE STORM WILL TRACK WELL SOUTH OF
OUR FORECAST AREA...PRECIP TOTALS FROM THIS STORM WILL BE RATHER
MODEST...LESS THAN ONE HALF INCH AT MOST LOCALES. TOTALS IN EXCESS
OF ONE THIRD INCH...BUT LESS THAN ONE HALF INCH...WILL BE MOST
LIKELY OVER FAR SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA TONIGHT
INTO WEDNESDAY MORNING...AND OVER THE HIGHER TERRAIN OF SOUTH-
CENTRAL ARIZONA WEDNESDAY NIGHT. PRECIP AMOUNTS WILL VARY QUITE A
BIT FROM SITE TO SITE...SINCE CONVECTIVE SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED. STRONG RIDGING DEVELOPS BEHIND THE LOW
THURSDAY WHICH WILL QUICKLY BRING THE THREAT OF PRECIP TO AN END.
GFS/ECMWF IN GOOD AGREEMENT THAT A MUCH DIFFERENT AND RATHER
PERSISTENT LONG WAVE PATTERN WILL BECOME ESTABLISHED THIS WEEKEND
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. RIDGE AXIS SETS UP NEAR
120W (FAR WESTERN UNITED STATES) WHILE BROAD TROUGH WILL BE CENTERED
NEAR 90W (EASTERN UNITED STATES). THIS PATTERN PROMISES TO BRING DRY
CONDITIONS WITH DAYTIME HIGHS SEVERAL DEGREES ABOVE NORMAL THIS
WEEKEND INTO EARLY NEXT WEEK...WITH WARMEST DAYTIME HIGHS TOWARD THE
END OF THIS FORECAST PACKAGE (EARLY NEXT WEEK).
&&
.AVIATION...
KPHX AND KIWA...
THROUGH 11Z WED...SCT CLDS BASED NEAR 8 THSD WITH INCREASING HIGH
CLOUDS ABOVE. FROM 11Z TO 14Z...CLOUDS LOWERING AND BECOMING BKN 8
THSD MSL. 14Z WED THROUGH 23Z WED...BKN TO OVC CLDS BASED NEAR 5
THSD AGL WITH SCATTERED RAIN SHOWERS.
KIPL AND KBLH...
COLD FRONT APPROACHING THROUGH 14Z. CLDS LOWERING AND BECOMING BKN
TO OVC 4 TO 5 THSD FT AGL WITH SCT SHWRS AND ISOLATED THUNDERSTORMS.
VISIBILITY IN HEAVIER SHOWERS FALLING TO NEAR 3 MILES. AFT 14Z
CLOUDS BECOMING SCT TO OCNL BKN NEAR 5 THSD AGL WITH A FEW SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ/DG
AVIATION...VASQUEZ
FIRE WEATHER...ELLIS
000
FXUS66 KLOX 100025
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
425 PM PST TUE FEB 9 2010
...UPDATED AVIATION SECTION...
.SYNOPSIS...
A COLD STORM SYSTEM WILL BRING SHOWERS AND LOW ELEVATION
SNOW...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS INTO EARLY
WEDNESDAY. DRY WEATHER EXPECTED THE REST OF THE WEEK WITH DAYTIME
HIGHS RISING TO WELL ABOVE NORMAL FOR THE WEEKEND.
&&
.SHORT TERM (TODAY-FRI)...UPPER LOW JUST OFF THE MONTEREY COUNTY
COAST, THE CENTER OF WHICH IS JUST WEST OF MODEL INITIALIZATIONS.
THE FIRST BAND OF SHOWERS MOVED THROUGH THIS MORNING THROUGH EARLY
AFTERNOON AND BROUGHT PERIODS OF HEAVY RAIN AND SCATTERED
THUNDERSTORMS. DECENT UPPER LEVEL DIVERGENCE IS HELPING TO ENHANCE
PRECIPITATION RATES, ESPECIALLY OVER LA COUNTY THIS AFTERNOON WITH
THIS EXPECTED TO CONTINUE THROUGH THE EARLY EVENING HOURS. LOCAL
MODELS INDICATE THE POTENTIAL FOR RAINFALL RATES TO EXCEED A HALF
INCH PER HOUR, ESPECIALLY IN LA COUNTY THROUGH THE EARLY EVENING SO
FLASH FLOOD WATCH LOOKS GOOD FOR THE BURN AREAS.
A SECOND AREA OF SHOWERS IS MOVING INTO THE CENTRAL COAST THIS
AFTERNOON JUST AHEAD OF THE COLD CORE LOW. A LITTLE SURPRISED THAT
LIGHTNING ACTIVITY HAS BEEN SO MINIMAL WITH THE LOW CENTER BUT I
EXPECT AS IT MOVES SOUTH OVER WARMER WATERS AND A MORE UNSTABLE
AIRMASS OVERALL CONVECTIVE ACTIVITY WILL INCREASE. HOWEVER, LATEST
MODELS TRENDED FURTHER WEST WITH THE TRACK OF THE LOW CENTER,
HINTING THAT THE BULK OF THE HEAVIER RAIN WITH THE CORE LOW WILL
REMAIN OFFSHORE WITH JUST SCATTERED SHOWERS OVER LAND. BASED ON
THESE TRENDS POPS WERE SCALED BACK A BIT OVER LAND AND ESPECIALLY
NORTH OF PT CONCEPTION AFTER MIDNIGHT AS THE LOW PASSES TO THE
SOUTH.
ON WEDNESDAY LOW LVL FLOW SHIFTS TO THE NORTHEAST AS THE UPPER LOW
MOVES SOUTHWEST OF THE AREA. MOISTURE IS LIMITED BUT POSSIBLY ENOUGH
TO GENERATE SOME NORTH FACING SLOPE AND ANTELOPE VALLEY SHOWER
ACTIVITY THROUGH WEDNESDAY AFTERNOON. OTHERWISE, CLOUDS AND SHOWERS
WILL BE ENDING EARLY WED MORNING WITH A DRY BUT COOL DAY EXPECTED.
DRY WEATHER TO CONTINUE THROUGH FRIDAY AS MODELS INDICATE THE LATE
WEEK SYSTEM WILL PRETTY MUCH BE A NON-ISSUE NOW. MAYBE JUST SOME
INCREASE IN CLOUDS FOR AREAS NORTH OF PT CONCEPTION FRIDAY.
OTHERWISE, DAYTIME HIGHS WILL BE WARMING UP TO NEAR NORMAL LEVELS BY
FRIDAY AND POSSIBLY SLIGHTLY ABOVE NORMAL.
.LONG TERM (SAT-TUE)...DRY PATTERN THROUGH EARLY NEXT WEEK WITH WEAK
TO MODERATE OFFSHORE FLOW AND 950 TEMPS AROUND 20C. THIS TYPICALLY
PRODUCES HIGHS IN THE MID 70S AT LEAST ACROSS LOWER ELEVATIONS SOUTH
OF PT CONCEPTION AND NEAR 70 IN THE NORTH. WOULD NOT BE SURPRISED TO
SEE SOME AREAS NEAR 80 SUNDAY AND MONDAY.
&&
.AVIATION...10/0025Z.
VFR CONDITIONS WITH CEILINGS AT OR BELOW 6000 FEET WILL CONTINUE AT
LEAST 04Z TONIGHT. CONDITIONS HAVE A CHANCE OF BECOMING MVFR THROUGH
04Z. VFR CONDITIONS SHOULD BECOME PREDOMINANT FOR COASTAL AND VALLEY
AREA AFTER 07Z...WITH BRIEF MVFR CONDITIONS IN ANY RESIDUAL SHOWERS.
AFTER 12Z...THERE IS A CHANCE OF MVFR CONDITIONS OVER THE ANTELOPE
VALLEY TERMINALS.
KLAX AND KBUR...VFR CONDITIONS WITH CEILINGS AT OR BELOW 6000 FEET
WILL PERSIST THROUGH AT LEAST 01Z...OR 02Z THIS EVENING. THERE IS A
30 PERCENT CHANCE OF MVFR CONDITIONS THROUGH 02Z. AFTER 02Z...VFR
CONDITIONS SHOULD BECOME PREDOMINANT WITH A 30 PERCENT CHANCE OF
MVFR CONDITIONS THROUGH 09Z TONIGHT.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...WOFFORD
AVIATION...HALL
SYNOPSIS...BARTLING
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSTO 100008
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 PM PST TUE FEB 9 2010
.DISCUSSION...
.UPDATE...
SURFACE LOW NOW NEAR MONTEREY BAY AND THE THREAT OF THUNDERSTORMS
HAS DIMINISHED ACROSS THE REGION. WRAP AROUND SNOW SHOWERS WILL
CONTINUE NEAR THE SIERRA CREST THIS EVENING BEFORE TAPERING OFF
OVERNIGHT. PATCHY FOG WILL DEVELOP OVERNIGHT...DO NOT BELIEVE IT
WILL BE THAT THICK AS OVERRUNNING HIGH CLOUDS ARE MOVING RAPIDLY
INLAND TOWARD THE COAST. THESE WILL INCREASE BY TOMORROW AFTERNOON
AS TEMPERATURES WARM INTO THE UPPER 50S. WARM FRONT APPROACHES THE
COAST THURSDAY AFTERNOON. THE 18Z GFS BRINGS THE THREAT OF SHOWERS
INTO THE SHASTA COUNTY MOUNTAINS THURSDAY EVENING...THEN A COLD
FRONT MAY BRING A BETTER CHANCE OF SHOWERS THURSDAY NIGHT AND
FRIDAY. THE NEGATIVE TILT SHORTWAVE THAT MOVES THROUGH FRIDAY HAS
LIMITED DYNAMICS BUT WILL BE FARTHER NORTH THIS TIME AS STRONG
RIDGING BECOMES RE-ESTABLISHED OVER THE INTERMOUNTAIN STATES. WE
LOWERED THE CHANCES OF SHOWERS IN OUR SOUTHERN AREAS FRIDAY AS THE
ECMWF WAS MORE PROGRESSIVE WITH THE SHORTWAVE AND HAS HIGH PRESSURE
REBUILDING FASTER. SG
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)...DRIER AND WARMER
OVER INTERIOR NORCAL SATURDAY AS THE AREA COMES UNDER THE INFLUENCE
OF UPPER RIDGING. COLD FRONT BRUSHES ACROSS FAR NORTHERN PORTIONS OF
INTERIOR NORCAL SUNDAY BRINGING A SLIGHT CHANCE OF SHOWERS. MODELS
SHOW RIDGING THEN STRENGTHENING AGAIN INTO MONDAY FOLLOWED BY A
SLIGHT CHANCE OF SOME LIGHT OVERRUNNING PRECIP OVER THE FAR NORTHERN
INTERIOR TUESDAY.
&&
.AVIATION...
VFR CONDS OVER THE NRN SAC VLY AND SURROUNDING MTNS AS UPR LOW IS
NOW CENTERED SOUTH OF MONTEREY BAY MOVING SOUTHWARD. VFR WITH LCL
MVFR CIGS THROUGHOUT THE CENTRAL SAC VLY INTO THE NRN SAN JOAQUIN
VLY. LIGHT WINDS CONTINUE THROUGH TOMORROW AT TAF SITES. PATCHY FOG
COULD AFFECT PORTIONS OF THE VALLEY WED MORNING CAUSING MVFR/IFR
CONDS. W SLPS OF SIERNEV FLUCTUATING FROM IFR TO VFR CIGS BUT WILL
IMPROVE TO MORE WIDESPREAD VFR BETWEEN 00-06Z WED. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 092316
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
316 PM PST TUE FEB 9 2010
.SYNOPSIS...
A PACIFIC STORM WILL MOVE THROUGH THE CENTRAL CALIFORNIA INTERIOR
TODAY THROUGH WEDNESDAY MORNING. THE HEAVIEST PRECIPITATION WILL BE
TONIGHT...WITH MOUNTAIN SNOW DOWN TO THE PASS LEVEL IN KERN COUNTY.
PATCHY FOG WILL RETURN THURSDAY MORNING A HIGH PRESSURE BUILDS BACK
OVER THE REGION.
&&
.DISCUSSION...THE UPPER LOW AND ITS ASSOCIATED SFC LOW IS PLAINLY
VISIBLE ON SAT PIX LATE THIS AFTERNOON...LOCATED OFF THE CENTRAL
CA COAST WEST OF CAMBRIA. THE LOW WILL CONT TO THE SSE THIS EVE
AND BE NEAR SAN DIEGO WED MORNING. BAROCLINIC BAND
PRECIP/OCCLUSION ACROSS INTERIOR CENT CA HAS BEEN RELATIVELY
STATIONARY THE PAST FEW HOUR...AND AS DYNAMICS WEAKEN PRECIP IS
SLOWLY WINDING DOWN. FLOW ALOFT WILL GRADUALLY TURN EAST AS UPPER
LOW MOVES SOUTH. THIS WILL BEGIN TO END PRECIP FROM NORTH TO SOUTH
OVERNITE. FROM FRESNO COUNTY NORTH...SHOWERS WILL PROBABLY BE OVER
NEAR OR BEFORE MIDNIGHT.
OVER THE SOUTH HALF OF THE CWA...IT MAY TAKE A LITTLE LONGER BUT
LIKELY TO BE OVER BEFORE SUNRISE. THE EXCEPTION BEING THE KERN
MTNS AND DESERTS...WHERE PRECIP MAY TAPER OFF A BIT THIS EVE...BUT
ACTUALLY PICK BACK UP AS THE LOW PASSES PT CONCEPTION AND UPPER
DEFORMATION/EASTERLY FLOW DEVELOPS. SNOWFALL THUS FAR HAS BEEN IN
THE 3-4 INCH RANGE IN THE CUDDY VALLEY/FRAZIER PARK AREA AND COULD
SEE AN ADDNL 4-6 BEFORE ALL IS SAID AND DONE. STILL HARD TO TELL
IF HEAVY SNOW WILL MAKE IT AS FAR EAST IN THE TEHACHAPIS AS
HIGHWAY 58. DEPENDS ON HOW MUCH UPSLOPE DEVELOPS ON THE EAST AND
SOUTH FACING SLOPES.
OTHERWISE ACROSS CENTRAL CA...A RATHER BENIGN PATTERN IS SEEN THE
REMAINDER OF THE WEEK AND THRU THE WEEKEND. AN UPPER LEVEL RIDGE
WILL GRADUALLY EXPAND OVER THE REGION...AND WHILE TEMPORARILY
BEING FLATTENED BY A COUPLE OF PAC NW SHORTWAVES...WILL HOLD ITS
GROUND INTO THE FIRST HALF OF NEXT WEEK. THUS LOOK FOR A WARMING
TREND TO BEGIN THURS AND CONT INTO THE WEEKEND. THE FLY IN THE
OINTMENT HOWEVER WILL BE HOW MUCH FOG DEVELOPS OR PERSISTS IN THE
VALLEY EACH NIGHT.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...VFR EXCEPT AREAS MVFR DUE TO LOWERING
CEILINGS AND VISIBILITY IN -RA/BR THROUGH 18Z WEDNESDAY...AFT 18Z
VFR THROUGH 00Z. OVER THE SIERRA NEVADA AND TEHACHAPI
MOUNTAINS...MVFR TO LCL LIFR DUE TO MOUNTAIN OBSCURATIONS IN CLOUDS
AND PRECIPITATION. IN THE KERN COUNTY DESERT...VFR EXCEPT LCL MVFR
IN SHRA POSSIBLY MIXED WITH -SN AFTER 04Z WEDNESDAY. ISOLATED TRW TIL
04Z WEDNESDAY.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM PST WEDNESDAY CAZ097.
WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY CAZ095.
&&
$$
PUBLIC...BINGHAM
AVN/FW...GREISS
SYNOPSIS...WP
WEATHER.GOV/HANFORD
000
FXUS66 KSGX 092239
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
240 PM PST TUE FEB 9 2010
.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM MOVING DOWN THE CALIFORNIA COAST WILL
TRACK SOUTHEAST ACROSS THE COASTAL WATERS TONIGHT. THE LOW IS
FORECAST TO TRACK EAST ACROSS NORTHERN BAJA CALIFORNIA EARLY
WEDNESDAY AND THEN MOVE EAST OF THE REGION BY WEDNESDAY EVENING.
THIS WILL BRING PERIODS OF PRECIPITATION THROUGH WEDNESDAY TO
SOUTHWEST CALIFORNIA WITH A CHANCE OF THUNDERSTORMS. SNOW LEVELS
WILL LOWER TO NEAR 3000 FEET LATE TONIGHT THROUGH EARLY WEDNESDAY.
DRY AND GRADUALLY WARMER THURSDAY THROUGH FRIDAY. STRONGER HIGH
PRESSURE THIS WEEKEND MAY BRING WARMING TO ABOVE SEASONAL AVERAGES
THROUGH TUESDAY AND WEAK OFFSHORE WINDS ARE POSSIBLE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.NEAR TERM...TONIGHT THROUGH WEDNESDAY MORNING...
STRONG COLD FRONT MOVING SOUTHEAST 22 KNOTS/25 MPH...ACROSS FORECAST
AREA TONIGHT. MODELS IN GOOD AGREEMENT ON STRENGTH AND TRACK OF
UPPER LOW...FORECAST TO BE CENTERED OVER SAN DIEGO BY 4 AM WEDNESDAY
AND CENTERED OVER NORTHERN GULF OF CALIFORNIA BY 4 PM WEDNESDAY.
COLD CORE...WITH 500 MB TEMPERATURES OF -30C AND 850 MB TEMPERATURES
-4C PASSING ACROSS SOUTHERN CALIFORNIA BIGHT AND RELATIVELY WARM
SEA SURFACE/925 MB TEMPERATURES WILL MAKE FOR VERY UNSTABLE LAPSE
RATES THROUGH EARLY WEDNESDAY MORNING. MAY HAVE SEVERE WEATHER
WATCHES OUT BEFORE THIS EVENT IS OVER.
&&
.REMAINDER SHORT TERM...WEDNESDAY AFTERNON THROUGH FRIDAY...
FOR WEDNESDAY AFTERNOON SLOW WINDING DOWN OF SHOWER ACTIVITY BUT
MADE SOME MINOR ADJUSTMENTS TO ENDING TIME OF PRECIPITATION EAST
SLOPES OF MOUNTAINS/LOWER DESERTS TO REFLECT WRAP AROUND
MOISTURE/OROGRAPHIC LIFTING STILL PRODUCING LIGHT SHOWERS INTO EARLY
EVENING HOURS WEDNESDAY. WEDNESDAY NIGHT THROUGH THURSDAY DRYING OUT
UNDER THE BUILDING HIGH PRESSURE RIDGE. MAY REINTRODUCE FROST FOR
INLAND VALLEYS WEDNESDAY NIGHT/THURSDAY MORNING AS WINDS FORECAST TO
GO TO NEAR CALM AND SKIES TO BE CLEAR. LOWER DESERT AREAS WILL
LIKELY STILL HAVE ENOUGH WIND TO KEEP FROST FROM FORMING THERE. FLAT
RIDGE FOR FRIDAY WITH TROUGH PASSING INLAND TO THE NORTH WILL ALLOW
MID/HIGH CLOUDS TO MOVE ACROSS THE FORECAST AREA.
&&
.LONG TERM...FRIDAY NIGHT THROUGH NEXT TUESDAY...
RIDGE REBUILDS SATURDAY AND SUNDAY CREATING A FAVORABLE PATTERN FOR
LIGHT TO MODERATE OFFSHORE WINDS. RIDGE FLATTENS SOMEWHAT MONDAY AND
TUESDAY AS TROUGHS PASS INLAND WELL TO THE NORTH.
&&
.AVIATION...
092000Z...COLD FRONT APPROACHING FROM THE NORTHWEST IS EXPECTED TO
MOVE THROUGH THIS AFTERNOON AND EVENING. THE LEADING EDGE WAS
ALREADY MOVING INTO THE KSNA/KONT AREA AND SHOULD REACH KSAN BY 21Z.
THE MAIN FRONT SHOULD FOLLOW WITHIN AN HOUR OR TWO. EXPECT MOSTLY
OVERCAST LAYERS OF STRATOCU/CU AND ISOLATED CBS WITH BASES BETWEEN
FL015 AND FL030 THROUGH THE AFTERNOON AND EARLY EVENING.
VISIBILITIES MOSTLY 3 TO 5 MILES IN SHOWERS EXCEPT LOCALLY 1 MILE IN
MODERATE TO HEAVY SHOWERS/TSTMS. BEHIND THE FRONT AND CONTINUING
THROUGH THE NIGHT INTO WEDNESDAY MORNING...MOSTLY BROKEN CU/TCU WITH
BASES BETWEEN 2000 AND 3000 FEET AND TOPS TO 10000 FEET MSL EXCEPT
TOPS TO FL250 IN ISOLATED TSTMS. MOUNTAINS WILL BE MOSTLY OBSCURED
THROUGH WEDNESDAY MORNING. BECOMING MOSTLY SCATTERED CONDITIONS BY
WEDNESDAY AFTERNOON. HORTON
&&
.MARINE...
WATERSPOUTS HAVE BEEN REPORTED TODAY AND POTENTIAL EXISTS FOR
ADDITIONAL WATERSPOUTS TO DEVELOP THROUGH WEDNESDAY MORNING. SEE
SPECIAL MARINE WARNINGS AND MARINE WEATHER STATEMENT.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WINTER WEATHER ADVISORY BELOW 4500 FEET UNTIL 6 AM PST
WEDNESDAY FOR SAN BERNARDINO COUNTY MOUNTAINS-RIVERSIDE COUNTY
MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY ABOVE 3000 FEET UNTIL 6 AM PST
WEDNESDAY FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-
SAN DIEGO COUNTY DESERTS-SANTA ANA MOUNTAINS AND FOOTHILLS.
FLASH FLOOD WATCH THROUGH 6 AM PST WEDNESDAY FOR ORANGE
COUNTY COASTAL AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY
VALLEYS-THE INLAND EMPIRE-SANTA ANA MOUNTAINS AND FOOTHILLS.
WINTER STORM WARNING ABOVE 4500 FEET UNTIL 6 AM PST WEDNESDAY
FOR RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-
SAN DIEGO COUNTY MOUNTAINS.
SPECIAL WEATHER STATEMENT TO SUMMARIZE ABOVE AND COVER OTHER
EFFECTS IN REMAINING ZONES.
PZ...MARINE WEATHER STATEMENT BOTH INNER AND OUTER COASTAL
WATERS FOR THREAT OF THUNDERSTORMS AND WATERSPOUTS THROUGH
WEDNESDAY MORNING.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KMTR 092235 AAA
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
235 PM PST TUE FEB 9 2010
.DISCUSSION...AS OF 2:35 PM PST TUESDAY...RAIN ENDING THIS EVENING.
DRY ON WEDNESDAY FOLLOWED BY SOME RAIN FOR LATE THURSDAY INTO
FRIDAY. QUIET WEATHER NEXT WEEK.
FAIRLY DRAMATIC SATELLITE DEPICTION OF A SHARP TROUGH AND
ASSOCIATED LOW THAT IS CURRENTLY DIVING SOUTHWARD ALONG THE COAST.
AS OF 2 PM...THE LOW CENTER WAS LOCATED ABOUT 100 MILES WSW OF
MONTEREY AND CONTINUING TO MOVE TO THE SSE AROUND 20 KT. BANDS OF
SHOWERS HAVE BEEN ROTATING AROUND THE LOW THROUGH THE DAY TODAY. 6
HOUR PRECIP TOTALS FROM THE MORNING INTO THE EARLY AFTERNOON ARE
UNIMPRESSIVE WITH THE BULK SITUATED SOUTH OF SF BAY. VALUES RANGE
FROM JUST A FEW HUNDREDTHS AROUND SF BAY INTO THE SANTA CLARA VALLEY
WITH .1 TO .3" FOR COASTAL SPOTS TO THE SOUTH. SEVERAL SPOTTERS WERE
CONTACTED AND ONLY MINOR SNOW ACCUMULATIONS WERE NOTED DESPITE THE
FACT THAT TEMPERATURES AS LOW AS 3000 FEET DID DROP TO FREEZING
DURING A PORTION OF THE MORNING.
SHOWERS WILL CONTINUE TO MOVE TO THE SOUTH AS THE LOW DIVES FURTHER
DOWN THE COAST. THE BEST CHANCE FOR PRECIPITATION WILL BE FOR SPOTS
OVER THE SOUTHERN THIRD OF THE CWA THIS EVENING ESPECIALLY HIGHER
ELEVATIONS LOCATIONS AND AT THE COAST. LITTLE SNOW ACCUMULATION IS
NOW EXPECTED FOR LOCATIONS UNDER 3000 FEET. FOR ABOVE 3000 FEET...1-
3 INCHES ARE STILL POSSIBLE THROUGH THE EVENING WITH THE BEST CHANCE
FOR THE SANTA LUCIA RANGE. CLOUDS WILL BEGIN TO CLEAR OUT ACROSS MUCH
OF THE CWA TONIGHT WHICH WILL ALLOW TEMPERATURES TO DROP INTO THE 30S
AND 40S. PATCHY FOG AND FROST IS POSSIBLE OVER THE NORTH BAY VALLEYS
WITH SOME POCKETS OF FOG OVER THE EAST BAY.
AFTER A BREAK IN THE WEATHER WEDNESDAY...CLOUDS WILL START TO
RETURN ON THURSDAY IN ADVANCE OF A COLD FRONT. PRECIPITATION WILL
SPREAD FROM NORTH TO SOUTH AS TWO TROUGHS MOVE ACROSS THURSDAY NIGHT
INTO FRIDAY NIGHT. MODEL TRENDS CONTINUE TO DOWNPLAY THIS EVENT AND
ARE TRENDING TO MORE OF A NORTHERLY SOLUTION. IN FACT...IF THE
ECMWF OPERATIONAL RUN VERIFIES...FRIDAY WILL BE MOSTLY DRY AREA
WIDE. HPC CURRENTLY BRINGS AROUND 1/4" TO SF BAY NORTHWARD WITH ONLY
AROUND 1/10" FURTHER SOUTH. THIS SEEMS REASONABLE GIVEN THERE IS
STILL SOME UNCERTAINTY WITH HOW FAR NORTH BOTH TROUGHS WILL BE.
FOR SATURDAY THROUGH NEXT WEEK WE WILL LIKELY ENTER A MUCH QUIETER
WEATHER PERIOD WITH NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES AS
A RIDGE BUILDS OVER THE WESTERN CONUS. BOTH GFS (MODERATE SPREAD) AND
ECMWF ENSEMBLES (SMALL SPREAD) FAVOR THIS SOLUTION AS WELL. IF IT
PANS OUT IT WOULD KEEP ALL MAJOR STORMS OUT OF OUR AREA.
&&
.AVIATION...AS OF 10:00 AM TUESDAY...UNSETTLED WEATHER TODAY AS THE
COLD CORE UPPER LOW REMAINS OVERHEAD. SHOWER ACTIVITY WILL BE HIT
OR MISS...BUT IT DOES APPEAR THAT THE BEST INSTABILITY WILL BE JUST
OFFSHORE. THAT BEING SAID...HAVE DECREASED SHOWERS FOR LOCATIONS N
OF KSJC. SKIES WILL CLEAR ON THE BACKSIDE OF THE LOW LATER TODAY.
VALLEY FOG WILL LIKELY DEVELOP TONIGHT AT KSTS.
VICINITY OF KSFO...UPDATED FOR MORE SOUTHEAST FLOW AS THE UPPER LOW
HANGS TO THE WEST. HAVE ALSO WENT MORE VCSH AS MUCH OF THE SHOWER
ACTIVITY IS TO THE SOUTH AND WEST OF THE AIRPORT. THAT IS NOT TO
SAY A ROGUE SHOWER WILL NOT PASS OVERHEAD.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...SHOWERS WILL PREVAIL THROUGH THE
AFTERNOON...DEVELOPING OFFSHORE AND GRADUALLY DRIFTING ONSHORE.
CIGS MAY BRIEFLY LOWER WITH THESE SHOWERS. CLEAR LATER TODAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: MM
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
[top]
000
FXUS65 KREV 092228
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
228 PM PST TUE FEB 9 2010
.SHORT TERM...
UPPER LOW DROPPING SOUTH OF MONTEREY BAY THIS AFTERNOON AS
SCHEDULED. LIGHT SNOW/RAIN SHOWERS IN THE WRAP AROUND MOISTURE AND
DEFORMATION ZONE ON THE NORTHEAST SIDE OF THE LOW HAS CONTINUED
MUCH OF TODAY SOUTH OF I-80. SNOW LEVELS HAVE BEEN ABLE TO RISE
TO 4000-4500 FEET...BUT WILL NOT GO HIGHER AS TEMPERATURE
STRUGGLES TO REACH 40 THIS AFTERNOON DUE TO CLOUD COVER. ANY RISE
IN SNOW LEVEL WILL DROP BACK DOWN TO VALLEY FLOORS SHORTLY AFTER
SUNSET.
MAIN ISSUE THIS EVENING IS IF THE DEPTH OF THE MOISTURE AND LOW
LEVEL EAST-NORTHEAST FLOW WILL PROVIDE UPSLOPE ENHANCEMENT THE
PRECIPITATION BAND SOUTH OF US-50 THIS EVENING. WITH THE LOW
CENTER ABOUT 50 MILES OFF SHORE...THE COLD CORE IS TOO FAR AWAY TO
BRING A MID AND UPPER LEVEL INSTABILITY BOOST. SO THINKING UPSLOPE
ENHANCEMENT WILL BE MINIMAL...BUT GOOD CONFIDENCE LIGHT SNOW WILL
AFFECT DOUGLAS...ALPINE...MONO...SOUTHERN LYON AND MINERAL THIS
EVENING. SNOW MAY LINGER PAST MIDNIGHT FOR SOUTHERN MONO/MINERAL
AS MOISTURE QUICKLY RECEDES TO THE SOUTH. ANY ACCUMULATIONS THIS
EVENING WILL BE LIGHT...LESS THAN 2 INCHES.
RIDGE WILL BUILD OVER THE AREA WEDNESDAY AFTERNOON WITH A FEW
DEGREES OF WARMING AHEAD OF THE NEXT TWO WAVES. LAST NIGHT/S
RUNS AND 12Z RUNS THIS MORNING HAVE KEPT THE BULK OF THE MOISTURE
AND ENERGY WELL NORTH OF THE AREA UNTIL FRIDAY AFTERNOON. TRENDED
TO A MUCH DRIER FORECAST THURSDAY-FRIDAY FOR MOST AREAS.
LIGHT WARM AIR ADVECTION IS POSSIBLE NORTHERN LASSEN AND WASHOE
COUNTIES LATE WEDNESDAY NIGHT AND THURSDAY...WITH DRY CONDITIONS
ELSEWHERE. MOISTURE STARTS TO INCREASE THURSDAY NIGHT NORTH OF
I-80 BUT WITH LACK OF LIFT CUT BACK POPS MOST AREAS AND LEFT
CHANCE FOR RAIN/SNOW FOR LASSEN/PLUMAS/SIERRA COUNTIES.
BY FRIDAY WINDS ALOFT INCREASE AND MOISTURE BANKS UP AGAINST THE
WEST SLOPES AS THE SECOND WAVE PASSES INTO SOUTHERN OREGON. MODELS
MAINTAIN LIGHT QPF AMOUNTS FOR THE NORTHERN SIERRA...SO LIMITED
THE POPS TO THAT AREA. DECENT AMOUNT OF SHADOWING AND 700MB WINDS
OF 40-50KTS...WITH INCREASING SURFACE GRADIENT COULD BRING BREEZY
AND WARM CONDITIONS TO THE EAST SLOPES AND WESTERN NEVADA. BRONG
.LONG TERM...SATURDAY THROUGH TUESDAY...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE WEST FOLLOWING THE SYSTEM
ON FRIDAY. THIS RIDGE IS PROGGED TO DOMINATE THE WEATHER PATTERN
THROUGH THE ENTIRE EXTENDED PERIOD.
A SERIES OF SHORTWAVES WILL RIDE OVER THE TOP OF THE RIDGE
THROUGHOUT THE WEEK...BUT THE MAIN EFFECT OF THESE WILL ONLY BE SOME
HIGH CLOUDS. REMOVED MENTIONABLE POPS THROUGHOUT THE WEEK AS ALL
MODELS ARE KEEPING THE WAVES NORTH OF THE CWA. THOUGH...HAVE KEPT
SLIGHT CHANCE POPS IN THE FORECAST THROUGH NORTHERN LASSEN AND
EXTREME NORTHERN WASHOE COUNTIES WHICH WILL BE CLOSEST TO THE
MOISTURE.
TEMPERATURES WILL BE ON THE INCREASE...GENERALLY REACHING 3 TO 6
DEGREES ABOVE NORMAL ACROSS THE SIERRA AND WESTERN NV SUNDAY THROUGH
TUESDAY. AT THIS POINT IT DOES NOT APPEAR THERE WILL BE ANY STRONG
INVERSIONS PRESENT AND SO THE WARMING POTENTIAL SHOULD BE REALIZED.
DF
&&
.AVIATION...
SNOW SHOWERS WILL CONTINUE ACROSS THE SIERRA AND WESTERN NV THROUGH
LATE THIS AFTERNOON. THESE WILL TAPER OFF FROM THE NORTH TO THE
SOUTH...MAINLY LINGERING ONLY THROUGH MONO AND MINERAL COUNTIES THIS
EVENING. AM NOT EXPECTING SIGNIFICANT REDUCTIONS TO VISIBILITY DUE
TO THE SNOW...BUT CIGS MAY DROP BETWEEN 010-025...WHICH WILL OBSCURE
THE TERRAIN.
FOR KRNO...SNOW SHOWERS ARE POSSIBLE IN THE AIRPORT VICINITY THROUGH
ABOUT 00Z THIS EVENING...BUT SNOW ACCUMULATION IS HIGHLY UNLIKELY.
MAIN IMPACTS WILL BE THE MVFR CIGS AND MOUNTAIN OBSCURATION...THESE
SHOULD IMPROVE BETWEEN 00-02Z THIS EVENING.
FOR KTRK AND KTVL...SNOW SHOWERS ARE POSSIBLE AROUND TAHOE THROUGH
ABOUT 01Z THIS EVENING...WITH LITTLE TO NO NEW SNOW ACCUMULATION
EXPECTED. IFR-MVFR CIGS WILL LINGER THROUGH THIS EVENING CAUSING
MOUNTAIN OBSCURATION. THERE IS A 60 PERCENT CHANCE THAT FOG WILL
DEVELOP OVERNIGHT AT BOTH AIRPORTS. DF
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS65 KPSR 092217
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 PM MST TUE FEB 9 2010
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL BRING RAIN AND MOUNTAIN SNOW SHOWERS...
AS WELL AS A SLIGHT CHANCE OF THUNDERSTORMS...OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT INTO EARLY
WEDNESDAY...AND MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA
WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL
THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN
RATHER COOL. DRY AND WARMER WEATHER WILL COMMENCE FRIDAY AND
CONTINUE THROUGH EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE BECOMES
ESTABLISHED OVER THE WESTERN UNITED STATES. TEMPERATURES WILL BE
SEVERAL DEGREES ABOVE NORMAL SATURDAY THROUGH AT LEAST NEXT TUESDAY.
&&
.DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED SW OF SAN FRANCISCO AS OF 21Z (2 PM MST)...AND
CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS. AS MENTIONED
THIS MORNING...NUMERICAL MODELS ARE IN GOOD AGREEMENT REGARDING
TRACK OF THIS LOW...KEEPING IT ON A PATH THAT PARALLELS THE
CALIFORNIA COAST DURING THE NEXT 18 HRS...PLACING IT JUST WEST OF
SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT SLOWLY EAST ALONG THE
INTERNATIONAL BORDER TO JUST SOUTH OF THE ARIZONA-NEW MEXICO BORDER
BY 12Z THURSDAY. AS SUCH...STRONGEST FORCING/UVV AND BEST CHANCE FOR
PRECIPITATION WILL TRACK ACROSS FAR SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TONIGHT...ACROSS SOUTHERN QUARTER OF ARIZONA ON
WEDNESDAY...AND OVER SOUTHEAST ARIZONA WEDNESDAY NIGHT (PRINCIPAL
UPPER SUPPORT AND BEST CHANCE FOR PRECIPITATION DOES AN `END RUN`
AROUND SOUTH-CENTRAL ARIZONA). GIVEN ONLY MODEST MOISTURE
AVAILABILITY AS WELL AS THE FACT THE STORM WILL TRACK WELL SOUTH OF
OUR FORECAST AREA...PRECIP TOTALS FROM THIS STORM WILL BE RATHER
MODEST...LESS THAN ONE HALF INCH AT MOST LOCALES. TOTALS IN EXCESS
OF ONE THIRD INCH...BUT LESS THAN ONE HALF INCH...WILL BE MOST
LIKELY OVER FAR SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA TONIGHT
INTO WEDNESDAY MORNING...AND OVER THE HIGHER TERRAIN OF SOUTH-
CENTRAL ARIZONA WEDNESDAY NIGHT. PRECIP AMOUNTS WILL VARY QUITE A
BIT FROM SITE TO SITE...SINCE CONVECTIVE SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED. STRONG RIDGING DEVELOPS BEHIND THE LOW
THURSDAY WHICH WILL QUICKLY BRING THE THREAT OF PRECIP TO AN END.
GFS/ECMWF IN GOOD AGREEMENT THAT A MUCH DIFFERENT AND RATHER
PERSISTENT LONG WAVE PATTERN WILL BECOME ESTABLISHED THIS WEEKEND
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. RIDGE AXIS SETS UP NEAR
120W (FAR WESTERN UNITED STATES) WHILE BROAD TROUGH WILL BE CENTERED
NEAR 90W (EASTERN UNITED STATES). THIS PATTERN PROMISES TO BRING DRY
CONDITIONS WITH DAYTIME HIGHS SEVERAL DEGREES ABOVE NORMAL THIS
WEEKEND INTO EARLY NEXT WEEK...WITH WARMEST DAYTIME HIGHS TOWARD THE
END OF THIS FORECAST PACKAGE (EARLY NEXT WEEK).
&&
.AVIATION...
KPHX AND KIWA...
SFC WINDS FROM THE SOUTH/SOUTHEAST SLOWLY INCREASING ACROSS THE
PHOENIX AREA THIS AFTN. FAIR CONFIDENCE WINDS WILL REMAIN FROM
THE SOUTH TONIGHT...AHEAD OF THE DEEP UPPER LOW IN CALIF.
ALSO...CLOUDS AT/ABOVE 15 THSD FT ON THE INCREASE...WITH PRECIP
SPREADING FROM WEST TO EAST AFT 10/12Z. BY 10/15Z THE LOWER
CIGS...8-10 THSD FT WILL FILTER INTO THE METRO AREA ALONG WITH LGT
RAIN.
KIPL AND KBLH...
NORTH-SOUTH LINE OF LGT SHOWERS WITH CIGS 6-8 THSD FT WILL BRUSH
ACROSS CALIF DESERTS THRU 10/00Z. ADDITIONAL SHOWERS LIKELY TO BRING
BEST CHANCE OF SHOWERS AFT DARK AT BOTH KIPL/KBLH. GOOD CONFIDENCE
THAT LOWER VSBYS WILL ACCOMPANY THE PRECIP AND CIGS...AND 5-7 MILES
VSBYS STILL LOOK GOOD. GUSTY WINDS ALSO MAY REACH 20-25 KTS SPCLY
ASSOCD WITH ISOLD TSTMS. TIMING OF CLEARING TREND STILL GOOD BY WED
AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
[top]
000
FXUS66 KEKA 092159
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
159 PM PST TUE FEB 9 2010
.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD OVER THE NORTH STATE
TONIGHT BRINGING DRY WEATHER WITH PATCHY VALLEY FOG. A WEAK FRONT
WILL APPROACH THE REGION LATE TOMORROW...POSSIBLY BRINGING A FEW
SPRINKLES OR LIGHT SHOWERS. A SERIES OF SYSTEMS WILL IMPACT THE
REGION THROUGH THE END OF THE WEEK.
&&
.DISCUSSION...THE MAIN FORECAST CHALLENGES ARE PRECIPITATION
CHANCES/AMOUNTS LATE WEDNESDAY THROUGH THE END OF THE WEEK.
VERTICALLY STACKED LOW PRESSURE CURRENTLY WEST OF THE MONTEREY/SLO
COUNTY COAST WILL CONTINUE TO MOVE AWAY FROM THE AREA OVERNIGHT
LEAVING DRY WEATHER AND (MAINLY) CLEAR SKIES. VALLEY FOG WILL
DEVELOP OVERNIGHT AND SOME HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM
WILL GRADUALLY SPILL INTO THE AREA FROM THE WEST. WHILE SOME PATCHY
FROST CANNOT BE RULED OUT ALONG THE COAST...MOST PLACES WILL SETTLE
IN THE UPPER 30S SO IT WILL NOT BE A WIDESPREAD/SEVERE ISSUE.
A WARM FRONTAL SYSTEM WILL BRING INCREASING MID AND HIGH LEVEL
CLOUDINESS TO THE REGION DURING THE DAY WEDNESDAY. SPRINKLES OR
LIGHT SHOWERS MAY DEVELOP DURING THE AFTERNOON ALONG THE COAST NORTH
OF THE CAPE...BUT THESE SHOULDN`T BE MUCH. WEDNESDAY NIGHT WILL OFFER
UP A BETTER THREAT FOR RAIN BUT EVEN THEN AMOUNTS WILL PROBABLY BE
A TENTH OF AN INCH OR LESS FOR MOST AREAS. SOME TIMING DIFFERENCES
PERSIST BETWEEN COMPETING MODELS...BUT THERE IS SOME INDICATION
THAT WE MAY HAVE A SIZABLE BREAK IN PRECIP BETWEEN LATE WEDNESDAY
NIGHT AND THURSDAY AFTERNOON WHEN THE COLD FRONT APPROACHES. OPTED
NOT TO MONKEY AROUND WITH THE INHERITED FORECAST`S POPS GIVEN
THESE DIFFERENCES BUT THIS MAY NEED TO BE BETTER REFINED GIVEN THE
POTENTIAL 12-18 HOUR WINDOW OF LITTLE OR NO RAIN. ANOTHER SOMEWHAT
STRONGER FRONT WILL AFFECT US ON FRIDAY.
THE PATTERN TRANSITION IS A LITTLE MORE AMBIGUOUS THEREAFTER. THE 5
WAVE SHOWS THE COLD CORE LOW OVER THE RUSSIAN FAR EAST RETREATING
WEST INTO SIBERIA...WHICH MAY ALLOW RIDGING TO DEVELOP ACROSS THE WEST
FOR MUCH OF NEXT WEEK. RIGHT NOW...WE HAVE TAKEN A MIDDLE OF THE
ROAD APPROACH WHICH ESSENTIALLY SUPPORTS THE THREAT OF WEAK
SYSTEMS BRUSHING UP AGAINST THIS RIDGE WITH PERIODIC CHANCES (AT
OR BELOW CLIMATOLOGY) FOR RAIN BUT NO MAJOR STORMS. BURGER
&&
.AVIATION...HIGH CLOUDS WILL MOVE ACROSS THE REGION TONIGHT AS
WEAK HIGH PRESSURE MOVES OVER THE REGION. THE HIGH CLOUDS WILL BE
SLOWER TO REACH MENDOCINO COUNTY...WITH CLEAR SKIES PREVAILING MOST
THE NIGHT. PATCHY FOG MAY DEVELOP IN INTERIOR VALLEYS
OVERNIGHT...ESPECIALLY ACROSS MENDOCINO COUNTY WHERE CLEARING AND
LINGERING SURFACE MOISTURE WILL BE MORE ABUNDANT. TH
&&
.MARINE...MAIN MARINE IMPACTS THIS WEEK ARE INCREASING WINDS AND
SWELL LATE IN THE WEEK. MODELS ARE FAIRLY CONSISTENT THAT SOUTH
WINDS WILL DEVELOP WED AFTERNOON AS WEAK FRONT APPROACHES NW CA. THE
SURFACE PRESSURE GRADIENT WILL TIGHTEN AS THE FRONT CLIPS THE
NORTHERN WATERS WED NIGHT...AND TIGHTEN EVEN MORE THU MORNING WHEN A
STRONGER FRONT WILL NEAR THE WATERS. THE DIFFERENT MODELS VARY ON
THE POSITION AND STRENGTH OF THE LOW ASSOCIATED WITH THIS
FRONT...BUT ALL SUGGEST THE POTENTIAL FOR GALES THU...ESPECIALLY
NORTH OF CAPE MENDOCINO. CONFIDENCE IS HIGHER FOR GALES ACROSS THE
NORTHERN OUTER WATERS...WHERE A GALE WATCH HAS BEEN ISSUED. THESE
STORMS WILL ALSO GENERATE A LARGE LONG PERIOD NW SWELL LATE THU
NIGHT AND FRI..HAVE GONE A COUPLE OF FEET BELOW GUIDANCE DUE TO THE
VARIABILITY OF MODELS ON THE LOW. TH
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...GALE WATCH FROM THURSDAY
MORNING THROUGH THURSDAY EVENING PZZ470.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KLOX 092158
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PST TUE FEB 9 2010
.SYNOPSIS...
A COLD STORM SYSTEM WILL BRING SHOWERS AND LOW ELEVATION
SNOW...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS TODAY INTO EARLY
WEDNESDAY. DRY WEATHER EXPECTED THE REST OF THE WEEK WITH DAYTIME
HIGHS RISING TO WELL ABOVE NORMAL FOR THE WEEKEND.
&&
.SHORT TERM (TODAY-FRI)...UPPER LOW JUST OFF THE MONTEREY COUNTY
COAST, THE CENTER OF WHICH IS JUST WEST OF MODEL INITIALIZATIONS.
THE FIRST BAND OF SHOWERS MOVED THROUGH THIS MORNING THROUGH EARLY
AFTERNOON AND BROUGHT PERIODS OF HEAVY RAIN AND SCATTERED
THUNDERSTORMS. DECENT UPPER LEVEL DIVERGENCE IS HELPING TO ENHANCE
PRECIPITATION RATES, ESPECIALLY OVER LA COUNTY THIS AFTERNOON WITH
THIS EXPECTED TO CONTINUE THROUGH THE EARLY EVENING HOURS. LOCAL
MODELS INDICATE THE POTENTIAL FOR RAINFALL RATES TO EXCEED A HALF
INCH PER HOUR, ESPECIALLY IN LA COUNTY THROUGH THE EARLY EVENING SO
FLASH FLOOD WATCH LOOKS GOOD FOR THE BURN AREAS.
A SECOND AREA OF SHOWERS IS MOVING INTO THE CENTRAL COAST THIS
AFTERNOON JUST AHEAD OF THE COLD CORE LOW. A LITTLE SURPRISED THAT
LIGHTNING ACTIVITY HAS BEEN SO MINIMAL WITH THE LOW CENTER BUT I
EXPECT AS IT MOVES SOUTH OVER WARMER WATERS AND A MORE UNSTABLE
AIRMASS OVERALL CONVECTIVE ACTIVITY WILL INCREASE. HOWEVER, LATEST
MODELS TRENDED FURTHER WEST WITH THE TRACK OF THE LOW CENTER,
HINTING THAT THE BULK OF THE HEAVIER RAIN WITH THE CORE LOW WILL
REMAIN OFFSHORE WITH JUST SCATTERED SHOWERS OVER LAND. BASED ON
THESE TRENDS POPS WERE SCALED BACK A BIT OVER LAND AND ESPECIALLY
NORTH OF PT CONCEPTION AFTER MIDNIGHT AS THE LOW PASSES TO THE
SOUTH.
ON WEDNESDAY LOW LVL FLOW SHIFTS TO THE NORTHEAST AS THE UPPER LOW
MOVES SOUTHWEST OF THE AREA. MOISTURE IS LIMITED BUT POSSIBLY ENOUGH
TO GENERATE SOME NORTH FACING SLOPE AND ANTELOPE VALLEY SHOWER
ACTIVITY THROUGH WEDNESDAY AFTERNOON. OTHERWISE, CLOUDS AND SHOWERS
WILL BE ENDING EARLY WED MORNING WITH A DRY BUT COOL DAY EXPECTED.
DRY WEATHER TO CONTINUE THROUGH FRIDAY AS MODELS INDICATE THE LATE
WEEK SYSTEM WILL PRETTY MUCH BE A NON-ISSUE NOW. MAYBE JUST SOME
INCREASE IN CLOUDS FOR AREAS NORTH OF PT CONCEPTION FRIDAY.
OTHERWISE, DAYTIME HIGHS WILL BE WARMING UP TO NEAR NORMAL LEVELS BY
FRIDAY AND POSSIBLY SLIGHTLY ABOVE NORMAL.
.LONG TERM (SAT-TUE)...DRY PATTERN THROUGH EARLY NEXT WEEK WITH WEAK
TO MODERATE OFFSHORE FLOW AND 950 TEMPS AROUND 20C. THIS TYPICALLY
PRODUCES HIGHS IN THE MID 70S AT LEAST ACROSS LOWER ELEVATIONS SOUTH
OF PT CONCEPTION AND NEAR 70 IN THE NORTH. WOULD NOT BE SURPRISED TO
SEE SOME AREAS NEAR 80 SUNDAY AND MONDAY.
&&
.AVIATION...09/1915Z.
SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH A VERY COLD UPPER
LEVEL LOW DROPPING SOUTH ALONG THE COAST WILL CONTINUE INTO THIS
EVENING. THERE WILL BE MVFR TO LOCAL IFR CONDITIONS IN BRIEF HEAVY
RAIN. VFR CONDITIONS WILL AGAIN BECOME MORE PREVALENT LATE THIS
EVENING AND TONIGHT.
KLAX...GOOD CONFIDENCE IN MVFR TO IFR CONDITIONS IN BRIEF HEAVY RAIN
AND SMALL HAIL. ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE. THE
ACTIVITY WILL DIE DOWN LATER THIS EVENING AND OVERNIGHT.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...WOFFORD
AVIATION...SWEET
SYNOPSIS...BARTLING
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 092117 AAB
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 PM MST TUE FEB 9 2010
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
EXPECT AN INCREASE IN CLOUDINESS MAINLY OVER FAR SOUTHEASTERN
CALIFORNIA AND WEST-CENTRAL ARIZONA TODAY AS A LOW PRESSURE SYSTEM
APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW SHOWERS...AS
WELL AS A SLIGHT CHANCE OF A THUNDERSTORM...WILL OCCUR OVER FAR
SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT
INTO EARLY WEDNESDAY...THEN MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL
ARIZONA WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL
PREVAIL THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL
REMAIN RATHER COOL. WARMER WEATHER WILL SLOWLY RETURN HEADING INTO
THE WEEKEND...WITH ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED JUST SW OF SAN FRANCISCO AS OF 17Z (10AM
MST)...AND CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS.
MODELS IN GOOD AGREEMENT REGARDING TRACK OF THIS LOW...KEEPING IT ON
A PATH THAT PARALLELS THE CALIFORNIA COAST DURING THE NEXT 24 HRS...
PLACING IT JUST WEST OF SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT
TO JUST SOUTH AND WEST OF ORGAN PIPE NM BY 00Z THURSDAY. ADJUSTED
POP/QPF/SKY GRIDS TO BETTER REFLECT THE STORM TRACK...WHICH...AS
MIDSHIFT NOTES...WILL BE A LITTLE BIT TO THE SOUTH AND WEST OF WHAT
WAS PREVIOUSLY EXPECTED. AS SUCH...PRECIPITATION WILL BE MOST LIKELY
OVER FAR SE CALIFORNIA/SW AZ TONIGHT (WINTER WX ADVISORY FOR THE
JOSHUA TREE NATIONAL PARK LOOKS GOOD)...OVER SOUTHWEST AND EXTREME
SOUTH-CENTRAL AZ (SOUTH OF METRO PHOENIX) WEDNESDAY...AND OVER THE
HIGHER TERRAIN OF SOUTH-CENTRAL AZ (SOME SNOW ACCUMULATION EXPECTED
AT AND ABOVE 4000 FEET...REFER TO THE HAZARDOUS WEATHER OUTLOOK FOR
MORE DETAILS) AND SOUTHEAST ARIZONA WEDNESDAY NIGHT. AS THINGS NOW
STAND...PRECIP TOTALS FROM THIS STORM WILL BE ONLY ONE TO TWO TENTHS
OF AN INCH OVER SOUTH-CENTRAL AZ...ONE QUARTER TO ONE THIRD INCH
OVER FAR SOUTHEAST CALIFORNIA SOUTHWEST ARIZONA...AND ABOUT ONE
THIRD INCH OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL AZ.
.PREVIOUS DISCUSSION...
IT NOW APPEARS THE STRONGEST FORCING WILL IMPACT OUR WRN CWA...THEN
SWING SOUTH AND EAST OF OUR AREA. OVERALL SYSTEM REMAINS VERY
IMPRESSIVE WITH IT/S FORCING FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE IN SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S ON THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
KPHX AND KIWA...
SFC WINDS FROM THE SOUTH/SOUTHEAST SLOWLY INCREASING ACROSS THE
PHOENIX AREA THIS AFTN. FAIR CONFIDENCE WINDS WILL REMAIN FROM
THE SOUTH TONIGHT...AHEAD OF THE DEEP UPPER LOW IN CALIF.
ALSO...CLOUDS AT/ABOVE 15 THSD FT ON THE INCREASE...WITH PRECIP
SPREADING FROM WEST TO EAST AFT 10/12Z. BY 10/15Z THE LOWER
CIGS...8-10 THSD FT WILL FILTER INTO THE METRO AREA ALONG WITH LGT
RAIN.
KIPL AND KBLH...
NORTH-SOUTH LINE OF LGT SHOWERS WITH CIGS 6-8 THSD FT WILL BRUSH
ACROSS CALIF DESERTS THRU 10/00Z. ADDITIONAL SHOWERS LIKELY TO BRING
BEST CHANCE OF SHOWERS AFT DARK AT BOTH KIPL/KBLH. GOOD CONFIDENCE
THAT LOWER VSBYS WILL ACCOMPANY THE PRECIP AND CIGS...AND 5-7 MILES
VSBYS STILL LOOK GOOD. GUSTY WINDS ALSO MAY REACH 20-25 KTS SPCLY
ASSOCD WITH ISOLD TSTMS. TIMING OF CLEARING TREND STILL GOOD BY WED
AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
000
FXUS66 KLOX 091937
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1130 AM PST TUE FEB 9 2010
NEW AVIATION DISCUSSION
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TODAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOL TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK.
&&
.SHORT TERM (TODAY-THU)...
A COLD WOBBLY LOW JUST WEST OF THE BAY AREA WILL MOVES SOUTHWARD
TODAY. IT WILL BRING SHOWERS TO THE AREA TODAY...OVERNIGHT AND INTO
WEDNESDAY MORNING BEFORE EXITING THE REGION. THIS KIND OF SYSTEM IS
VERY TRICKY TO FORECAST AS ONLY SLIGHT VARIATION IN THE STORM TRACK
PRODUCE LARGE CHANGES IN THE AMOUNT OF RAINFALL. THE MDLS ARE ALSO
HAVING SOME PROBLEMS WITH THE EXACT TRACK WITH LAST NIGHTS MDLS
INLAND...YDYS RUNS SHOWING A LITTLE MORE OFFSHORE...LAST EVENINGS
RUNS WERE VERY WET WITH A GOOD OFFSHORE TRACK...AND NOW THE LATEST
RUNS ARE SHOWING A DRIER MORE INLAND PATH. THESE DIFFERENCES WILL
NOT AFFECT WEATHER OR NOT IT WILL RAIN OR NOT...JUST THE AMOUNT OF
RAIN. THE MOST INTERESTING ASPECT OF TODAYS SYSTEM IS HOW THE COLD
AIR ALOFT AND THE DIFFLUENT JET DYNAMICS WILL CONSPIRE TO PRODUCE
BOTH THERMODYNAMIC AND DYNAMIC CONVECTIVE INSTABILITY. THERE HAVE
ALREADY BEEN LIGHTNING STRIKES OFFSHORE IN THE COLD CORE OF THE LOW
AND A SLIGHT CHANCE OF TSTMS WILL OCCUR THIS AFTERNOON AND
OVERNIGHT. THE BEST CHANCE OF THE TSTMS WILL OCCUR WHEN THE CORE OR
LOW IS CLOSEST TO ANY GIVEN AREA.
THE SYSTEM SEEMS TO MOVING A LITTLE FASTER THAN CURRENT MDLS
ADVERTISE WITH SOME SHOWERS JUST NOW APPROACHING THE NORTHWEST TIP
OF SLO COUNTY. LOOK FOR RAIN AND A SLIGHT CHC OF TSTMS TO DEVELOP
OVER THE CENTRAL COAST THIS MORNING AND THEN THE SHOWERS AND SLGT
CHC OF TSTMS WILL SPREAD INTO VTA AND LA COUNTIES THIS AFTERNOON.
RAIN WILL TAPER OFF OVER THE CENTRAL COAST LATER THIS EVENING AND
END OVERNIGHT WHILE SOUTH OF POINT CONCEPTION THE SHOWERS WILL TAPER
OFF AFTER MIDNIGHT AND END WEDNESDAY MORNING.
THIS WILL BE A COLD SYSTEM WILL LOW SNOW LEVELS...BUT SINCE IT LOOKS
LIKE THE LOW WILL TAKE A SLIGHT OFFSHORE TRACK THE SNOW LEVELS WILL
NOT BE AS LOW AS THEY WERE FCST EARLIER WHEN THE MDLS HAD MORE OF A
OVERLAND TRACK. SNOW LEVELS WILL BE BETWEEN 4500 AND 5000 FEET THIS
MORNING...THEN WILL LOWER TO BETWEEN 3000 AND 4000 FEET TONIGHT. AS
MUCH AS A FOOT OF SNOW MAY FALL IN THE MOUNTAINS OF VENTURA AND LOS
ANGELES COUNTIES LATER TODAY AND TONIGHT.
OVERALL...RAINFALL TOTALS ARE NOT EXPECTED TO BE EXCEPTIONALLY
HEAVY...AND WILL BE HIGHLY VARIABLE DUE TO THE SHOWERY NATURE OF THE
PRECIPITATION. HOWEVER...EXPECT RAINFALL TOTALS TO AVERAGE ONE THIRD
OF AN INCH TO ONE INCH ACROSS THE AREA...ALTHOUGH LOCAL TOTALS OVER
2 INCHES ARE POSSIBLE IN AREAS THAT RECEIVE THUNDERSTORMS.
PEAK RAINFALL RATES OF ONE HALF TO THREE QUARTERS OF AN INCH PER
HOUR ARE POSSIBLE IN HEAVIER SHOWERS AND THUNDERSTORMS. THE MOST
LIKELY TIME PERIOD FOR THE HEAVY SHOWERS ACROSS SAN LUIS OBISPO AND
SANTA BARBARA COUNTIES WILL BE THIS MORNING THROUGH THIS
AFTERNOON...AND ACROSS VENTURA AND LOS ANGELES COUNTIES THIS
AFTERNOON THROUGH LATE THIS EVENING.
SNOW ACCUMULATIONS FOR THE L.A. AND VTA MTNS WILL GENERALLY BE
BETWEEN 6 AND 12 INCHES. LOCAL AMOUNTS UP TO 16 INCHES WILL BE
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. THE SLO
AND SBA MTNS WILL LIKELY SEE BETWEEN 3 AND 6 INCHES OF NEW SNOW. THE
LOW SNOW LEVELS WILL ALSO ALLOW FOR AN INCH OR TWO OF SNOW IN
FOOTHILLS OF THE ANTELOPE...CUYAMA...AND SLO INTERIOR VLYS.
THE STORM WILL EXIT THE AREA WEDNESDAY AND NOW LOOKS LIKE IT WILL
EXIT ALONG A MORE SOUTHWESTERLY PATH WHICH WILL ELIMINATE THE WRAP
AROUND FLOW INTO THE NORTH SLOPES OF MTNS. SKIES WILL CLEAR IN THE
WAKE OF THE STORM BUT WITH 556DM HGTS OVERHEAD WEDNESDAY MAX TEMPS
IN THE COASTS AND VLYS WILL STRUGGLE TO REACH THE LOWER 60S.
THURSDAY WILL BE UNEVENTFUL WITH A RIDGE IN PLACE. THE ONLY QUESTION
IS WEATHER TO CALL THE SLO/SBA SKIES MOSTLY SUNNY OR PARTLY CLOUDY
AS SOME MOISTURE WORKS ITS WAY THROUGH THE TOP OF THE RIDGE. HGTS
WILL BE UP A FEW DECAMETERS AND MAX TEMPS WILL WARM A FEW DEGREES
FROM WEDNESDAYS CHILLY READINGS.
.LONG TERM (FRI-MON)...
GFS AND EC IN DECENT AGREEMENT FOR THE EXTENDED PERIOD. BOTH NOW
SHOW NO HOPE OF RAIN FROM THE DYING FRONT ON FRIDAY. THE ONLY THAT
HAPPENS IS THE HGTS GET KNOCKED DOWN SOME AND MAX TEMPS WILL BE
SIMILAR TO THURSDAYS.
A RIDGES BULGES INTO THE AREA OVER THE WEEKEND WITH ENOUGH OFFSHORE
FLOW TO CREATE A NICE BUMP UP IN TEMPS AND MAX TEMPS IN THE LOWER
70S ACROSS THE L.A. CSTS. THE RIDGE DOES NOT MOVE MUCH AND AT THIS
TIME IT LOOKS LIKE NEXT MONDAY WILL SIMILAR TO SUNDAY.
&&
.AVIATION...09/1930Z.
SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH A VERY COLD UPPER
LEVEL LOW DROPPING SOUTH ALONG THE COAST WILL CONTINUE INTO THIS
EVENING. THERE WILL BE MVFR TO LOCAL IFR CONDITIONS IN BRIEF HEAVY
RAIN. VFR CONDITIONS WILL AGAIN BECOME MORE PREVALENT LATE THIS
EVENING AND TONIGHT.
KLAX...GOOD CONFIDENCE IN MVFR TO IFR CONDITIONS IN BRIEF HEAVY RAIN
AND SMALL HAIL. ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE. THE
ACTIVITY WILL DIE DOWN LATER THIS EVENING AND OVERNIGHT.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
&&
$$
PUBLIC...RORKE
AVIATION...SWEET
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSTO 091846
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 AM PST TUE FEB 9 2010
.DISCUSSION...
.UPDATE...COLD UPPER LEVEL LOW WILL SHIFT SOUTH ALONG THE CALIFORNIA
COAST FROM NEAR THE BAY AREA TO NEAR SANTA BARBARA THIS EVENING. A
BAND OF HEAVY RAIN DEVELOPED IN DEFORMATION AXIS FROM LODI TO JUST
EAST OF STOCKTON. KDAX FFMP INDICATED RAINFALL RATES IN EXCESS OF AN
INCH AN HOUR EARLIER. THE WRF SHOWS THIS BAND WILL SLIDE SOUTH LATER
THIS MORNING. MORE MODERATE TO HEAVY SHOWERS COULD SHIFT INTO
STANISLAUS AND CALAVERAS COUNTIES LATER THIS MORNING. LOCAL PONDING
OF WATER IS POSSIBLE IN LOW LYING AREAS. SEVERE THUNDERSTORMS ARE
NOT ANTICIPATED DUE TO COOL SURFACE TEMPERATURES IN CLOUD COVER.
HOWEVER WE WILL BE WATCHING THE AREA ALONG I-5 WEST OF STOCKTON
NORTH TOWARD RIO VISTA AS THE LOW SLIDES SOUTH AND LOW LEVEL
SOUTHERLY FLOW INTERACTS WITH WRAP AROUND EASTERLY WINDS ON THE BACK
SIDE OF THE LOW. FUNNEL CLOUDS COULD CERTAINLY DEVELOP IN THIS AREA
IF ANY CLEARING CAN DEVELOP. ANOTHER FOCUS FOR SOME HEAVIER SHOWERS
LATER THIS MORNING COULD BE OVER COLUSA AND GLENN COUNTIES IN STRONG
LOW LEVEL EASTERLY FLOW. IN THE MOUNTAINS...STRONG UPPER DIVERGENCE
IN THE NE QUADRANT OF THE LOW MAY INCREASE SNOW SHOWERS SOUTH OF
I-80 LATER THIS MORNING INTO THE AFTERNOON. THE TREK OF THE LOW
ALONG THE COAST SHOULD LIMIT SNOWFALL BUT WILL KEEP A WARY EYE OUT
TO SEE IF WE NEED ANY SORT OF WINTER WEATHER ADVISORY. HIGH PRESSURE
BUILDS INTO THE REGION TONIGHT AND TOMORROW. SG
&&
.AVIATION...
UPR LOW CNTRD ABT 70 NM WSW OF KSFO MOVG SSE ALG CST TO NR KSAN BY
12Z WED. FOR CNTRL VLY...AREAS MVFR/IFR IN NMRS SHWRS WITH ISOLD
TSRA POSS. CONDS IMPVG FM N TO S THIS AFTN INTO EVE WITH VFR AFT
01Z. FOR CSTL/NRN INTR MTNS...LCL MVFR/IFR IN SHWRS TIL 00Z THEN
PDMT VFR. SN LVLS 030-040 AMSL. FOR W SLPS SIERNEV... WDSPRD MVFR
WITH AREAS IFR/LIFR IN SHWRS TIL 02Z THEN IMPVG CONDS FM N TO S. SN
LVLS 040-055 AMSL. S-SELY FLOW ALF VRG TO NLY ARND 06Z WED.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPSR 091801 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1059 AM MST TUE FEB 9 2010
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
EXPECT AN INCREASE IN CLOUDINESS MAINLY OVER FAR SOUTHEASTERN
CALIFORNIA AND WEST-CENTRAL ARIZONA TODAY AS A LOW PRESSURE SYSTEM
APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW SHOWERS...AS
WELL AS A SLIGHT CHANCE OF A THUNDERSTORM...WILL OCCUR OVER FAR
SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT
INTO EARLY WEDNESDAY...THEN MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL
ARIZONA WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL
PREVAIL THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL
REMAIN RATHER COOL. WARMER WEATHER WILL SLOWLY RETURN HEADING INTO
THE WEEKEND...WITH ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED JUST SW OF SAN FRANCISCO AS OF 17Z (10AM
MST)...AND CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS.
MODELS IN GOOD AGREEMENT REGARDING TRACK OF THIS LOW...KEEPING IT ON
A PATH THAT PARALLELS THE CALIFORNIA COAST DURING THE NEXT 24 HRS...
PLACING IT JUST WEST OF SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT
TO JUST SOUTH AND WEST OF ORGAN PIPE NM BY 00Z THURSDAY. ADJUSTED
POP/QPF/SKY GRIDS TO BETTER REFLECT THE STORM TRACK...WHICH...AS
MIDSHIFT NOTES...WILL BE A LITTLE BIT TO THE SOUTH AND WEST OF WHAT
WAS PREVIOUSLY EXPECTED. AS SUCH...PRECIPITATION WILL BE MOST LIKELY
OVER FAR SE CALIFORNIA/SW AZ TONIGHT (WINTER WX ADVISORY FOR THE
JOSHUA TREE NATIONAL PARK LOOKS GOOD)...OVER SOUTHWEST AND EXTREME
SOUTH-CENTRAL AZ (SOUTH OF METRO PHOENIX) WEDNESDAY...AND OVER THE
HIGHER TERRAIN OF SOUTH-CENTRAL AZ (SOME SNOW ACCUMULATION EXPECTED
AT AND ABOVE 4000 FEET...REFER TO THE HAZARDOUS WEATHER OUTLOOK FOR
MORE DETAILS) AND SOUTHEAST ARIZONA WEDNESDAY NIGHT. AS THINGS NOW
STAND...PRECIP TOTALS FROM THIS STORM WILL BE ONLY ONE TO TWO TENTHS
OF AN INCH OVER SOUTH-CENTRAL AZ...ONE QUARTER TO ONE THIRD INCH
OVER FAR SOUTHEAST CALIFORNIA SOUTHWEST ARIZONA...AND ABOUT ONE
THIRD INCH OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL AZ.
.PREVIOUS DISCUSSION...
IT NOW APPEARS THE STRONGEST FORCING WILL IMPACT OUR WRN CWA...THEN
SWING SOUTH AND EAST OF OUR AREA. OVERALL SYSTEM REMAINS VERY
IMPRESSIVE WITH IT/S FORCING FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE IN SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S ON THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
KPHX AND KIWA...
UPPER LOW TRACKING ALONG CALIF COAST WILL BRING HIGH LEVEL MSTR INTO
SOUTH CENTRAL ARIZONA LATER TODAY. LIGHT SE WINDS STILL EXPECTED AT
SKY HARBOR THRU 09/22Z...AS MSTR ABOVE 8 THSD FT STREAMS INTO THE
AREA. PRECIP LIKELY TO HOLD OFF UNTIL WEDNESDAY AS BULK OF
ENERGY/LIFT STAYS TO OUR WEST. BY 10/15Z THE LOWER CIGS...8-10 THSD
FT WILL FILTER INTO THE METRO AREA ALONG WITH LGT RAIN.
KIPL AND KBLH...
NORTH-SOUTH LINE OF LGT SHOWERS WITH CIGS 6-8 THSD FT WILL BRUSH
ACROSS CALIF DESERTS THRU 10/00Z. ADDITIONAL SHOWERS LIKELY TO BRING
BEST CHANCE OF SHOWERS AFT DARK AT BOTH KIPL/KBLH. GOOD CONFIDENCE
THAT LOWER VSBYS WILL ACCOMPANY THE PRECIP AND CIGS...AND 5-7 MILES
VSBYS STILL LOOK GOOD. GUSTY WINDS ALSO MAY REACH 20-25 KTS SPCLY
ASSOCD WITH ISOLD TSTMS. TIMING OF CLEARING TREND STILL GOOD BY WED
AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
000
FXUS66 KMTR 091755 AAA
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
955 AM PST TUE FEB 9 2010
.DISCUSSION...AS OF 8:45 AM PST TUESDAY...SHOWERY TODAY. BREAK ON
WEDNESDAY FOLLOWED BY MORE RAIN FOR THURSDAY INTO FRIDAY.
UPPER LEVEL LOW ASSOCIATED WITH A SHARP TROUGH CONTINUES TO MOVE
SOUTHWARD ALONG THE COAST THIS MORNING. BASED OFF OF WV SATELLITE
LOOP THE CENTER IS CURRENTLY JUST OFF THE COAST BETWEEN SF AND
MONTEREY BAY AND DIVING TO THE SOUTH AROUND 15 KT. RAINFALL CAME IN
EARLIER THAN EXPECTED LAST NIGHT AS A WEAK FEATURE IN ADVANCE OF THE
TROUGH. 24 HOUR TOTALS THROUGH 8AM HAVE GENERALLY BEEN 1/4"-1/2".
KMUX RADAR RETURNS HAVE SWITCHED FROM WIDESPREAD TO MORE SHOWERY
THIS MORNING WHICH WILL BE THE PATTERN FOR THE DAY AS MODERATE
INSTABILITY COMBINED WITH COOL TEMPERATURES AND SOME BREAKS IN THE
CLOUDS WILL ALLOW FOR MULTIPLE BANDS TO ROTATE THROUGH THE DAY.
WOULD DEFINITELY EXPECT MANY LOCATIONS TO REPORT PARTLY/MOSTLY SUNNY
SKIES ONE HOUR WITH RAIN THE NEXT. BASED OFF OF SURFACE OBS...
FREEZING LEVEL HAS SETTLED SOMEWHERE BETWEEN 3000 AND 3500 FEET AND
WOULD CERTAINLY EXPECT TO GET REPORTS OF A FEW INCHES OF SNOW OVER
THE HIGHER ELEVATIONS. MOUNT HAMILTON SPOTTER DID REPORT ONLY 1" AS
OF 8 AM. WILL ALLOW THE WINTER WEATHER ADVISORY TO CONTINUE OVER
MONTEREY COUNTY. TEMPERATURES OVER THE SANTA CRUZ MOUNTAINS APPEAR
TOO WARM TO WARRANT AN ADVISORY THERE. BOTH THE DIABLO RANGE AND THE
MOUNTAINS OF SAN BENITO WILL BE COLD ENOUGH FOR SNOW...HOWEVER
PRECIPITATION WILL BE MORE LIMITED IN THOSE SPOTS DUE TO THE TRACK OF
THE LOW SO WILL NOT ISSUE A PRODUCT THERE. OBVIOUSLY IF THE LOW DOES
DIVERT MORE TO THE EAST THAN EXPECTED...THAT THINKING COULD CHANGE.
SKIES WILL BEGIN TO CLEAR OVERNIGHT ESPECIALLY TO THE NORTH WHICH
WILL ALLOW TEMPERATURES TO DROP. WIDESPREAD 30S ARE EXPECTED OVER THE
NORTH BAY WITH PATCHY FOG AND FROST A DEFINITE POSSIBILITY.
AFTER A BREAK TOMORROW...RAIN RETURNS LATE ON THURSDAY AS A SURFACE
FRONT AND UPPER LEVEL TROUGH MOVE TO THE PACNW COAST. THIS WILL BE
FOLLOWED BY A SECONDARY TROUGH ON FRIDAY. RAIN WILL MOVE INTO THE
NORTH BAY BY THURSDAY EVENING AND ACROSS THE ENTIRE CWA THURSDAY
NIGHT. VARIOUS MODEL RUNS CONTINUE TO FOCUS THE BRUNT OF ENERGY TO
OUR NORTH WITH JUST THE FAR SOUTHERN EDGE OF PRECIP IMPACTING OUR
AREA. 2 DAY RAIN TOTALS REMAIN UNIMPRESSIVE AT THIS TIME WITH UP TO
3/4" FOR THE FAR NORTH DOWN TO LESS THAN A 1/10" FOR SOUTHERN
MONTEREY AND SAN BENITO. CNRFC 3 DAY FORECAST FOR TOMORROW WILL
GIVE A MUCH MORE DETAILED DEPICTION OF THE EXPECTED PRECIP.
BEYOND THAT BOTH THE ECMWF AND GFS BUILD A STRONG RIDGE/OMEGA BLOCK
BACK TO THE WESTERN CONUS. NEXT WEEK IS SHAPING UP TO BE GENERALLY
DRY WITH TEMPERATURES NEAR OR A BIT ABOVE NORMAL.
&&
.AVIATION...AS OF 10:00 AM TUESDAY...UNSETTLED WEATHER TODAY AS THE
COLD CORE UPPER LOW REMAINS OVERHEAD. SHOWER ACTIVITY WILL BE HIT
OR MISS...BUT IT DOES APPEAR THAT THE BEST INSTABILITY WILL BE JUST
OFFSHORE. THAT BEING SAID...HAVE DECREASED SHOWERS FOR LOCATIONS N
OF KSJC. SKIES WILL CLEAR ON THE BACKSIDE OF THE LOW LATER TODAY.
VALLEY FOG WILL LIKELY DEVELOP TONIGHT AT KSTS.
VICINITY OF KSFO...UPDATED FOR MORE SOUTHEAST FLOW AS THE UPPER LOW
HANGS TO THE WEST. HAVE ALSO WENT MORE VCSH AS MUCH OF THE SHOWER
ACTIVITY IS TO THE SOUTH AND WEST OF THE AIRPORT. THAT IS NOT TO
SAY A ROGUE SHOWER WILL NOT PASS OVERHEAD.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...SHOWERS WILL PREVAIL THROUGH THE
AFTERNOON...DEVELOPING OFFSHORE AND GRADUALLY DRIFTING ONSHORE.
CIGS MAY BRIEFLY LOWER WITH THESE SHOWERS. CLEAR LATER TODAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...WINTER WEATHER ADVISORY ABOVE 3000 FEET FOR
SANTA LUCIA MTNS AND LOS PADRES NATIONAL FOREST
STARTING 6AM THIS MORNING.
.SCA...FOR ALL COASTAL WATERS AND MONTEREY BAY
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: MM
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSGX 091753 CCA
AFDSGX
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN DIEGO CA
945 AM PST TUE FEB 9 2010
.SYNOPSIS...CORRECTED
A COLD LOW PRESSURE SYSTEM MOVING DOWN THE CALIFORNIA COAST WILL
TRACK SOUTHEAST ACROSS THE COASTAL WATERS TONIGHT. THE LOW IS
FORECAST TO TRACK EAST ACROSS NORTHERN BAJA CALIFORNIA EARLY
WEDNESDAY AND THEN MOVE EAST OF THE REGION BY WEDNESDAY EVENING.
THIS WILL BRING PERIODS OF PRECIPITATION THROUGH WEDNESDAY TO
SOUTHWEST CALIFORNIA WITH A CHANCE OF THUNDERSTORMS. SNOW LEVELS
WILL LOWER TO NEAR 3000 FEET LATE TONIGHT THROUGH EARLY WEDNESDAY.
DRY AND GRADUALLY WARMER THURSDAY THROUGH FRIDAY. STRONGER HIGH
PRESSURE THIS WEEKEND MAY BRING WARMING TO ABOVE SEASONAL AVERAGES
THROUGH TUESDAY AND WEAK OFFSHORE WINDS ARE POSSIBLE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.SHORT TERM...TODAY THROUGH THURSDAY...CORRECTED MINOR TYPOS...
DIVERGENCE ALOFT AND RESULTING UPWARD VERTICAL MOTION AHEAD OF
APPROACHING COLD FRONT/UPPER LOW IS RESPONSIBLE FOR PRECIPITATION
STARTING EARLY THIS MORNING. RUC13 MODEL SHOWED OMEGA VALUES OF
-6 UBAR/SEC IN THE 850-500 MB LAYER OVER ORANGE COUNTY/SW SAN
BERNARDINO COUNTY THROUGH 0900 PST WITH SIMILAR VALUES DEVELOPING
OVER WESTERN RIVERSIDE/EASTERN SAN DIEGO COUNTY AFTER 1000 PST
AND INCREASING THEREAFTER. THE COLD FRONT...MARKED BY LINE OF 40 TO
50 DBZ ECHOES MOVING SOUTHEAST 22 KNOTS/25 MPH...EXTRAPOLATES TO THE
ORANGE COUNTY/LA COUNTY/SAN BERNARDINO COUNTY LINE AROUND 1 PM.
MODELS WERE IN GOOD AGREEMENT ON POSITION AND TIMING OF UPPER LOW...
UNTIL THE 09/12Z NAM RUN CAME IN. THIS MODEL IS NOW ABOUT 6 HOURS
SLOWER ON MOVING THE UPPER LOW SOUTHEAST FROM CURRENT POSITION OFF
CENTRAL CALIFORNIA COAST...ACROSS OR JUST OFFSHORE SAN DIEGO...AND
THEN EAST ACROSS NORTHERN GULF OF CALIFORNIA...OTHERWISE TRACK IS
CONSISTENT WITH OTHER MODEL RUNS. CONSENSUS IS THAT THIS SLOWER
MOVEMENT IS IN ERROR. SINCE CURRENT FORECAST TIMING IS ALIGNED WITH
FASTER GFS/ECMWF MODELS NO SIGNIFICANT CHANGES ANTICIPATED TO
FORECAST. COLD CORE...WITH 500 MB TEMPERATURES OF -30C AND 850 MB
TEMPERATURES -4C PASSES OVER SOUTHERN CALIFORNIA BIGHT AND SW
CALIFORNIA THIS EVENING/TONIGHT. GIVEN THESE VALUES AND 925 MB
TEMPERATURES ONLY COOLING TO 4 TO 6 DEGREES CELSIUS...LOWER LAPSE
RATES BECOME QUITE UNSTABLE THIS EVENING THROUGH EARLY WEDNESDAY
MORNING. MAY HAVE SEVERE WEATHER WATCHES OUT BEFORE THIS EVENT IS
OVER.
FOR WEDNESDAY AFTERNOON SLOW WINDING DOWN OF SHOWER ACTIVITY
WEST OF MOUNTAINS AS CENTER OF LOW EXPECTED TO BE OVER NORTHERN GULF
OF CALIFORNIA BUT UPSLOPE FLOW AND WRAP AROUND MOISTURE WILL KEEP
RAIN AND SNOW GOING OVER DESERT AREAS/EAST AND NORTH SLOPES OF
MOUNTAINS. WEDNESDAY NIGHT THROUGH THURSDAY DRYING OUT UNDER THE
BUILDING HIGH PRESSURE RIDGE. MAY REINTRODUCE FROST FOR INLAND
VALLEYS WEDNESDAY NIGHT/THURSDAY MORNING AS WINDS FORECAST TO GO TO
NEAR CALM AND SKIES TO BE CLEAR. LOWER DESERT AREAS WILL LIKELY
STILL HAVE ENOUGH WIND TO KEEP FROST FROM FORMING THERE.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY...
GENERALLY FAIR AND DRY WITH A WARMING TREND THROUGH THIS PERIOD.
FLAT RIDGE FOR FRIDAY WITH TROUGH PASSING INLAND TO THE NORTH WILL
ALLOW MID/HIGH CLOUDS TO MOVE ACROSS THE FORECAST AREA. RIDGE
REBUILDS SATURDAY AND SUNDAY CREATING A FAVORABLE PATTERN FOR
LIGHT TO MODERATE OFFSHORE WINDS. RIDGE FLATTENS SOMEWHAT MONDAY AND
TUESDAY AS TROUGHS PASS INLAND WELL TO THE NORTH.
&&
.AVIATION...
091445Z...COLD FRONT MOVING THROUGH POINT CONCEPTION AREA THIS
MORNING SHOULD PASS THROUGH KSNA AROUND 18Z...KONT AROUND 19Z...AND
KSAN/KPSP AROUND 21Z. TRAILING EDGE OF THE FRONT SHOULD PASS THROUGH
ABOUT 2 HOURS LATER. MULTIPLE LAYERS OF BROKEN TO OVERCAST STRATOCU
OVER THE AREA AHEAD OF THE FRONT SHOULD BECOME MOSTLY OVERCAST
LAYERS BETWEEN 1500 AND 3000 FEET MSL. VISIBILITIES MAINLY 3 TO 5
MILES IN PRECIPITATION EXCEPT LOCALLY DOWN TO 1 MILE IN HEAVIER
PRECIPITATION. MOUNTAINS WILL BECOME MOSTLY OBSCURED BY NOONTIME.
BEHIND THE FRONT AND CONTINUING THROUGH THE NIGHT INTO WEDNESDAY
MORNING...MOSTLY BROKEN CU/TCU WITH BASES BETWEEN 2000 AND 3000 FEET
AND TOPS TO 10000 FEET MSL EXCEPT TOPS TO FL250 IN ISOLATED TSTMS.
HORTON
&&
.MARINE...
WATERSPOUT REPORTED IN PAST HOUR OFF SAN DIEGO COAST. POTENTIAL
EXISTS FOR ADDITIONAL WATERSPOUTS TO DEVELOP THROUGH WEDNESDAY
MORNING. SEE SPECIAL MARINE WARNINGS AND MARINE WEATHER STATEMENT.
&&
.HYDROLOGY...
LOWERED FLASH FLOOD THREAT FOR SAN BERNARDINO MOUNTAINS AFTER 10 PM
DUE TO LOWERING FREEZING LEVEL AND MOST PRECIPITATION BECOMING
FROZEN. RAINFALL RATES OF 0.50 TO 1.00 INCHES FROM 1 PM THROUGH 10 PM
POSSIBLE AS THIS IS PERIOD OF STRONGEST VERTICAL MOTION DUE TO
STRONG DIVERGENCE ALOFT FROM LEFT FRONT QUADRANT OF JET STREAM AND
FRONTAL LIFTING. MAY BE ABLE TO DROP FLASH FLOOD WATCH FOR ALL AREAS
AFTER THIS. UNLESS SLOWER NAM MODEL VERIFIES...CURRENT STORM
RAINFALL TOTALS IN QPFSAN FORECAST LOOK REASONABLE. MAIN DIFFERENCE
WOULD BE NORTH AND EAST SLOPES OF MOUNTAINS/LOWER DESERTS WOULD BE
SUBJECT TO WRAP AROUND MOISTURE FOR ANOTHER 6 HOURS...INTO WEDNESDAY
EVENING.
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH 6 AM PST WEDNESDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE
INLAND EMPIRE-SANTA ANA MOUNTAINS AND FOOTHILLS.
FLASH FLOOD WATCH THROUGH 10 PM TONIGHT BELOW 5000 FEET FOR
SAN BERNARDINO COUNTY MOUNTAINS EXCEPT CONTINUING THROUGH 1 AM
BELOW 4000 FEET.
WINTER WEATHER ADVISORY UNTIL 6 AM PST WEDNESDAY BELOW 6000
FEET FOR SAN BERNARDINO COUNTY MOUNTAINS.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY ABOVE 6000 FEET FOR RIVERSIDE COUNTY MOUNTAINS-
SAN BERNARDINO COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY BELOW 6000 FEET FOR RIVERSIDE COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY ABOVE 3500 FEET FOR APPLE AND LUCERNE VALLEYS-.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM PST
WEDNESDAY ABOVE 3500 FEET FOR SANTA ANA MOUNTAINS.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 6 AM PST
WEDNESDAY FOR SAN DIEGO COUNTY MOUNTAINS.
SPECIAL WEATHER STATEMENT TO SUMMARIZE ABOVE AND COVER OTHER
EFFECTS IN REMAINING ZONES
PZ...MARINE WEATHER STATEMENT BOTH INNER AND OUTER COASTAL
WATERS FOR THREAT OF THUNDERSTORMS AND WATERSPOUTS THROUGH
WEDNESDAY MORNING.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
SEVERE WEATHER...PG/MM
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KLOX 091728
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
930 AM PST TUE FEB 9 2010
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TODAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOL TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK.
&&
.SHORT TERM (TODAY-THU)...
COLD UPPER LOW DROPPING SOUTH ALONG THE COAST TODAY, CURRENTLY
LOCATED JUST WEST OF SFO. THE FIRST BAND OF SHOWERS IS MOVING
THROUGH THE AREA THIS MORNING AND WILL SWEEP MOVE INTO LA COUNTY BY
NOON. THERE ARE SOME LOCALLY HEAVY SHOWERS ASSOCIATED WITH IT BUT SO
FAR NO CLOUD TO GROUND LIGHTNING HAS BEEN DETECTED. A SECONDARY BAND
OF SHOWERS IS MOVING ONSHORE ALONG THE CENTRAL COAST THOUGH SO FAR
THE PRECIP FROM IT HAS BEEN LIGHTER. ALTHOUGH THERE SOME BRIEF HEAVY
RAIN IS POSSIBLE WITH TODAY, THE POTENTIAL FOR MORE ACTIVE WEATHER
TONIGHT AS THE UPPER LOW MOVES OVERHEAD POSES A GREATER THREAT,
ESPECIALLY FOR OUR BURN AREAS. THE MAIN CAVEAT TO THIS THOUGH IS THE
MODELS ARE SHOWING THE HIGHEST MOISTURE AND INSTABILITY REMAINING
OFFSHORE. SO THERE IS A CHANCE THAT THE HEAVIER PRECIPITATION
TONIGHT WILL SWING WEST AND SOUTH OF THE AREA. BUT AS HAS BEEN
EMPHASIZED IN MANY PREVIOUS DISCUSSIONS, EVEN A MINOR SHIFT IN THE
TRACK OF THE LOW COULD RESULT IN WIDELY DIFFERENT WEATHER
CONDITIONS. BEST TO STAY THE COURSE NOW AND SEE HOW THINGS EVOLVE
TODAY.
***FROM PREVIOUS DISCUSSION***
OVERALL...RAINFALL TOTALS ARE NOT EXPECTED TO BE EXCEPTIONALLY
HEAVY...AND WILL BE HIGHLY VARIABLE DUE TO THE SHOWERY NATURE OF THE
PRECIPITATION. HOWEVER...EXPECT RAINFALL TOTALS TO AVERAGE ONE THIRD
OF AN INCH TO ONE INCH ACROSS THE AREA...ALTHOUGH LOCAL TOTALS OVER
2 INCHES ARE POSSIBLE IN AREAS THAT RECEIVE THUNDERSTORMS.
PEAK RAINFALL RATES OF ONE HALF TO THREE QUARTERS OF AN INCH PER
HOUR ARE POSSIBLE IN HEAVIER SHOWERS AND THUNDERSTORMS. THE MOST
LIKELY TIME PERIOD FOR THE HEAVY SHOWERS ACROSS SAN LUIS OBISPO AND
SANTA BARBARA COUNTIES WILL BE THIS MORNING THROUGH THIS
AFTERNOON...AND ACROSS VENTURA AND LOS ANGELES COUNTIES THIS
AFTERNOON THROUGH LATE THIS EVENING.
SNOW ACCUMULATIONS FOR THE L.A. AND VTA MTNS WILL GENERALLY BE
BETWEEN 6 AND 12 INCHES. LOCAL AMOUNTS UP TO 16 INCHES WILL BE
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. THE SLO
AND SBA MTNS WILL LIKELY SEE BETWEEN 3 AND 6 INCHES OF NEW SNOW. THE
LOW SNOW LEVELS WILL ALSO ALLOW FOR AN INCH OR TWO OF SNOW IN
FOOTHILLS OF THE ANTELOPE...CUYAMA...AND SLO INTERIOR VLYS.
THE STORM WILL EXIT THE AREA WEDNESDAY AND NOW LOOKS LIKE IT WILL
EXIT ALONG A MORE SOUTHWESTERLY PATH WHICH WILL ELIMINATE THE WRAP
AROUND FLOW INTO THE NORTH SLOPES OF MTNS. SKIES WILL CLEAR IN THE
WAKE OF THE STORM BUT WITH 556DM HGTS OVERHEAD WEDNESDAY MAX TEMPS
IN THE COASTS AND VLYS WILL STRUGGLE TO REACH THE LOWER 60S.
THURSDAY WILL BE UNEVENTFUL WITH A RIDGE IN PLACE. THE ONLY QUESTION
IS WEATHER TO CALL THE SLO/SBA SKIES MOSTLY SUNNY OR PARTLY CLOUDY
AS SOME MOISTURE WORKS ITS WAY THROUGH THE TOP OF THE RIDGE. HGTS
WILL BE UP A FEW DECAMETERS AND MAX TEMPS WILL WARM A FEW DEGREES
FROM WEDNESDAYS CHILLY READINGS.
.LONG TERM (FRI-MON)...
GFS AND EC IN DECENT AGREEMENT FOR THE EXTENDED PERIOD. BOTH NOW
SHOW NO HOPE OF RAIN FROM THE DYING FRONT ON FRIDAY. THE ONLY THAT
HAPPENS IS THE HGTS GET KNOCKED DOWN SOME AND MAX TEMPS WILL BE
SIMILAR TO THURSDAYS.
A RIDGES BULGES INTO THE AREA OVER THE WEEKEND WITH ENOUGH OFFSHORE
FLOW TO CREATE A NICE BUMP UP IN TEMPS AND MAX TEMPS IN THE LOWER
70S ACROSS THE L.A. CSTS. THE RIDGE DOES NOT MOVE MUCH AND AT THIS
TIME IT LOOKS LIKE NEXT MONDAY WILL SIMILAR TO SUNDAY.
&&
.AVIATION...
09/1125Z
COLD UPPER LOW WILL DROP SOUTH ACROSS THE AREA TODAY...BRINGING AN
UNSTABLE AIR MASS ALONG WITH MVFR (AND POTENTIALLY ISOLATED IFR)
CONDS TO THE AREA. GIVEN THE INSTABILITY ASSOCIATED WITH THE STORM
WILL INTRODUCE VCTS REMARKS FOR ALL TAF SITES WITH THE 12Z PACKAGE.
BEST CHANCES FOR SHRA/TS WILL BE THIS MORNING/EARLY AFTERNOON NORTH
OF POINT CONCEPTION...AND THIS AFTERNOON/EVENING SOUTH OF POINT
CONCEPTION. ANY TSTMS THAT FORM WILL BE CAPABLE OF GUSTY WINDS...
BRIEF HEAVY SHOWERS AND HAIL.
KLAX...LOW TO MODERATE CONFIDENCE IN 12Z TAF. TIMING OF SHOWERS AND
POSSIBLE THUNDERSTORMS COULD BE AN HOUR OR TWO EARLY THAN FORECAST
IN TAF. AN EAST WINDS 5-8 KNOTS WILL CONTINUE THROUGH THE MORNING
HOURS.
KBUR...LOW TO MODERATE CONFIDENCE IN 12Z TAF. TIMING OF SHOWERS
AND POSSIBLE THUNDERSTORMS COULD BE AN HOUR OR TWO EARLY THAN
FORECAST IN TAF.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...WOFFORD/RORKE
AVIATION...THOMPSON
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 091727
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 AM MST TUE FEB 9 2010
.SYNOPSIS...
EXPECT AN INCREASE IN CLOUDINESS MAINLY OVER FAR SOUTHEASTERN
CALIFORNIA AND WEST-CENTRAL ARIZONA TODAY AS A LOW PRESSURE SYSTEM
APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW SHOWERS...AS
WELL AS A SLIGHT CHANCE OF A THUNDERSTORM...WILL OCCUR OVER FAR
SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY TONIGHT
INTO EARLY WEDNESDAY...THEN MAINLY OVER SOUTHWEST AND SOUTH-CENTRAL
ARIZONA WEDNESDAY AND WEDNESDAY EVENING. DRIER CONDITIONS WILL
PREVAIL THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL
REMAIN RATHER COOL. WARMER WEATHER WILL SLOWLY RETURN HEADING INTO
THE WEEKEND...WITH ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
UPPER LOW THAT WILL AFFECT OUR WEATHER DURING THE NEXT COUPLE OF
DAYS WAS CENTERED JUST SW OF SAN FRANCISCO AS OF 17Z (10AM
MST)...AND CONTINUED TO MOVE TOWARD THE SSE AT ABOUT 20 KNOTS.
MODELS IN GOOD AGREEMENT REGARDING TRACK OF THIS LOW...KEEPING IT ON
A PATH THAT PARALLELS THE CALIFORNIA COAST DURING THE NEXT 24 HRS...
PLACING IT JUST WEST OF SAN DIEGO BY 12Z WEDNESDAY...THEN MOVING IT
TO JUST SOUTH AND WEST OF ORGAN PIPE NM BY 00Z THURSDAY. ADJUSTED
POP/QPF/SKY GRIDS TO BETTER REFLECT THE STORM TRACK...WHICH...AS
MIDSHIFT NOTES...WILL BE A LITTLE BIT TO THE SOUTH AND WEST OF WHAT
WAS PREVIOUSLY EXPECTED. AS SUCH...PRECIPITATION WILL BE MOST LIKELY
OVER FAR SE CALIFORNIA/SW AZ TONIGHT (WINTER WX ADVISORY FOR THE
JOSHUA TREE NATIONAL PARK LOOKS GOOD)...OVER SOUTHWEST AND EXTREME
SOUTH-CENTRAL AZ (SOUTH OF METRO PHOENIX) WEDNESDAY...AND OVER THE
HIGHER TERRAIN OF SOUTH-CENTRAL AZ (SOME SNOW ACCUMULATION EXPECTED
AT AND ABOVE 4000 FEET...REFER TO THE HAZARDOUS WEATHER OUTLOOK FOR
MORE DETAILS) AND SOUTHEAST ARIZONA WEDNESDAY NIGHT. AS THINGS NOW
STAND...PRECIP TOTALS FROM THIS STORM WILL BE ONLY ONE TO TWO TENTHS
OF AN INCH OVER SOUTH-CENTRAL AZ...ONE QUARTER TO ONE THIRD INCH
OVER FAR SOUTHEAST CALIFORNIA SOUTHWEST ARIZONA...AND ABOUT ONE
THIRD INCH OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL AZ.
.PREVIOUS DISCUSSION...
IT NOW APPEARS THE STRONGEST FORCING WILL IMPACT OUR WRN CWA...THEN
SWING SOUTH AND EAST OF OUR AREA. OVERALL SYSTEM REMAINS VERY
IMPRESSIVE WITH IT/S FORCING FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE IN SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S ON THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
KPHX AND KIWA...
LIGHT WINDS FROM THE EAST THIS MORNING ARE EXPECTED TO BECOME
VARIABLE AFTER 2000 TO 2200 GMT THIS AFTERNOON...THEN FROM THE EAST
AGAIN AFTER ABOUT 0400 GMT AT KIWA AND 0800 GMT AT KPHX TONIGHT.
HIGH CLOUDINESS IS EXPECTED TO INCREASE FROM THE SOUTHWEST BY THIS
AFTERNOON AND TONIGHT WITH A FEW TO SCATTERED CLOUDS NEAR 7 AND 14
THOUSAND FEET.
KIPL AND KBLH...
LIGHT AND VARIABLE WINDS ARE EXPECTED THIS MORNING BECOMING FROM THE
SOUTH AROUND 10 KNOTS LATE THIS MORNING AND/OR THIS AFTERNOON...THEN
FROM THE SOUTHWEST AND WEST TONIGHT. INCREASING AND LOWERING
CLOUDINESS IS EXPECTED THROUGH THE PERIOD WITH CEILINGS LOWERING TO
6 THOUSAND FEET AFTER 0800 GMT TONIGHT AND AS LOW AS 4 THOUSAND FEET
AFTER 1000 GMT WITH VISIBILITY DROPPING TO NEAR 5 MILES IN SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KMTR 091722
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
915 AM PST TUE FEB 9 2010
.DISCUSSION...AS OF 9:15 AM PST TUESDAY...SHOWERY TODAY. BREAK ON
WEDNESDAY FOLLOWED BY MORE RAIN FOR THURSDAY INTO FRIDAY.
UPPER LEVEL LOW ASSOCIATED WITH A SHARP TROUGH CONTINUES TO MOVE
SOUTHWARD ALONG THE COAST THIS MORNING. BASED OFF OF WV SATELLITE
LOOP THE CENTER IS CURRENTLY JUST OFF THE COAST BETWEEN SF AND
MONTEREY BAY AND DIVING TO THE SOUTH AROUND 15 KT. RAINFALL CAME IN
EARLIER THAN EXPECTED LAST NIGHT AS A WEAK FEATURE IN ADVANCE OF THE
TROUGH MOVE ACROSS THE CWA. 24 HOUR TOTALS THROUGH 8AM HAVE GENERALLY
BEEN 1/4"-1/2".
KMUX RADAR RETURNS HAVE SWITCHED FROM WIDESPREAD TO MORE SHOWERY THIS
MORNING WHICH WILL BE THE PATTERN FOR THE DAY AS MODERATE INSTABILITY
COMBINED WITH COOL TEMPERATURES AND SOME BREAKS IN THE CLOUDS WILL
ALLOW FOR MULTIPLE BANDS TO ROTATE THROUGH THE DAY. WOULD DEFINITELY
EXPECT MANY LOCATIONS TO REPORT PARTLY/MOSTLY SUNNY SKIES ONE HOUR
WITH RAIN THE NEXT. BASED OFF OF SURFACE OBS...FREEZING LEVEL HAS
SETTLED SOMEWHERE BETWEEN 3000 AND 3500 FEET AND WOULD CERTAINLY
EXPECT TO GET REPORTS OF A FEW INCHES OF SNOW OVER THE HIGHER
ELEVATIONS. MOUNT HAMILTON SPOTTER DID REPORT ONLY 1" AS OF 8 AM.
WILL ALLOW THE WINTER WEATHER ADVISORY TO CONTINUE OVER MONTEREY
COUNTY WHERE CONDITIONS LOOK THE MOST FAVORABLE. TEMPERATURES OVER
THE SANTA CRUZ MOUNTAINS APPEAR TOO WARM TO WARRANT AN ADVISORY
THERE. BOTH THE DIABLO RANGE AND THE MOUNTAINS OF SAN BENITO WILL BE
COLD ENOUGH FOR SNOW...HOWEVER PRECIPITATION WILL BE MORE LIMITED IN
THOSE SPOTS DUE TO THE TRACK OF THE LOW SO WILL NOT ISSUE A PRODUCT
THERE. OBVIOUSLY IF THE LOW DOES DIVERT MORE TO THE EAST THAN
EXPECTED OR SLOWS DOWN...THAT THINKING COULD CHANGE. SKIES WILL BEGIN
TO CLEAR OVERNIGHT ESPECIALLY TO THE NORTH WHICH WILL ALLOW
TEMPERATURES TO DROP. WIDESPREAD 30S ARE EXPECTED OVER THE NORTH BAY
WITH PATCHY FOG AND FROST A DEFINITE POSSIBILITY.
AFTER A BREAK TOMORROW...RAIN RETURNS LATE ON THURSDAY AS A SURFACE
FRONT AND UPPER LEVEL TROUGH MOVE TO THE PACNW COAST. THIS WILL BE
FOLLOWED BY A SECONDARY TROUGH ON FRIDAY. RAIN WILL MOVE INTO THE
NORTH BAY BY THURSDAY EVENING AND ACROSS THE ENTIRE CWA THURSDAY
NIGHT. VARIOUS MODEL RUNS CONTINUE TO FOCUS THE BRUNT OF ENERGY TO
OUR NORTH WITH JUST THE FAR SOUTHERN EDGE OF PRECIP IMPACTING OUR
AREA. 2 DAY RAIN TOTALS REMAIN UNIMPRESSIVE AT THIS TIME WITH UP TO
3/4" FOR THE FAR NORTH DOWN TO LESS THAN A 1/10" FOR SOUTHERN
MONTEREY AND SAN BENITO. CNRFC 3 DAY FORECAST FOR TOMORROW WILL
GIVE A MUCH MORE DETAILED DEPICTION OF THE EXPECTED PRECIP.
BEYOND THAT BOTH THE ECMWF AND GFS BUILD A STRONG RIDGE/OMEGA BLOCK
BACK TO THE WESTERN CONUS. NEXT WEEK IS SHAPING UP TO BE GENERALLY
DRY WITH TEMPERATURES NEAR OR A BIT ABOVE NORMAL.
&&
.AVIATION...AS OF 4:00 AM TUESDAY...UPPER LOW JUST WEST OF KSFO AT
POST TIME. SURFACE BOUNDARY HAS ALREADY MOVED THROUGH AND WINDS AT
KSFO AND KOAK HAVE ALREADY SHIFTED TO WESTERLY...WITH A NOTED WIND
SHIFT ALREADY NOTED AT THE BUOYS AND COASTAL SITES. EXPECT KSJC TO
SHIFT SHORTLY WITH KNUQ ALREADY WSW. SHOWERS ARE NUMEROUS AS OF 12Z
WITH PEAK IN AREAL COVERAGE EXPECTED BETWEEN NOW AND 18Z...THEN
RAPIDLY DECREASING THROUGH MIDDAY AND AFTERNOON HOURS.
VICINITY OF KSFO...WEST WINDS TODAY MAINLY UNDER 12 KT. LIGHT RAIN
THIS MORNING WITH CIGS IN THE 3-5K RANGE...DECREASING RAPIDLY AFTER
18Z AS THE UPPER LOW SHIFTS SOUTH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO...BUT MORE WIDESPREAD PRECIP
EXPECTED OVER THE SOUTH END OF THE BAY DUE TO CLOSER PROXIMITY TO THE
UPPER LOW THIS MORNING.
MRY BAY AREA TERMINALS...WINDS HAVE SHIFT WESTERLY AT KMRY AND KSNS.
SHOWERS WILL CONTINUE TO MOVE ONSHORE THIS MORNING AND LINGER A
LITTLE LONGER AT THESE TERMINALS THROUGH MIDDAY AS UPPER LOW SHIFT
SOUTHWARD DOWN THE COAST. LOOKS PRETTY CLEAR THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...WINTER WEATHER ADVISORY ABOVE 3000 FEET FOR
SANTA LUCIA MTNS AND LOS PADRES NATIONAL FOREST
STARTING 6AM THIS MORNING.
.SCA...FOR ALL COASTAL WATERS AND MONTEREY BAY
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: RWW
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSTO 091721
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 AM PST TUE FEB 9 2010
.DISCUSSION...
.UPDATE...COLD UPPER LEVEL LOW WILL SHIFT SOUTH ALONG THE CALIFORNIA
COAST FROM NEAR THE BAY AREA TO NEAR SANTA BARBARA THIS EVENING. A
BAND OF HEAVY RAIN DEVELOPED IN DEFORMATION AXIS FROM LODI TO JUST
EAST OF STOCKTON. KDAX FFMP INDICATED RAINFALL RATES IN EXCESS OF AN
INCH AN HOUR EARLIER. THE WRF SHOWS THIS BAND WILL SLIDE SOUTH LATER
THIS MORNING. MORE MODERATE TO HEAVY SHOWERS COULD SHIFT INTO
STANISLAUS AND CALAVERAS COUNTIES LATER THIS MORNING. LOCAL PONDING
OF WATER IS POSSIBLE IN LOW LYING AREAS. SEVERE THUNDERSTORMS ARE
NOT ANTICIPATED DUE TO COOL SURFACE TEMPERATURES IN CLOUD COVER.
ANOTHER FOCUS FOR SOME HEAVIER SHOWERS THIS MORNING COULD BE OVER
COLUSA AND GLENN COUNTIES IN STRONG LOW LEVEL EASTERLY FLOW. IN THE
MOUNTAINS...STRONG UPPER DIVERGENCE IN THE NE QUADRANT OF THE LOW
MAY INCREASE SNOW SHOWERS SOUTH OF I-80 LATER THIS MORNING INTO THE
AFTERNOON. THE TREK OF THE LOW ALONG THE COAST SHOULD LIMIT SNOWFALL
BUT WILL KEEP A WARY EYE OUT TO SEE IF WE NEED ANY SORT OF WINTER
WEATHER ADVISORY. HIGH PRESSURE BUILDS INTO THE REGION TONIGHT AND
TOMORROW. SG
&&
.AVIATION...
UPR LOW CNTRD ABT 70 NM WSW OF KSFO MOVG SSE ALG CST TO NR KSAN BY
12Z WED. FOR CNTRL VLY...AREAS MVFR/IFR IN NMRS SHWRS WITH ISOLD
TSRA POSS. CONDS IMPVG FM N TO S THIS AFTN INTO EVE WITH VFR AFT
01Z. FOR CSTL/NRN INTR MTNS...LCL MVFR/IFR IN SHWRS TIL 00Z THEN
PDMT VFR. SN LVLS 030-040 AMSL. FOR W SLPS SIERNEV... WDSPRD MVFR
WITH AREAS IFR/LIFR IN SHWRS TIL 02Z THEN IMPVG CONDS FM N TO S. SN
LVLS 040-055 AMSL. S-SELY FLOW ALF VRG TO NLY ARND 06Z WED.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSTO 091717
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 AM PST TUE FEB 9 2010
.DISCUSSION...
.UPDATE...COLD UPPER LEVEL LOW WILL SHIFT SOUTH ALONG THE CALIFORNIA
COAST FROM NEAR THE BAY AREA TO NEAR SANTA BARBARA THIS EVENING. A
BAND OF HEAVY RAIN DEVELOPED IN DEFORMATION AXIS FROM NEAR LODI TO
JUST EAST OF STOCKTON. KDAX FFMP INDICATED RAINFALL RATES IN EXCESS
OF AN INCH AN HOUR EARLIER. THE WRF SHOWS THIS BAND WILL SLIDE SOUTH
LATER THIS MORNING. MORE MODERATE TO HEAVY SHOWERS COULD SHIFT INTO
STANISLAUS AND CALAVERAS COUNTIES LATER THIS MORNING. LOCAL PONDING
OF WATER IS POSSIBLE IN LOW LYING AREAS. SEVERE THUNDERSTORMS ARE
NOT ANTICIPATED DUE TO COOL SURFACE TEMPERATURES IN CLOUD COVER.
ANOTHER FOCUS FOR SOME HEAVIER SHOWERS THIS MORNING COULD BE OVER
COLUSA AND GLENN COUNTIES IN STRONG LOW LEVEL EASTERLY FLOW. IN THE
MOUNTAINS...STRONG UPPER DIVERGENCE IN THE NE QUADRANT OF THE LOW
MAY INCREASE SNOW SHOWERS SOUTH OF I-80 LATER THIS MORNING INTO THE
AFTERNOON. THE TREK OF THE LOW ALONG THE COAST SHOULD LIMIT SNOWFALL
BUT WILL KEEP A WARY EYE OUT TO SEE IF WE NEED ANY SORT OF WINTER
WEATHER ADVISORY. HIGH PRESSURE BUILDS INTO THE REGION TONIGHT AND
TOMORROW. SG
&&
.AVIATION...
UPR LOW CNTRD ABT 70 NM WSW OF KSFO MOVG SSE ALG CST TO NR KSAN BY
12Z WED. FOR CNTRL VLY...AREAS MVFR/IFR IN NMRS SHWRS WITH ISOLD
TSRA POSS. CONDS IMPVG FM N TO S THIS AFTN INTO EVE WITH VFR AFT
01Z. FOR CSTL/NRN INTR MTNS...LCL MVFR/IFR IN SHWRS TIL 00Z THEN
PDMT VFR. SN LVLS 030-040 AMSL. FOR W SLPS SIERNEV... WDSPRD MVFR
WITH AREAS IFR/LIFR IN SHWRS TIL 02Z THEN IMPVG CONDS FM N TO S. SN
LVLS 040-055 AMSL. S-SELY FLOW ALF VRG TO NLY ARND 06Z WED.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSGX 091716
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
915 AM PST TUE FEB 9 2010
.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM MOVING DOWN THE CALIFORNIA COAST WILL
TRACK SOUTHEAST ACROSS THE COASTAL WATERS TONIGHT AND TURN EAST
ACROSS NORTHERN BAJA CALIFORNIA EARLY WEDNESDAY AND THEN MOVE EAST
OF THE REGION BY WEDNESDAY EVENING. THIS WILL BRING PERIODS OF
PRECIPITATION THROUGH WEDNESDAY TO SOUTHWEST CALIFORNIA WITH A
CHANCE OF THUNDERSTORMS. SNOW LEVELS WILL LOWER TO NEAR 3000 FEET
LATE TONIGHT THROUGH EARLY WEDNESDAY. DRY AND GRADUALLY WARMER
THURSDAY THROUGH SATURDAY. STRONGER HIGH PRESSURE MAY BRING WARMING
TO ABOVE SEASONAL AVERAGES FOR SUNDAY THROUGH TUESDAY WITH WEAK
OFFSHORE WINDS POSSIBLE AT TIMES.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.SHORT TERM...TODAY THROUGH THURSDAY...
DIVERGENCE ALOFT AND RESULTING UPWARD VERTICAL MOTION AHEAD OF
APPROACHING COLD FRONT/UPPER LOW IS RESPONSIBLE FOR PRECIPITATION
STARTING EARLY THIS MORNING. RUC13 MODEL SHOWED OMEGA VALUES OF
-6 UBAR/SEC IN THE 850-500 MB LAYER OVER ORANGE COUNTY/SW SAN
BERNARDINO COUNTY THROUGH 0900 PST WITH SIMILAR VALUES DEVELOPING
OVER WESTERN RIVERSIDE/EASTERN SAN DIEGO COUNTY AFTER 1000 PST
AND INCREASING THEREAFTER. THE COLD FRONT...MARKED BY LINE OF 40 TO
50 DBZ ECHOES MOVING SOUTHEAST 22 KNOTS/25 MPH...EXTRAPOLATES TO THE
ORANGE COUNTY/AL COUNTY/SAN BERNARDINO COUNTY LINE AROUND 1 PM.
MODELS WERE IN GOOD AGREEMENT ON POSITION AND TIMING OF UPPER LOW...
UNTIL THE 09/12Z NAM RUN CAME IN. THIS MODEL IS NOW ABOUT 6 HOURS
SLOWER ON MOVING THE UPPER LOW SOUTHEAST FROM CURRENT POSITION OFF
CENTRAL CALIFORNIA COAST...ACROSS OR JUST OFFSHORE SAN DIEGO...AND
THEN EAST ACROSS NORTHERN GULF OF CALIFORNIA...OTHERWISE TRACK IS
CONSISTENT WITH OTHER MODEL RUNS. CONSENSUS IS THAT THIS SLOWER
MOVEMENT IS IN ERROR. SINCE CURRENT FORECAST TIMING IS ALIGNED WITH
FASTER GFS/ECMWF MODELS NO SIGNIFICANT CHANGES ANTICIPATED TO
FORECAST. COLD CORE...WITH 500 MB TEMPERATURES OF -30C AND 850 MB
TEMPERATURES -4C PASSES OVER SOUTHERN CALIFORNIA BIGHT AND SW
CALIFORNIA THIS EVENING/TONIGHT. GIVEN THESE VALUES AND 925 MB
TEMPERATURES ONLY COOLING TO 4 TO 6 DEGREES CELSIUS...LOWER LAPSE
RATES BECOME QUITE UNSTABLE THIS EVENING THROUGH EARLY WEDNESDAY
MORNING. MAY HAVE SEVERE WEATHER WATCHES OUT BEFORE THIS EVENT IS
OVER. FRO WEDNESDAY AFTERNOON SLOW WINDING DOWN OF SHOWER ACTIVITY
WEST OF MOUNTAINS AS CENTER OF LOW EXPECTED TO BE OVER NORTHERN GULF
OF CALIFORNIA BUT UPSLOPE FLOW AND WRAP AROUND MOISTURE WILL KEEP
RAIN AND SNOW GOING OVER DESERT AREAS/EAST AND NORTH SLOPES OF
MOUNTAINS. WEDNESDAY NIGHT THROUGH THURSDAY DRYING OUT UNDER THE
BUILDING HIGH PRESSURE RIDGE. MAY REINTRODUCE FROST FOR INLAND
VALLEYS WEDNESDAY NIGHT/THURSDAY MORNING AS WINDS FORECAST TO GO TO
NEAR CALM AND SKIES TO BE CLEAR. LOWER DESERT AREAS WILL LIKELY
STILL HAVE ENOUGH WIND TO KEEP FROST FROM FORMING THERE.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY...
GENERALLY FAIR AND DRY WITH A WARMING TREND THROUGH THIS PERIOD.
FLAT RIDGE FOR FRIDAY WITH TROUGH PASSING INLAND TO THE NORTH WILL
ALLOW MID/HIGH CLOUDS TO MOVE ACROSS THE FORECAST AREA. RIDGE
REBUILDS SATURDAY AND SUNDAY CREATING A FAVORABLE PATTERN FOR
LIGHT TO MODERATE OFFSHORE WINDS. RIDGE FLATTENS SOMEWHAT MONDAY AND
TUESDAY AS TROUGHS PASS INLAND WELL TO THE NORTH.
&&
.AVIATION...
091445Z...COLD FRONT MOVING THROUGH POINT CONCEPTION AREA THIS
MORNING SHOULD PASS THROUGH KSNA AROUND 18Z...KONT AROUND 19Z...AND
KSAN/KPSP AROUND 21Z. TRAILING EDGE OF THE FRONT SHOULD PASS THROUGH
ABOUT 2 HOURS LATER. MULTIPLE LAYERS OF BROKEN TO OVERCAST STRATOCU
OVER THE AREA AHEAD OF THE FRONT SHOULD BECOME MOSTLY OVERCAST
LAYERS BETWEEN 1500 AND 3000 FEET MSL. VISIBILITIES MAINLY 3 TO 5
MILES IN PRECIPITATION EXCEPT LOCALLY DOWN TO 1 MILE IN HEAVIER
PRECIPITATION. MOUNTAINS WILL BECOME MOSTLY OBSCURED BY NOONTIME.
BEHIND THE FRONT AND CONTINUING THROUGH THE NIGHT INTO WEDNESDAY
MORNING...MOSTLY BROKEN CU/TCU WITH BASES BETWEEN 2000 AND 3000 FEET
AND TOPS TO 10000 FEET MSL EXCEPT TOPS TO FL250 IN ISOLATED TSTMS.
HORTON
&&
.MARINE...
WATERSPOUT REPORTED IN PAST HOUR OFF SAN DIEGO COAST. POTENTIAL
EXISTS FOR ADDITIONAL WATERSPOUTS TO DEVELOP THROUGH WEDNESDAY
MORNING. SEE SPECIAL MARINE WARNINGS AND MARINE WEATHER STATEMENT.
&&
.HYDROLOGY...
LOWERED FLASH FLOOD THREAT FOR SAN BERNARDINO MOUNTAINS AFTER 10 PM
DUE TO LOWERING FREEZING LEVEL AND MOST PRECIPITATION BECOMING
FROZEN. RAINFALL RATES OF 0.50 TO 1.00 INCHES FROM 1 PM THROUGH 10 PM
POSSIBLE AS THIS IS PERIOD OF STRONGEST VERTICAL MOTION DUE TO
STRONG DIVERGENCE ALOFT FROM LEFT FRONT QUADRANT OF JET STREAM AND
FRONTAL LIFTING. MAY BE ABLE TO DROP FLASH FLOOD WATCH FOR ALL AREAS
AFTER THIS. UNLESS SLOWER NAM MODEL VERIFIES...CURRENT STORM
RAINFALL TOTALS IN QPFSAN FORECAST LOOK REASONABLE. MAIN DIFFERENCE
WOULD BE NORTH AND EAST SLOPES OF MOUNTAINS/LOWER DESERTS WOULD BE
SUBJECT TO WRAP AROUND MOISTURE FOR ANOTHER 6 HOURS...INTO WEDNESDAY
EVENING.
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH 6 AM PST WEDNESDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE
INLAND EMPIRE-SANTA ANA MOUNTAINS AND FOOTHILLS.
FLASH FLOOD WATCH THROUGH 10 PM TONIGHT BELOW 5000 FEET FOR
SAN BERNARDINO COUNTY MOUNTAINS EXCEPT CONTINUING THROUGH 1 AM
BELOW 4000 FEET.
WINTER WEATHER ADVISORY UNTIL 6 AM PST WEDNESDAY BELOW 6000
FEET FOR SAN BERNARDINO COUNTY MOUNTAINS.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY ABOVE 6000 FEET FOR RIVERSIDE COUNTY MOUNTAINS-
SAN BERNARDINO COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY BELOW 6000 FEET FOR RIVERSIDE COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY ABOVE 3500 FEET FOR APPLE AND LUCERNE VALLEYS-.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM PST
WEDNESDAY ABOVE 3500 FEET FOR SANTA ANA MOUNTAINS.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 6 AM PST
WEDNESDAY FOR SAN DIEGO COUNTY MOUNTAINS.
SPECIAL WEATHER STATEMENT TO SUMMARIZE ABOVE AND COVER OTHER
EFFECTS IN REMAINING ZONES
PZ...MARINE WEATHER STATEMENT BOTH INNER AND OUTER COASTAL
WATERS FOR THREAT OF THUNDERSTORMS AND WATERSPOUTS THROUGH
WEDNESDAY MORNING.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KHNX 091700
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
900 AM PST TUE FEB 9 2010
.SYNOPSIS...
A PACIFIC STORM WILL MOVE THROUGH THE CENTRAL CALIFORNIA INTERIOR
TODAY THROUGH WEDNESDAY MORNING. THE HEAVIEST PRECIPITATION WILL BE
TONIGHT...WITH MOUNTAIN SNOW DOWN TO THE PASS LEVEL IN KERN COUNTY.
PATCHY FOG WILL RETURN THURSDAY MORNING A HIGH PRESSURE BUILDS BACK
OVER THE REGION.
&&
.DISCUSSION...THE UPPER LOW IS CURRENTLY ROTATING JUST TO THE WSW
OF SFO BASED ON RADAR. THE BAROCLINIC BAND OF MODERATE PRECIP IS
CURRENTLY MOVING THRU THE SJV AND WEAKENING AS IT DOES. THIS IS A
RATHER TYPICAL SCENARIO FOR A COAST HUGGER...WITH PRECIP MAINLY
DISSIPATING BEFORE IT REACHES HIGHER ELEVATIONS OF THE SRN SIERRA.
IT WILL BE A CLOSE CALL IF ANYTHING SIGNIFICANT HAPPENS IN THE
ADVISORY AREA OF TULARE COUNTY.
HOWEVER...UPGRADED THE WSW TO A WARNING FOR KERN COUNTY AS THIS IS
AN EXCELLENT PATTERN FOR AN UPSLOPE EVENT TO DEVELOP OVER THE
TEHACHAPI MOUNTAINS THIS AFTERNOON AND EVENING. THE FIRST BAND OF
PRECIP WILL REACH THE AREA THIS MORNING AND SNOW LEVELS WILL
GRADUALLY LOWER. THEN AS THE UPPER LOW SLIDES BY TO THE WEST...AN
EAST FLOW WILL DEVELOP. THIS OFTEN CREATES AN UPSLOPE FLOW WITH
THE DEFORMATION ZONE ON THE NORTH SIDE OF THE LOW...WHICH CAN
RESULT IN VERY HEAVY SNOW IN THE CUDDY VALLEY...FRAZIER
PARK...TEJON PASS AREAS. SOMETIMES EVEN AS FAR EAST AS TEHACHAPI.
COULD SEE UPWARDS OF A FOOT OF SNOW AROUND FRAZIER PARK...IF NOT
MORE.
&&
.FROM PREV DISCUSSION... /ISSUED 225 AM PST TUE FEB 9 2010/
FOR THE SAN JOAQUIN VALLEY AND THE ADJACENT FOOTHILLS...THE 06Z
NAM-12 HAS SURFACE COMPUTED CAPES UP TO 420 JOULES/KG OVER WESTERN
FRESNO COUNTY AT 21Z...AND ALSO OVER THE GRAPEVINE. SURFACE
COMPUTED LIFTED INDEXES ARE NEGATIVE OVER MOST OF THE HANFORD
WARNING/ FORECAST AREA...AND EVEN WITH THE COLDEST 500-MN AIR OFF
THE COAST OF SAN LUIS OBISPO COUNTY...500-MB TEMPERATURES OVER THE
HANFORD FORECAST AREA ARE AROUND -27 C. HOWEVER...THE NAM-12 KEEPS
THE 300-MB JET WELL OFFSHORE UNTIL TONIGHT...WHEN IT MOVES OVER
THE CENTRAL CALIFORNIA INTERIOR AFTER 06Z WEDNESDAY.
SPC HAS MOST OF THE REGION UNDER A GENERAL RISK OF THUNDERSTORMS...
SO HAVE PENCILED IN AFTERNOON THUNDERSTORMS OVER THE CENTRAL AND
SOUTHERN SAN JOAQUIN VALLEY... THE SOUTHERN SIERRA NEVADA
FOOTHILLS...AND THE NORTH SLOPES OF THE TEHACHAPI MOUNTAINS. WILL
ISSUE A SPECIAL WEATHER STATEMENT ON THE CONVECTIVE POTENTIAL.
AS THE UPPER-LEVEL TROUGH MOVES INLAND WEDNESDAY...AN EAST-PACIFIC
RIDGE WILL BUILD INTO CALIFORNIA BEHIND IT. WITH A STABLE AIRMASS
ALOFT AND A SUPPLY OF LOW-LEVEL MOISTURE...CONDITIONS WILL BE RIGHT
FOR PATCHY FOG DEVELOPMENT OVER THE CENTRAL AND SOUTHERN SAN JOAQUIN
VALLEY WEDNESDAY NIGHT/THURSDAY MORNING.
THE NAM-12 BRINGS A WEAK UPPER-LEVEL TROUGH INTO CALIFORNIA FRIDAY.
THE 12Z UKMET SUPPORTS THIS SOLUTION...BUT THE 00Z ECMWF AND 06Z GFS
HAVE A NEARLY-ZONAL FLOW OVER THE STATE. HAVE KEPT THE CHANCE POPS
OVER THE NORTHERN HALF OF THE HANFORD WARNING/FORECAST AREA FOR
THURSDAY NIGHT AND FRIDAY...BUT CONFIDENCE IS LOWER IN THIS SOLUTION.
BEYOND FRIDAY...THE MEDIUM-RANGE MODELS HAVE RIDGING OVER THE EAST
PACIFIC AND CALIFORNIA THROUGH THE REMAINDER OF THE FORECAST PERIOD.
EXPECT DRY WEATHER TO PREVAIL OVER THE WEEKEND INTO THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...VFR EXCEPT AREAS MVFR DUE TO LOWERING
CEILINGS AND VISIBILITY IN -RA/BR THROUGH 12Z WEDNESDAY. IN THE SIERRA
NEVADA AND TEHACHAPI MOUNTAINS...MVFR AND LCL IFR CEILINGS AND MOUNTAIN
OBSCURATIONS WITH RA/SN. IN THE KERN COUNTY DESERT...VFR EXCEPT LCL
MVFR IN RA POSSIBLY MIXED WITH -SN AFTER 04Z WEDNESDAY.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 10 AM PST
WEDNESDAY CAZ097.
WINTER STORM WARNING FROM NOON TODAY TO 10 AM PST WEDNESDAY
CAZ095.
&&
$$
PUBLIC...BINGHAM
AVN/FW...GREISS
SYNOPSIS...WP
WEATHER.GOV/HANFORD
000
FXUS66 KEKA 091524 AAA
AFDEKA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE EUREKA CA
725 AM PST TUE FEB 9 2010
.SYNOPSIS...SHOWERS WILL COME TO AN END THIS MORNING AS HIGH
PRESSURE BUILDS OVER THE REGION. MORE PRECIPITATION IS EXPECTED
THURSDAY INTO FRIDAY AS ANOTHER FRONT PUSHES ASHORE.
&&
.UPDATE...TEXT AND GRID UPDATES FORTHCOMING. LOW PRESSURE HAS SUNK
SOUTH OVER THE BAY AREA WITH WRAP AROUND MOISTURE LINGERING OVER
MENDOCINO COUNTY. FARTHER NORTH...SKIES HAVE CLEARED AND EXPECT A
PARTLY CLOUDY DAY WITH NO CHANCE FOR RAIN FOR HUMBOLDT AND DEL NORTE
COUNTY. THUS...FORECAST PACKAGE UPDATES WILL INCLUDE LESS SKY COVER
FOR TODAY AS WELL AS A DOWNWARD ADJUSTMENT IN POPS. BURGER
&&
.DISCUSSION...WATER VAPOR IMAGERY CLEARLY SHOWS LOW PRESSURE JUST
OFF THE CALIFORNIA COAST. RADAR SHOWS SCATTERED SHOWERS MOSTLY
SOUTH OF CAPE MENDOCINO AT THIS TIME. THIS IS A LITTLE FURTHER TO
THE WEST THAN EXPECTED. HOWEVER, THE BENEFITS ARE LESS
PRECIPITATION AND SNOW LEVELS ABOUT 1000 FT HIGHER SINCE THE LARGE
AREA OF COLD AIR IS MOSTLY OFFSHORE. THUNDERSTORM ACTIVITY IS
MINIMAL, BUT LEFT MENTION OF IT IN THE SOUTHERN WATERS FORECAST
FOR THE MORNING HOURS SINCE MODELS STILL SHOW SOME INSTABILITY.
THE LOW AND ITS PRECIPITATION WILL CONTINUE TO MOVE TO THE SOUTH
TODAY. SHOWERS WILL DIMINISH BY THE AFTERNOON AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS OVER THE AREA. DRY WEATHER IS EXPECTED
TONIGHT THROUGH WEDNESDAY NIGHT. MORE RAIN WILL THREATEN THE AREA
IN ADVANCE OF THE NEXT FRONT. THE MAIN THREAT OF PRECIPITATION
WILL BEGIN LATE WEDNESDAY NIGHT. THE HIGHEST POPS WILL BE NEAR THE
CA/OR BORDER AND GRADUALLY DECLINE FURTHER SOUTH. HOWEVER, RAIN
WILL OVERSPREAD THE ENTIRE AREA THURSDAY INTO FRIDAY AS THE FRONT
MOVES ONSHORE. STROZ
&&
.AVIATION...AN APPROACHING TROUGH ALOFT WILL CONTINUE TO GENERATE
WEAK INSTABILITY AND SCATTERED SHOWERS THROUGH 11 AM PST. SHOWER
ACTIVITY WILL DIMINISH THIS AFTERNOON AND EVENING AS THE LOW MOVES
SOUTHWARD AWAY FROM THE AREA. LOW CEILINGS AND ISOLATED VSBY
RESTRICTIONS IN BR AND SHRA SHOULD IMPROVE THIS AFTERNOON. DJB
&&
.MARINE...HIGH PRES OVER THE E PAC WILL CONTINUE TO PRODUCE LIGHT
TO MODERATE NORTHERLY WINDS THROUGH TONIGHT. A WEAK LOW WILL
APPROACH ON WED AND BRING A THREAT OF GALE FORCE WINDS ON THU.
LARGE WESTERLY SWELL GENERATED FROM THIS STORM WILL BUILD ON FRI
AND REMAIN HIGH THROUGH SAT. DJB
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS65 KPSR 091324 AAB
AFDPSR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
624 AM MST TUE FEB 9 2010
.UPDATE...
MINOR UPDATE TO THE FORECAST FOR TODAY. APPEARS THAT THE STRONG
FORCING WITH THE INCOMING SYSTEM IS CAUSING SOME ISOLATED SHOWERS TO
DEVELOP ACROSS SRN NV AND SRN CA. THIS IS LIKELY IN RESPONSE TO A
LIFTING WARM FRONT /SRN NV/ AND AN INCOMING PV ANOMALY ON THE
STRENGTHENING JET OVERHEAD. WITH THE PV ANOMALY FORECAST TO MOVE
THROUGH THE WRN CWA THIS MORNING I ADDED SOME SLIGHT CHANCE POPS TO
THAT AREA. KEPT THE LOW POPS INTO THE AFTN HOURS AS SOLAR HEATING
COULD LEAD TO A FEW CONVECTIVE SHOWERS. NO OTHER UPDATES.
&&
.SYNOPSIS...
EXPECT AN INCREASE IN MAINLY HIGH CLOUDS TODAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW
SHOWERS...AS WELL AS A SLIGHT CHANCE OF A THUNDERSTORM...WILL OCCUR
OVER FAR SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY
TONIGHT INTO EARLY WEDNESDAY...AND MAINLY OVER SOUTHWEST AND SOUTH-
CENTRAL ARIZONA WEDNESDAY. DRIER CONDITIONS WILL PREVAIL THURSDAY AS
THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL.
WARMER WEATHER WILL SLOWLY RETURN HEADING INTO THE WEEKEND WITH
ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
IMPRESSIVE LOW IS QUICKLY DIVING ALONG THE NRN CA COAST THIS
MORNING...PRETTY MUCH AS EXPECTED. SOUTHERN BRANCH OF THE JET IS
ALSO RESPONDING TO THE INCOMING LOW AS CAN BE SEEN WITH THE FLARE-UP
IN PWAT AND IR IMAGERY...AGAIN AS EXPECTED.
00Z MODELS APPEAR TO HAVE A PRETTY GOOD HANDLE ON THE SYSTEM AND
REMAIN IN GENERALLY GOOD AGREEMENT AS IT TRAVERSES OUR CWA THOUGH
THERE REMAIN MINOR IMPORTANT DIFFERENCES. MODELS HAVE TAKEN A
NOTICEABLE SW JOG WITH THE SYSTEM...NOT SURPRISING GIVEN IT IS A BIT
COLDER AND STRONGER THEN EXPECTED. IT NOW APPEARS THE STRONGEST
FORCING WILL IMPACT OUR WRN CWA...THEN SWING SOUTH AND EAST OF OUR
AREA. OVERALL SYSTEM REMAINS VERY IMPRESSIVE WITH IT/S FORCING
FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE IN SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S ON THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
KPHX AND KIWA...
LIGHT WINDS FROM THE EAST THIS MORNING ARE EXPECTED TO BECOME
VARIABLE AFTER 2000 TO 2200 GMT THIS AFTERNOON...THEN FROM THE EAST
AGAIN AFTER ABOUT 0400 GMT AT KIWA AND 0800 GMT AT KPHX TONIGHT.
HIGH CLOUDINESS IS EXPECTED TO INCREASE FROM THE SOUTHWEST BY THIS
AFTERNOON AND TONIGHT WITH A FEW TO SCATTERED CLOUDS NEAR 7 AND 14
THOUSAND FEET.
KIPL AND KBLH...
LIGHT AND VARIABLE WINDS ARE EXPECTED THIS MORNING BECOMING FROM THE
SOUTH AROUND 10 KNOTS LATE THIS MORNING AND/OR THIS AFTERNOON...THEN
FROM THE SOUTHWEST AND WEST TONIGHT. INCREASING AND LOWERING
CLOUDINESS IS EXPECTED THROUGH THE PERIOD WITH CEILINGS LOWERING TO
6 THOUSAND FEET AFTER 0800 GMT TONIGHT AND AS LOW AS 4 THOUSAND FEET
AFTER 1000 GMT WITH VISIBILITY DROPPING TO NEAR 5 MILES IN SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KSGX 091238
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
440 AM PST TUE FEB 9 2010
.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM FROM THE NORTHWEST WILL TRACK ACROSS
NORTHERN BAJA TONIGHT AND MOVE SLOWLY EAST ON WEDNESDAY. THIS WILL
BRING PERIODS OF PRECIPITATION THROUGH EARLY WEDNESDAY WITH A CHANCE
OF THUNDERSTORMS AND WITH SNOW LEVELS LOWERING TO NEAR 3000 FEET
LATE TONIGHT THROUGH EARLY WEDNESDAY. DRY AND GRADUALLY WARMER
THURSDAY THROUGH SATURDAY. STRONGER HIGH PRESSURE MAY BRING WARMING
TO ABOVE SEASONAL AVERAGES FOR SUNDAY THROUGH TUESDAY WITH WEAK
OFFSHORE WINDS POSSIBLE AT TIMES.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH THURSDAY)...
LOTS OF LAST MINUTE ADJUSTMENTS TO THE FORECAST FOR THE TODAY PERIOD
AND FOR ASSOCIATED WATCHES...WARNINGS...AND ADVISORIES. A
COLD...COMPACT LOW PRESSURE SYSTEM IS MOVING QUICKLY SOUTHWARD JUST
OFF THE CENTRAL CALIFORNIA COAST. THIS LOW IS EXPECTED TO TRACK
INLAND ACROSS NORTHERN BAJA TONIGHT. THE MAIN ADJUSTMENT TO THE
FORECAST FOR TODAY WAS TO INCREASE THE AMOUNT OF PREFRONTAL
PRECIPITATION IN THE DIFLUENT AREA AHEAD OF THE UPPER TROUGH. THIS
ISN`T BEING HANDLED WELL BY ANY OF THE MODELS. EXPERIMENTAL RADAR
BASED SNOW LEVEL GRIDS AND SURFACE REPORTS SUGGEST AN INITIAL SNOW
LEVEL NEAR 4500 TO 5000 FEET THIS MORNING. THIS MAY LOWER SLIGHTLY
DURING THE AFTERNOON WITH THE BIGGER DROP LATE THIS AFTERNOON INTO
THE EVENING WITH THE PASSAGE OF THE COLD FRONT. SNOW LEVELS ARE
EXPECTED TO LOWER TO 3000 TO 3500 FEET FOR LATE TONIGHT INTO
WEDNESDAY MORNING. THE CURRENT TRACK OF THE UPPER LOW SHOULD KEEP
SNOW LEVELS FROM FALLING MUCH LOWER. WARNING THRESHOLD SNOW AMOUNTS
ARE POSSIBLE IN THE MOUNTAINS ABOVE 6000 FEET AND ADVISORY THRESHOLD
AMOUNTS BETWEEN 4000 AND 6000 FEET AND IN THE UPPER DESERTS ABOVE
4000 FEET.
LIGHT TO LOCALLY MODERATE PRECIPITATION WILL INCREASE IN COVERAGE
TODAY IN ADVANCE OF A COLD...COMPACT LOW PRESSURE SYSTEM MOVING
SOUTHWARD OFF THE CENTRAL CALIFORNIA COAST. THE ASSOCIATED COLD
FRONT IS EXPECTED TO MORE THROUGH SOUTHWEST CALIFORNIA LATE THIS
AFTERNOON AND THIS EVENING WITH NUMEROUS SHOWERS CONTINUING
OVERNIGHT AND DECREASING WEDNESDAY. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WITH SMALL HAIL TONIGHT THROUGH EARLY WEDNESDAY.
RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM NEAR 1 INCH AT THE COAST
TO 1.5 TO 2.5 INCHES ON THE COASTAL MOUNTAIN SLOPES WITH LOCAL
AMOUNTS TO 3.5 INCHES. AMOUNTS IN THE DESERTS OF ONE QUARTER TO ONE
HALF INCH.
PERIODS OF HIGH INTENSITY PRECIPITATION ARE POSSIBLE TONIGHT THROUGH
EARLY WEDNESDAY WHICH COULD INCREASE THE RUNOFF AND FLOODING
POTENTIAL...ESPECIALLY FOR NORTHERN AREAS NEARLY SATURATED FROM
RAINFALL FROM LAST FRIDAY NIGHT AND SATURDAY. A FLASH FLOOD WATCH IS
POSTED FOR THESE AREAS THROUGH TONIGHT.
SHOWERS ARE EXPECTED TO END WEDNESDAY. DRY WITH SLOW WARMING FOR
THURSDAY.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
DRY THROUGH THE PERIOD WITH BUILDING HIGH PRESSURE. TEMPERATURES
WILL WARM TO ABOVE SEASONAL AVERAGES FOR SUNDAY THROUGH EARLY NEXT
WEEK WITH WEAK OFFSHORE FLOW AT TIMES. LOW PRESSURE MAY BEGIN TO
UNDERCUT THE WEST COAST HIGH PRESSURE TOWARD THE END OF NEXT WEEK.
&&
.AVIATION...
091030Z...MULTIPLE OVERCAST LAYERS AT OR ABOVE FL040 HAVE ALREADY
DEVELOPED OVER THE AREA IN ADVANCE OF AN APPROACHING PACIFIC TROUGH.
SCATTERED LIGHT SHOWERS HAVE BROKEN OUT OVER THE SAN BERNARDINO
MOUNTAINS THIS EARLY MORNING. CLOUDS WILL GRADUALLY THICKEN AND
LOWER DURING THE DAY. 1500 FT MSL BASES AND HEAVIER RAIN WILL BEGIN
MOVING INTO ORANGE COUNTY AROUND 21Z...AND SPREAD SE THROUGH THE
AREA THROUGH THE AFTERNOON AND EVENING...REACHING KSAN BY 0Z. THE
TROUGH WILL BE SLOW MOVING...SO LOW CEILINGS...RAIN AND A CHANCE OF
THUNDERSTORMS WILL CONTINUE THROUGH 18Z WED. THE SNOW LEVEL WILL BE
AROUND 5000 FEET TODAY...THEN LOWER TO 3500 FEET BY 12 WED.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR ORANGE COUNTY
COASTAL AREAS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SANTA ANA
MOUNTAINS AND FOOTHILLS.
WINTER WEATHER ADVISORY UNTIL 2 PM PST THIS AFTERNOON FOR SAN
BERNARDINO COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY FOR APPLE AND LUCERNE VALLEYS-RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 6 AM PST
WEDNESDAY FOR RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO
COUNTY MOUNTAINS.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 6 AM PST
WEDNESDAY FOR SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MACKECHNIE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KSTO 091207
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
405 AM PST TUE FEB 9 2010
.DISCUSSION...
CLOSED UPPER LOW CURRENTLY NEAR 38N 124W WILL BE THE PRIMARY WEATHER
PRODUCER OVER NORTHERN CALIFORNIA TODAY. SEVERAL BANDS OF SHOWERS
HAVE BEEN SPREADING INLAND DURING THE OVERNIGHT HOURS. NOT MUCH OF A
MOISTURE PLUME TO SPEAK OF...AND GENERALLY PRECIPITATION TOTALS HAVE
BEEN LIGHT THUS FAR WITH ONLY A FEW HUNDREDTHS FOR MOST VALLEY
LOCATIONS TO A FEW TENTHS FOR THE HIGHER ELEVATIONS. SNOW LEVELS ARE
RUNNING AT AROUND 3000 FEET TOWARDS THE NORTHERN MOUNTAINS AND
AROUND 4000 FEET TOWARDS THE WESTERN SLOPES OF THE SIERRA.
TEMPERATURES EARLY THIS MORNING ARE RUNNING SEVERAL DEGREES WARMER
THAN 24 HOURS AGO...THE EXCEPTION BEING TOWARDS THE HIGHER
ELEVATIONS WHERE THE COLDER AIRMASS HAS BROUGHT TEMPERATURES DOWN A
FEW DEGREES.
IR SATELLITE INDICATES A SECONDARY SHORTWAVE BAND WITH COOLING CLOUD
TOPS MOVING INLAND EARLY THIS MORNING. THIS SHOULD BRING ANOTHER
ROUND OF SHOWERS TO THE FORECAST AREA BY MID MORNING. MODELS IN
GENERAL HAVE BEEN HANDLING THIS SYSTEM RATHER POORLY. A FEW OF THE
LIMITING FACTORS WITH THIS SYSTEM INCLUDE THE AFOREMENTIONED LACK OF
A SIGNIFICANT MOISTURE PLUME...THE SPEED AT WHICH THE SYSTEM IS
DIVING SOUTHWARD...AND ITS DISTANCE OFFSHORE. EXPECTING THAT
PRECIPITATION SHOULD BEGIN SHUTTING OFF TOWARDS THE NORTHERN SAC
VALLEY AND SURROUNDING MOUNTAINS WITH BY MID-MORNING...AND DRYING
TOWARDS THE REST OF THE CWA BY MID-AFTERNOON. MODEST INSTABILITY
WITH THE COLD POOL ALOFT MAY TRIGGER A FEW THUNDERSTORMS IN THE
SOUTHWESTERN PORTIONS OF THE CWA TODAY...THOUGH THE BEST CHANCES
WILL REMAIN OFFSHORE.
DECREASING CLOUDS ARE EXPECTED THIS EVENING AS THE UPPER LOW TRACKS
SOUTHWARD AND SHORTWAVE RIDGING BUILDS OVER NORCAL. CLEARING SKIES
AND REMNANTS OF THE COLD AIRMASS SHOULD ALLOW FOR GOOD RADIATIONAL
COOLING TONIGHT...OVERNIGHT LOWS ARE EXPECTED IN THE 30S THROUGH THE
VALLEY AND IN THE 10S TO 20S OVER THE HIGH COUNTRY. WITH PERHAPS A
LIGHT NORTHERLY BREEZE THROUGH THE VALLEY...NOT EXPECTING MUCH IN
THE WAY OF FOG DEVELOPMENT TONIGHT.
PLEASANT WEATHER IN STORE FOR WEDNESDAY AS RIDGING SHIFTS OVERHEAD.
TEMPERATURES IN THE UPPER 50S TO PERHAPS LOWER 60S WILL BE
ATTAINABLE IN THE VALLEY WITH 40S AND 50S OVER THE HIGHER
ELEVATIONS.
THE UPPER RIDGE WILL QUICKLY SHIFT EASTWARD AS THE NEXT SERIES OF
TROUGHS APPROACH THE AREA. THE FIRST SHORTWAVE SHOULD MOVE TOWARDS
THE PACIFIC NORTHWEST THURSDAY WITH ONLY A CHANCE OF SOME WARM
ADVECTION PRECIPITATION TOWARDS THE NORTHERN MOUNTAINS. A SECOND
WAVE WILL APPROACH NORTHERN CALIFORNIA LATE THURSDAY INTO
FRIDAY...PROVIDING A BETTER CHANCE OF PRECIPITATION TO THE AREA.
SNOW LEVELS SHOULD BE SLIGHTLY HIGHER THAN THE LAST FEW STORMS...IN
THE 3000 TO 4000 RANGE TOWARDS THE NORTHERN MOUNTAINS AND 4000-5500
FEET TOWARDS THE NORTHERN SIERRA. DANG
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)...
AFTER THE WEATHER SYSTEM MOVES THROUGH INTERIOR NORCAL ON FRIDAY...
THE WEEKEND SHOULD GENERALLY BRING A BREAK IN PRECIPITATION TO MOST
OF THE AREA...ALTHOUGH THERE IS THE PROBABILITY OF STRATUS/FOG
RETURNING TO THE INTERIOR AND MTN VLYS DURING THE MORNINGS. THE
MEDIUM RANGE MODELS INDICATE AN AMPLIFICATION OF A POSITIVELY TILTED
RIDGE ALONG THE COAST AND INTO THE NRN ROCKYS WHILE A GULF OF AK
TROF APPROACHES THE W COAST FOR THE WEEKEND. THIS WILL RESULT IN
SEASONABLY MILD TEMPS IN THE INTERIOR OF NORCAL AS TEMPS SHOULD BE
NEAR OF SLIGHTLY ABOVE NORMAL...UNLESS THE FOG IS SLOW TO DISSIPATE
IN SOME AREAS DURING THE DAYLIGHT HOURS. DURING THE DAY ON SUN AND
INTO EARLY NEXT WEEK...A COUPLE OF UPPER LEVEL TROFS ARE FORECAST TO
MOVE INTO THE PAC NW/B.C. AREAS...DRAGGING A COUPLE OF WEAK FRONTS
ACROSS NORCAL...POSSIBLY BRINGING SOME PCPN MAINLY TO THE NRN MTN
AND/OR NRN INTERIOR VLY AREAS. WE ARE FAVORING THE GFS/ECMWF OVER
THE GEM AS THE SHORT WAVE ENERGY IS FORECAST TO LIFT NEWD ACROSS THE
PAC NW AND B.C. AREAS WEAKENING THE FRONT AND RESULTING IN LESS PCPN
IN NORCAL THAN WHAT IS FORECAST BY THE GEM WITH THE SUN/MON SYSTEM.
ON TUE...THE MODELS ARE TRENDING DRIER AS A DEEPENING ERN PAC TROF
AMPLIFIES THE DOWNSTREAM RIDGE ALONG THE COAST. JHM
&&
.AVIATION...
NUMEROUS SHOWERS THIS MORNING AS UPPER LEVEL LOW PRESSURE SYSTEM
MOVES SEWD ALONG THE CA COAST. BY AFTERNOON...THE UPPER LOW IS
FORECAST TO BE S OF MRY BAY AREA...AND SHOWERS SHOULD BEGIN TO
DIMINISH FROM N TO S. ISOLATED THUNDERSTORMS HAVE BEEN NOTED OFF THE
COAST...AND THERE IS A CHANCE THAT ISOLATED THUNDERSTORMS MAY
MOVE/DEVELOP ALONG THE COAST AND INTO THE WRN PORTION OF THE SRN SAC
OR NRN SAN JOAQUIN VLY DURING THE LATE MORNING OR AFTERNOON HRS.
WIDESPREAD MVFR CIGS AND/OR VSBYS EXPECTED IN SHOWERS IN THE VALLEY
AT TIMES THIS MORNING...WITH IMPROVING CIGS OVER THE NRN SAC VLY
DURING THE AFTERNOON. OVER SIERNEV...WIDESPREAD IFR WX DUE TO
CIGS/VSBYS/PCPN WITH SNOW LEVEL LOWERING TO NEAR 3000 FEET NRN MTNS
AND 3500 TO 4000 FEET ACROSS THE SIERNEV.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KMTR 091159
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
400 AM PST TUE FEB 9 2010
.DISCUSSION...AS OF 3:42 AM PST TUESDAY...SHOWERS THROUGH
TONIGHT WITH SNOW LEVELS DOWN TO 3000 FEET IN MONTEREY COUNTY.
KMUX DOPPLER RADAR IS INDICATING WIDE SPREAD SHOWERS ACROSS THE CWA
THIS MORNING. THE LATEST SATELLITE WATER VAPOUR IMAGE IS SHOWING
AN UPPER-LEVEL LOW PRESSURE SYSTEM SLIDING DO SOUTH ALONG THE CENTRAL
COAST. THIS LOW IS TRIGGERING THE SHOWERS AND WILL BRING SNOW
LEVELS DOWN TO 3000 FEET IN MONTEREY COUNTY. SNOW WILL BE POSSIBLE
ELSEWHERE WITH SNOW LEVELS CLOSER TO 4000 TO 5000 FEET.
MODEL SOLUTIONS HAVE SHIFTED THE POSITION OF THE UPPER LEVEL LOW
SIGNIFICANTLY WEST COMPARED TO PREVIOUS MODEL RUNS. THIS HAS LEAD TO
THE DECISION TO REMOVE THE WINTER WEATHER ADVISORY FROM THE EAST BAY
HILLS AND DIABLO RANGE AS WELL AS THE SANTA CRUZ MOUNTAINS.
THIS SHIFT TO A MORE WESTERLY ROUTE WILL PROMOTE HIGHER SNOW LEVELS
OVER THESE AREAS WITH SNOW LEVELS EXPECTED TO BE ABOVE 4000 FEET
WHILE PRECIPITATION IS ACTUALLY OCCURRING. CURRENTLY BEN LOMOND
LOCATED AT 2600 IS AT 39 DEGREES F AND MT DIABLO LOCATED AT 3800
FEET IS AROUND 36 DEGREES F. ADDITIONALLY... THE BODEGA BAY WIND
PROFILER IS INDICATING A SNOW LEVEL OF AROUND 5000 FEET.
AS MENTIONED ABOVE THE WINTER WEATHER ADVISORY HAS BEEN DROPPED
OVER MOST AREAS WITH THE EXCEPTION OF THE SANTA LUCIA MOUNTAINS AND
LOS PADRES NATIONAL FOREST. ACCORDING TO THE 0900 UTC RUC ANALYSIS
THE UPPER LEVEL LOW COULD BRUSH BY THIS AREA DROPPING SNOW LEVELS
TO 3000 FEET AND LOCALLY TO 2500 FEET DURING PERIODS WHEN
PRECIPITATION WOULD BE FALLING. THIS WILL RESULT IN SNOW
ACCUMULATIONS OF 3 TO 5 INCHES OVER THE NEXT 12 HOURS PROMPTING A
WINTER WEATHER ADVISORY FOR ELEVATIONS GREATER THAN 3000 FEET IN
THIS AREA.
ONCE THIS LOW PASSES SOUTH A RIDGE OF HIGH PRESSURE WILL BUILD OVER
THE EASTERN PACIFIC LEAVING THE AREA DRY THROUGH THURSDAY MORNING.
CURRENT MODEL SOLUTIONS SLIDE A WEAK SHORT WAVE ACROSS THE NORTHBAY
AREA THURSDAY RESULTING IN INCREASED CLOUDS AND A CHANCE OF RAIN
WHICH IS EXPECTED TO SLIDE SOUTH FRIDAY MORNING.
AFTER FRIDAY...A RIDGE DEVELOPS OVER CALIFORNIA KEEPING THE STORM
TRACK JUST NORTH OF THE REGION. AT THIS POINT WILL NOT MENTION RAIN
IN THE FORECAST FOR THE WEEKEND...BUT WILL REINTRODUCE THE
SLIM POSSIBILITY OF RAIN SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 4:00 AM TUESDAY...UPPER LOW JUST WEST OF KSFO AT
POST TIME. SURFACE BOUNDARY HAS ALREADY MOVED THROUGH AND WINDS AT
KSFO AND KOAK HAVE ALREADY SHIFTED TO WESTERLY...WITH A NOTED WIND
SHIFT ALREADY NOTED AT THE BUOYS AND COASTAL SITES. EXPECT KSJC TO
SHIFT SHORTLY WITH KNUQ ALREADY WSW. SHOWERS ARE NUMEROUS AS OF 12Z
WITH PEAK IN AREAL COVERAGE EXPECTED BETWEEN NOW AND 18Z...THEN
RAPIDLY DECREASING THROUGH MIDDAY AND AFTERNOON HOURS.
VICINITY OF KSFO...WEST WINDS TODAY MAINLY UNDER 12 KT. LIGHT RAIN
THIS MORNING WITH CIGS IN THE 3-5K RANGE...DECREASING RAPIDLY AFTER
18Z AS THE UPPER LOW SHIFTS SOUTH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO...BUT MORE WIDESPREAD PRECIP
EXPECTED OVER THE SOUTH END OF THE BAY DUE TO CLOSER PROXIMITY TO THE
UPPER LOW THIS MORNING.
MRY BAY AREA TERMINALS...WINDS HAVE SHIFT WESTERLY AT KMRY AND KSNS.
SHOWERS WILL CONTINUE TO MOVE ONSHORE THIS MORNING AND LINGER A
LITTLE LONGER AT THESE TERMINALS THROUGH MIDDAY AS UPPER LOW SHIFT
SOUTHWARD DOWN THE COAST. LOOKS PRETTY CLEAR THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...WINTER WEATHER ADVISORY ABOVE 3000 FEET FOR
SANTA LUCIA MTNS AND LOS PADRES NATIONAL FOREST
STARTING 6AM THIS MORNING.
.SCA...FOR ALL COASTAL WATERS AND MONTEREY BAY
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: RWW
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 091142
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
342 AM PST TUE FEB 9 2010
.DISCUSSION...AS OF 3:42 AM PST TUESDAY...SHOWERS THROUGH
TONIGHT WITH SNOW LEVELS DOWN TO 3000 FEET IN MONTEREY COUNTY.
KMUX DOPPLER RADAR IS INDICATING WIDE SPREAD SHOWERS ACROSS THE CWA
THIS MORNING. THE LATEST SATELLITE WATER VAPOUR IMAGE IS SHOWING
AN UPPER-LEVEL LOW PRESSURE SYSTEM SLIDING DO SOUTH ALONG THE CENTRAL
COAST. THIS LOW IS TRIGGERING THE SHOWERS AND WILL BRING SNOW
LEVELS DOWN TO 3000 FEET IN MONTEREY COUNTY. SNOW WILL BE POSSIBLE
ELSEWHERE WITH SNOW LEVELS CLOSER TO 4000 TO 5000 FEET.
MODEL SOLUTIONS HAVE SHIFTED THE POSITION OF THE UPPER LEVEL LOW
SIGNIFICANTLY WEST COMPARED PREVIOUS MODEL RUNS. THIS HAS LEAD TO THE
DECISION TO REMOVE THE WINTER WEATHER ADVISORY FROM THE EAST BAY
HILLS AND DIABLO RANGE AS WELL AS THE SANTA CRUZ AND MOUNTAINS.
THIS SHIFT TO A MORE WESTERLY ROUTE WILL PROMOTE HIGHER SNOW LEVELS
OVER THESE AREAS WITH SNOW LEVELS EXPECTED TO BE ABOVE 4000 FEET
WHILE PRECIPITATION IS ACTUALLY OCCURRING. CURRENTLY BEN LOMOND
LOCATED AT 2600 IS AT 39 DEGREES F AND MT DIABLO LOCATED AT 3800
FEET IS AROUND 36 DEGREES F. ADDITIONALLY... THE BODEGA BAY WIND
PROFILER IS INDICATING A SNOW LEVEL OF AROUND 1000 FEET.
AS AFORE MENTIONED THE WINTER WEATHER ADVISORY HAS BEEN DROPPED
OVER MOST AREAS WITH THE EXCEPTION OF THE SANTA LUCIA MOUNTAINS AND
LOS PADRES NATIONAL FOREST. ACCORDING TO THE 0900 UTC RUC ANALYSIS
THE UPPER LEVEL LOW COULD BRUSH BY THIS AREA DROPPING SNOW LEVELS
TO 3000 FEET AND LOCALLY TO 2500 FEET DURING PERIODS WHEN
PRECIPITATION WOULD BE FALLING. THIS WILL RESULT IN SNOW
ACCUMULATIONS OF 3 TO 5 INCHES OVER THE NEXT 12 HOURS PROMPTING A
WINTER WEATHER ADVISORY FOR ELEVATIONS GREATER THAN 3000 FEET IN
THIS AREA.
ONCE THIS LOW PASSES SOUTH A RIDGE OF HIGH PRESSURE WILL BUILD OVER
THE EASTERN PACIFIC LEAVING THE AREA DRY THROUGH THURSDAY MORNING.
CURRENT MODEL SOLUTIONS SLIDE A WEAK SHORT WAVE ACROSS THE NORTHBAY
AREA THURSDAY RESULTING IN INCREASED CLOUDS AND A CHANCE OF RAIN
WHICH IS EXPECTED TO SLIDE SOUTH FRIDAY MORNING.
AFTER FRIDAY...A RIDGE DEVELOPS OVER CALIFORNIA KEEPING THE STORM
TRACK JUST NORTH OF THE REGION. AT THIS POINT WILL NOT MENTION RAIN
IN THE FORECAST FOR THE WEEKEND...BUT WILL REINTRODUCE THE
SLIM POSSIBILITY OF RAIN SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 10:40 PM MONDAY...MVFR CONDITIONS TONIGHT WITH
LIGHT SHOWER ACTIVITY INCREASING TUESDAY MORNING. A COLD UPPER LOW
WILL SLIDE SOUTH ALONG THE CALIFORNIA COAST TUESDAY. THE INSTABILITY
IN THE VICINITY OF THE LOW MAY INITIATE A FEW THUNDERSTORMS AS WELL.
VICINITY OF KSFO...MVFR THROUGH TONIGHT. LIGHT SHOWERS TUESDAY
MORNING WITH VFR THROUGH TUESDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...MVFR/VFR TONIGHT AND TUESDAY WITH INCREASING
COVERAGE OF SHOWERS VERY LATE TONIGHT AND TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...WINTER WEATHER ADVISORY ABOVE 3000 FEET FOR
SANTA LUCIA MTNS AND LOS PADRES NATIONAL FOREST
STARTING 6AM THIS MORNING.
.SCA...FOR ALL COASTAL WATERS AND MONTEREY BAY
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: GUDGEL/W PI/CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KEKA 091141
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
341 AM PST TUE FEB 9 2010
.SYNOPSIS...SHOWERS WILL COME TO AN END THIS MORNING AS HIGH
PRESSURE BUILDS OVER THE REGION. MORE PRECIPITATION IS EXPECTED
THURSDAY INTO FRIDAY AS ANOTHER FRONT PUSHES ASHORE.
&&
.DISCUSSION...WATER VAPOR IMAGERY CLEARLY SHOWS LOW PRESSURE JUST
OFF THE CALIFORNIA COAST. RADAR SHOWS SCATTERED SHOWERS MOSTLY
SOUTH OF CAPE MENDOCINO AT THIS TIME. THIS IS A LITTLE FURTHER TO
THE WEST THAN EXPECTED. HOWEVER, THE BENEFITS ARE LESS
PRECIPITATION AND SNOW LEVELS ABOUT 1000 FT HIGHER SINCE THE LARGE
AREA OF COLD AIR IS MOSTLY OFFSHORE. THUNDERSTORM ACTIVITY IS
MINIMAL, BUT LEFT MENTION OF IT IN THE SOUTHERN WATERS FORECAST
FOR THE MORNING HOURS SINCE MODELS STILL SHOW SOME INSTABILITY.
THE LOW AND ITS PRECIPITATION WILL CONTINUE TO MOVE TO THE SOUTH
TODAY. SHOWERS WILL DIMINISH BY THE AFTERNOON AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS OVER THE AREA. DRY WEATHER IS EXPECTED
TONIGHT THROUGH WEDNESDAY NIGHT. MORE RAIN WILL THREATEN THE AREA
IN ADVANCE OF THE NEXT FRONT. THE MAIN THREAT OF PRECIPITATION
WILL BEGIN LATE WEDNESDAY NIGHT. THE HIGHEST POPS WILL BE NEAR THE
CA/OR BORDER AND GRADUALLY DECLINE FURTHER SOUTH. HOWEVER, RAIN
WILL OVERSPREAD THE ENTIRE AREA THURSDAY INTO FRIDAY AS THE FRONT
MOVES ONSHORE. STROZ
&&
.AVIATION...AN APPROACHING TROUGH ALOFT WILL CONTINUE TO GENERATE
WEAK INSTABILITY AND SCATTERED SHOWERS THROUGH 11 AM PST. SHOWER
ACTIVITY WILL DIMINISH THIS AFTERNOON AND EVENING AS THE LOW MOVES
SOUTHWARD AWAY FROM THE AREA. LOW CEILINGS AND ISOLATED VSBY
RESTRICTIONS IN BR AND SHRA SHOULD IMPROVE THIS AFTERNOON. DJB
&&
.MARINE...HIGH PRES OVER THE E PAC WILL CONTINUE TO PRODUCE LIGHT
TO MODERATE NORTHERLY WINDS THROUGH TONIGHT. A WEAK LOW WILL
APPROACH ON WED AND BRING A THREAT OF GALE FORCE WINDS ON THU.
LARGE WESTERLY SWELL GENERATED FROM THIS STORM WILL BUILD ON FRI
AND REMAIN HIGH THROUGH SAT. DJB
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KLOX 091136
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
330 AM PST TUE FEB 9 2010
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TODAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOL TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK.
&&
.SHORT TERM (TODAY-THU)...
A COLD WOBBLY LOW JUST WEST OF THE BAY AREA WILL MOVES SOUTHWARD
TODAY. IT WILL BRING SHOWERS TO THE AREA TODAY...OVERNIGHT AND INTO
WEDNESDAY MORNING BEFORE EXITING THE REGION. THIS KIND OF SYSTEM IS
VERY TRICKY TO FORECAST AS ONLY SLIGHT VARIATION IN THE STORM TRACK
PRODUCE LARGE CHANGES IN THE AMOUNT OF RAINFALL. THE MDLS ARE ALSO
HAVING SOME PROBLEMS WITH THE EXACT TRACK WITH LAST NIGHTS MDLS
INLAND...YDYS RUNS SHOWING A LITTLE MORE OFFSHORE...LAST EVENINGS
RUNS WERE VERY WET WITH A GOOD OFFSHORE TRACK...AND NOW THE LATEST
RUNS ARE SHOWING A DRIER MORE INLAND PATH. THESE DIFFERENCES WILL
NOT AFFECT WEATHER OR NOT IT WILL RAIN OR NOT...JUST THE AMOUNT OF
RAIN. THE MOST INTERESTING ASPECT OF TODAYS SYSTEM IS HOW THE COLD
AIR ALOFT AND THE DIFFLUENT JET DYNAMICS WILL CONSPIRE TO PRODUCE
BOTH THERMODYNAMIC AND DYNAMIC CONVECTIVE INSTABILITY. THERE HAVE
ALREADY BEEN LIGHTNING STRIKES OFFSHORE IN THE COLD CORE OF THE LOW
AND A SLIGHT CHANCE OF TSTMS WILL OCCUR THIS AFTERNOON AND
OVERNIGHT. THE BEST CHANCE OF THE TSTMS WILL OCCUR WHEN THE CORE OR
LOW IS CLOSEST TO ANY GIVEN AREA.
THE SYSTEM SEEMS TO MOVING A LITTLE FASTER THAN CURRENT MDLS
ADVERTISE WITH SOME SHOWERS JUST NOW APPROACHING THE NORTHWEST TIP
OF SLO COUNTY. LOOK FOR RAIN AND A SLIGHT CHC OF TSTMS TO DEVELOP
OVER THE CENTRAL COAST THIS MORNING AND THEN THE SHOWERS AND SLGT
CHC OF TSTMS WILL SPREAD INTO VTA AND LA COUNTIES THIS AFTERNOON.
RAIN WILL TAPER OFF OVER THE CENTRAL COAST LATER THIS EVENING AND
END OVERNIGHT WHILE SOUTH OF POINT CONCEPTION THE SHOWERS WILL TAPER
OFF AFTER MIDNIGHT AND END WEDNESDAY MORNING.
THIS WILL BE A COLD SYSTEM WILL LOW SNOW LEVELS...BUT SINCE IT LOOKS
LIKE THE LOW WILL TAKE A SLIGHT OFFSHORE TRACK THE SNOW LEVELS WILL
NOT BE AS LOW AS THEY WERE FCST EARLIER WHEN THE MDLS HAD MORE OF A
OVERLAND TRACK. SNOW LEVELS WILL BE BETWEEN 4500 AND 5000 FEET THIS
MORNING...THEN WILL LOWER TO BETWEEN 3000 AND 4000 FEET TONIGHT. AS
MUCH AS A FOOT OF SNOW MAY FALL IN THE MOUNTAINS OF VENTURA AND LOS
ANGELES COUNTIES LATER TODAY AND TONIGHT.
OVERALL...RAINFALL TOTALS ARE NOT EXPECTED TO BE EXCEPTIONALLY
HEAVY...AND WILL BE HIGHLY VARIABLE DUE TO THE SHOWERY NATURE OF THE
PRECIPITATION. HOWEVER...EXPECT RAINFALL TOTALS TO AVERAGE ONE THIRD
OF AN INCH TO ONE INCH ACROSS THE AREA...ALTHOUGH LOCAL TOTALS OVER
2 INCHES ARE POSSIBLE IN AREAS THAT RECEIVE THUNDERSTORMS.
PEAK RAINFALL RATES OF ONE HALF TO THREE QUARTERS OF AN INCH PER
HOUR ARE POSSIBLE IN HEAVIER SHOWERS AND THUNDERSTORMS. THE MOST
LIKELY TIME PERIOD FOR THE HEAVY SHOWERS ACROSS SAN LUIS OBISPO AND
SANTA BARBARA COUNTIES WILL BE THIS MORNING THROUGH THIS
AFTERNOON...AND ACROSS VENTURA AND LOS ANGELES COUNTIES THIS
AFTERNOON THROUGH LATE THIS EVENING.
SNOW ACCUMULATIONS FOR THE L.A. AND VTA MTNS WILL GENERALLY BE
BETWEEN 6 AND 12 INCHES. LOCAL AMOUNTS UP TO 16 INCHES WILL BE
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. THE SLO
AND SBA MTNS WILL LIKELY SEE BETWEEN 3 AND 6 INCHES OF NEW SNOW. THE
LOW SNOW LEVELS WILL ALSO ALLOW FOR AN INCH OR TWO OF SNOW IN
FOOTHILLS OF THE ANTELOPE...CUYAMA...AND SLO INTERIOR VLYS.
THE STORM WILL EXIT THE AREA WEDNESDAY AND NOW LOOKS LIKE IT WILL
EXIT ALONG A MORE SOUTHWESTERLY PATH WHICH WILL ELIMINATE THE WRAP
AROUND FLOW INTO THE NORTH SLOPES OF MTNS. SKIES WILL CLEAR IN THE
WAKE OF THE STORM BUT WITH 556DM HGTS OVERHEAD WEDNESDAY MAX TEMPS
IN THE COASTS AND VLYS WILL STRUGGLE TO REACH THE LOWER 60S.
THURSDAY WILL BE UNEVENTFUL WITH A RIDGE IN PLACE. THE ONLY QUESTION
IS WEATHER TO CALL THE SLO/SBA SKIES MOSTLY SUNNY OR PARTLY CLOUDY
AS SOME MOISTURE WORKS ITS WAY THROUGH THE TOP OF THE RIDGE. HGTS
WILL BE UP A FEW DECAMETERS AND MAX TEMPS WILL WARM A FEW DEGREES
FROM WEDNESDAYS CHILLY READINGS.
.LONG TERM (FRI-MON)...
GFS AND EC IN DECENT AGREEMENT FOR THE EXTENDED PERIOD. BOTH NOW
SHOW NO HOPE OF RAIN FROM THE DYING FRONT ON FRIDAY. THE ONLY THAT
HAPPENS IS THE HGTS GET KNOCKED DOWN SOME AND MAX TEMPS WILL BE
SIMILAR TO THURSDAYS.
A RIDGES BULGES INTO THE AREA OVER THE WEEKEND WITH ENOUGH OFFSHORE
FLOW TO CREATE A NICE BUMP UP IN TEMPS AND MAX TEMPS IN THE LOWER
70S ACROSS THE L.A. CSTS. THE RIDGE DOES NOT MOVE MUCH AND AT THIS
TIME IT LOOKS LIKE NEXT MONDAY WILL SIMILAR TO SUNDAY.
&&
.AVIATION...
09/1125Z
COLD UPPER LOW WILL DROP SOUTH ACROSS THE AREA TODAY...BRINGING AN
UNSTABLE AIR MASS ALONG WITH MVFR (AND POTENTIALLY ISOLATED IFR)
CONDS TO THE AREA. GIVEN THE INSTABILITY ASSOCIATED WITH THE STORM
WILL INTRODUCE VCTS REMARKS FOR ALL TAF SITES WITH THE 12Z PACKAGE.
BEST CHANCES FOR SHRA/TS WILL BE THIS MORNING/EARLY AFTERNOON NORTH
OF POINT CONCEPTION...AND THIS AFTERNOON/EVENING SOUTH OF POINT
CONCEPTION. ANY TSTMS THAT FORM WILL BE CAPABLE OF GUSTY WINDS...
BRIEF HEAVY SHOWERS AND HAIL.
KLAX...LOW TO MODERATE CONFIDENCE IN 12Z TAF. TIMING OF SHOWERS AND
POSSIBLE THUNDERSTORMS COULD BE AN HOUR OR TWO EARLY THAN FORECAST
IN TAF. AN EAST WINDS 5-8 KNOTS WILL CONTINUE THROUGH THE MORNING
HOURS.
KBUR...LOW TO MODERATE CONFIDENCE IN 12Z TAF. TIMING OF SHOWERS
AND POSSIBLE THUNDERSTORMS COULD BE AN HOUR OR TWO EARLY THAN
FORECAST IN TAF.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING (SEE LAXWSWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
&&
$$
PUBLIC...RORKE
AVIATION...THOMPSON
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 091123 AAA
AFDPSR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
420 AM MST TUE FEB 9 2010
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
EXPECT AN INCREASE IN MAINLY HIGH CLOUDS TODAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW
SHOWERS...AS WELL AS A SLIGHT CHANCE OF A THUNDERSTORM...WILL OCCUR
OVER FAR SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY
TONIGHT INTO EARLY WEDNESDAY...AND MAINLY OVER SOUTHWEST AND SOUTH-
CENTRAL ARIZONA WEDNESDAY. DRIER CONDITIONS WILL PREVAIL THURSDAY AS
THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL.
WARMER WEATHER WILL SLOWLY RETURN HEADING INTO THE WEEKEND WITH
ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
IMPRESSIVE LOW IS QUICKLY DIVING ALONG THE NRN CA COAST THIS
MORNING...PRETTY MUCH AS EXPECTED. SOUTHERN BRANCH OF THE JET IS
ALSO RESPONDING TO THE INCOMING LOW AS CAN BE SEEN WITH THE FLARE-UP
IN PWAT AND IR IMAGERY...AGAIN AS EXPECTED.
00Z MODELS APPEAR TO HAVE A PRETTY GOOD HANDLE ON THE SYSTEM AND
REMAIN IN GENERALLY GOOD AGREEMENT AS IT TRAVERSES OUR CWA THOUGH
THERE REMAIN MINOR IMPORTANT DIFFERENCES. MODELS HAVE TAKEN A
NOTICEABLE SW JOG WITH THE SYSTEM...NOT SURPRISING GIVEN IT IS A BIT
COLDER AND STRONGER THEN EXPECTED. IT NOW APPEARS THE STRONGEST
FORCING WILL IMPACT OUR WRN CWA...THEN SWING SOUTH AND EAST OF OUR
AREA. OVERALL SYSTEM REMAINS VERY IMPRESSIVE WITH IT/S FORCING
FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE IN SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S ON THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
KPHX AND KIWA...
LIGHT WINDS FROM THE EAST THIS MORNING ARE EXPECTED TO BECOME
VARIABLE AFTER 2000 TO 2200 GMT THIS AFTERNOON...THEN FROM THE EAST
AGAIN AFTER ABOUT 0400 GMT AT KIWA AND 0800 GMT AT KPHX TONIGHT.
HIGH CLOUDINESS IS EXPECTED TO INCREASE FROM THE SOUTHWEST BY THIS
AFTERNOON AND TONIGHT WITH A FEW TO SCATTERED CLOUDS NEAR 7 AND 14
THOUSAND FEET.
KIPL AND KBLH...
LIGHT AND VARIABLE WINDS ARE EXPECTED THIS MORNING BECOMING FROM THE
SOUTH AROUND 10 KNOTS LATE THIS MORNING AND/OR THIS AFTERNOON...THEN
FROM THE SOUTHWEST AND WEST TONIGHT. INCREASING AND LOWERING
CLOUDINESS IS EXPECTED THROUGH THE PERIOD WITH CEILINGS LOWERING TO
6 THOUSAND FEET AFTER 0800 GMT TONIGHT AND AS LOW AS 4 THOUSAND FEET
AFTER 1000 GMT WITH VISIBILITY DROPPING TO NEAR 5 MILES IN SHOWERS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY NIGHT THROUGH MONDAY...
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. MINIMUM RELATIVE
HUMIDITY IS EXPECTED TO GENERALLY REMAIN ABOVE 20 PERCENT WITH GOOD
TO EXCELLENT RECOVERY AT NIGHT. SOME BREEZINESS FROM THE NORTH AND
NORTHEAST IS EXPECTED THIS WEEKEND...ESPECIALLY DOWN THE LOWER
COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS65 KREV 091103
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
300 AM PST TUE FEB 9 2010
.SHORT TERM...
BAND OF LIGHT SNOW SHOWERS MOVED THROUGH THE RENO-TAHOE AREA AROUND
MIDNIGHT...PROGRESSING EAST OF THE RENO AREA. DIDN`T SEE MUCH OUT OF
THIS...BUT IT WAS ENOUGH FOR A DUSTING AT THE NWS OFFICE HERE AT
5000 FEET. IR IMAGERY IS SHOWING SOME COOLING CLOUD TOPS OVER
NORTHERN CA/WESTERN NV ASSOCIATED WITH DIFFLUENCE ALOFT FROM THE
UPPER LOW JUST OFF THE CALIFORNIA COAST...WHICH IS PROMISING FOR
SOME INCREASING SHOWERS THIS MORNING. THE LOW IS MOVING QUICKLY DOWN
THE COAST...AND MAY EVEN BE FASTER THAN SOME OF THE MODELS ARE
CURRENTLY SUGGESTING.
THE TRACK OF THE LOW HAS TRENDED FURTHER WEST OVER THE LAST 24
HOURS...WHICH HAS IN TURN PULLED INSTABILITY/FRONTOGENESIS AND
QPF/SNOW FURTHER WEST AS WELL. THIS WAS A POSSIBILITY THAT WE WERE
AWARE THAT COULD HAPPEN...AND NOW IT LOOKS LIKE WE AREN`T GOING TO
SEE MUCH AT ALL. INSTABILITY WILL BE LIMITED...ONLY LOOKING AT
MARGINAL INSTABILITY COMPARED TO WHAT WE WERE EXPECTING THE LAST
COUPLE DAYS. STILL ENOUGH TO SEE SOME NUMEROUS TO SCATTERED SHOWERS
THROUGH THE DAY...BUT DEFINITELY MUCH LESS THAN PREVIOUSLY FORECAST.
MOST OF THE SHOWER ACTIVITY WILL BE SOUTH OF HIGHWAY 50 THIS
AFTERNOON WITH VERY SPOTTY ACCUMULATIONS DUE TO THE CONVECTIVE
NATURE OF THE PRECIP. COULD SEE SOME ENHANCED ACCUMULATIONS IN THE
EASTERN SLOPES OF MONO COUNTY THIS AFTERNOON AND EVENING...WITH SOME
LIGHT EAST/UPSLOPE FLOW ENHANCING THE LIFT. BUT EVEN THAT DOESN`T
LOOK ALL THAT GOOD ANYMORE WITH ONLY 5-10 KTS EAST FLOW AT 700MB.
BOTTOM LINE...SNOW ACCUMULATIONS WILL BE VERY SPOTTY TODAY. SOME
LOCATIONS WILL SEE NO SNOW AT ALL. OTHERS WILL SEE AN INCH OR TWO IF
THEY GET UNDERNEATH ONE OF THE HEAVIER SHOWERS. AS FOR THE RENO
AREA...WE MAY NOT SEE MUCH AT ALL...WITH MOST OF THE SHOWER ACTIVITY
SHIFTING QUICKLY TO THE SOUTH BY AFTERNOON.
SHOULD SEE AN INCREASE IN SHOWER ACTIVITY ALONG THE SIERRA CREST
THROUGH MORNING...BUT THEN QUICKLY SHIFTING THE FOCUS SOUTHWARD THIS
AFTERNOON AS THE LOW PULLS SOUTH OF THE BAY AREA. LOWERED POPS THIS
AFTERNOON NORTH OF HIGHWAY 50...AS SHOWERS BECOME MORE SCATTERED TO
ISOLATED WITH THE DECREASING INSTABILITY. DAY SHIFT MAY NEED TO CUT
THESE COMPLETELY IF IT LOOKS LIKE THE LOW IS MOVING FASTER THAN
FORECAST. ALSO...INCREASED TEMPERATURES FOR TODAY AS THE COLDEST AIR
IS NOW EXPECTED TO REMAIN WELL TO THE WEST OF OUR AREA...BUT SNOW
LEVELS WILL STILL BE AROUND 4000-4500 FEET SO MOST VALLEYS WILL
STILL SEE SNOW SHOWERS EXCEPT FOR AROUND THE LOWEST VALLEYS SUCH AS
THE CARSON SINK WHERE IT WILL BE MIXED SHOWERS.
SHOULD SEE WARMER AND DRIER CONDITIONS BY WEDNESDAY AS A SHORT WAVE
RIDGE MOVES OVERHEAD. NEXT STORM SYSTEM APPROACHES THE CA/OR COAST
BY LATE THURSDAY...WITH INCREASING CLOUD COVER AND CHANCES OF PRECIP
IN THE SIERRA NORTH OF TAHOE. HOON
.LONG TERM (THURSDAY NIGHT THROUGH MONDAY)...
MEAN HGTS FOR PD POINT TO FLAT RDG ACRS THE WRN CONUS WITH PAC
SYSTEMS TO BE DEFLECTED INTO THE PACNW BYND FRI. MODELS HAVE BACKED
OFF A BIT ON THE SYST FRI WITH THE ECMWF MUCH DRIER AND FURTHER NWD.
THE FCST WAS KEPT CLOSER TO THE GFS WHICH MAINTAINED ITS PREV
THINKING ALTHOUGH PERHAPS A BIT SLOWER/FURTHER NORTH AND OPEN WITH
ITS S/W FEATURE. POPS WERE REDUCED MOST AREAS THU NGT AND IN SRN ZNS
FRI TO TREND IN THE DIRECTION OF THE ECMWF. NOT A BIG WEATHER MAKER
NONETHELESS WITH SNOW LVLS ABV LOWER VLY FLOORS AND ONLY BRIEF
IMPACTS TO TRAVEL ACRS THE SIERRA LATE THU NGT-FRI. RDG AND MUCH
WARMER AIRMASS OVR THE WEEKEND INTO EARLY NEXT WEEK WITH WK S/W
ENERGY AND LOW POPS STILL POSSIBLE ACRS THE NRN PART OF THE FCST
AREA. TEMPS NEAR OR SLIGHTLY BELOW NORMAL FRI WL FINALLY RISE THIS
WEEKEND WITH 40S AND 50S MANY AREAS. HOHMANN
&&
.AVIATION...
COLD UNSTABLE SYSTEM DROPPING SWD ALG/JUST OFF W COAST THIS MRNG...
A BIT FURTHER WEST THAN PREV THINKING. THIS WL RESULT IN HEAVIEST
SHOWERS STAYING OVR CA AND WEST OF CREST WITH MORE SCATTERED AND
LIGHTER ACTVTY ACRS WRN NV/SIERRA. BAND OF SNOW OVR WRN NV THIS MRNG
WL CONT TO LIFT NWD AND SLOWLY DIMINISH THRU 15Z WITH LGT ACCUM
MAINLY ABV 5000 FT. AS UPR LOW TRACKS SWD THRU THE DAY EMPHASIS FOR
SHOWERS WL SHIFT TO THE ERN SIERRA OF MONO CO WHERE PDS OF IFR/MTS
OBSCUREMENT WL PREVAIL FOR ABOUT 6 HRS THIS AFTN.
FOR KRNO...PDS OF LGT SNOW WL TAPER EARLY THIS MRNG AND END BY 15Z.
FLIGHT RESTRICTIONS MAINLY MVFR WITH MT OBSCUREMENT. IMPROVING CONDS
15Z-18Z WITH SCT -SHSN/MT TOP OBSCUREMENT AND ONLY OCNL MVFR CONDS
18Z-00Z. NO SNOW ACCUM EXPECTED ON THE RUNWAY.
FOR KTVL/KTRK...SCT-NMRS -SHSN/MT OBSCUREMENT IN LOW CLOUDS TODAY
WITH OCNL IFR CONDS IN BRIEF HEAVIER SHSN. ONLY LGT SNOW ACCUM ON
RUNWAYS. CONDS WL IMPROVE RAPIDLY FROM N-S EARLY TNGT. CLEARING WL
ALLOW FOR PATCHY FZFG AT KTRK AFT 10/08Z WITH 3-5SM BR AT KTVL.
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KHNX 091025
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
225 AM PST TUE FEB 9 2010
.SYNOPSIS...
A PACIFIC STORM WILL MOVE THROUGH THE CENTRAL CALIFORNIA INTERIOR
TODAY THROUGH WEDNESDAY MORNING. THE HEAVIEST PRECIPITATION WILL
BE TONIGHT...WITH MOUNTAIN SNOW DOWN TO THE PASS LEVEL IN KERN
COUNTY. PATCHY FOG TO THE SAN JOAQUIN VALLEY WILL RETURN THURSDAY
MORNING A HIGH PRESSURE BUILDS BACK OVER THE REGION.
&&
.DISCUSSION...
LIGHT PRECIPITATION MOVED INTO THE WESTERN HALF OF THE HANFORD
WARNING/FORECAST AREA MONDAY NIGHT. RAINFALL AMOUNTS SO FAR HAVE
RANGED FROM A TRACE TO ONLY A FEW HUNDREDTHS OF AN INCH.
THE 00Z MODELS ARE KEEPING THE UPPER-LEVEL LOW OFFSHORE AS IT DROPS
SOUTH...THEN TURNS IT EAST INTO NORTHERN BAJA CALIFORNIA. HOWEVER...
THE 06Z NAM-12 TRACKS THE LOW SOUTH ALONG THE COAST...BRINGING COLDER
AIR INTO THE HANFORD WARNING/FORECAST AREA. PER COORDINATION WITH
NEIGHBORING WFO/S...HAVE LOWERED SNOW LEVELS OVER THE KERN COUNTY
MOUNTAINS TO 3500-4000 FEET BY 12Z WEDNESDAY.
THE 00Z GFS HAS THE HEAVIEST PRECIPITATION AT FRAZIER PARK BEGINNING
AFTER 18Z TODAY...AND ENDING BY 12Z WEDNESDAY. THE 06Z NAM HAS LIGHT
PRECIPITATION AT FRAZIER PARK THROUGH 21Z THIS AFTERNOON...THEN A
9-HOUR PERIOD OF HEAVIER PRECIPITATION. MODEL STORM-TOTAL QPF FOR
FRAZIER PARK RANGE FROM 0.57 INCH ON THE NAM TO 0.70 INCH ON THE
GFS. THE BULK OF THE PRECIPITATION SHOULD FALL AS SNOW..BUT BASED ON
MODEL QPF SHOULD NOT SEE MORE THAN 5-7 INCHES OF SNOW ABOVE 4500
FEET. IN THE SOUTHERN SIERRA NEVADA...SNOW ACCUMULATIONS ABOVE 7000
FEET WILL BE UP TO 10 INCHES...MAINLY OVER THE TULARE COUNTY
MOUNTAINS TONIGHT WITH WRAP-AROUND MOISTURE AS THE UPPER-LEVEL LOW
MOVES SOUTH. WILL REPLACE THE WINTER STORM WATCH FOR THE KERN COUNTY
MOUNTAINS WITH A WINTER WEATHER ADVISORY...AND WILL ALSO ISSUE AN
ADVISORY FOR THE TULARE COUNTY MOUNTAINS. NORTH OF KINGS CANYON...
THERE WILL ONLY BE LOCAL ACCUMULATIONS AT ADVISORY LEVELS...SO WILL
COVER WITH A SPECIAL WEATHER STATEMENT.
FOR THE SAN JOAQUIN VALLEY AND THE ADJACENT FOOTHILLS...THE 06Z
NAM-12 HAS SURFACE COMPUTED CAPES UP TO 420 JOULES/KG OVER WESTERN
FRESNO COUNTY AT 21Z...AND ALSO OVER THE GRAPEVINE. SURFACE COMPUTED
LIFTED INDEXES ARE NEGATIVE OVER MOST OF THE HANFORD WARNING/
FORECAST AREA...AND EVEN WITH THE COLDEST 500-MN AIR OFF THE COAST
OF SAN LUIS OBISPO COUNTY...500-MB TEMPERATURES OVER THE HANFORD
FORECAST AREA ARE AROUND -27 C. HOWEVER...THE NAM-12 KEEPS THE
300-MB JET WELL OFFSHORE UNTIL TONIGHT...WHEN IT MOVES OVER THE
CENTRAL CALIFORNIA INTERIOR AFTER 06Z WEDNESDAY.
SPC HAS MOST OF THE REGION UNDER A GENERAL RISK OF THUNDERSTORMS...
SO HAVE PENCILED IN AFTERNOON THUNDERSTORMS OVER THE CENTRAL AND
SOUTHERN SAN JOAQUIN VALLEY... THE SOUTHERN SIERRA NEVADA
FOOTHILLS...AND THE NORTH SLOPES OF THE TEHACHAPI MOUNTAINS. WILL
ISSUE A SPECIAL WEATHER STATEMENT ON THE CONVECTIVE POTENTIAL.
AS THE UPPER-LEVEL TROUGH MOVES INLAND WEDNESDAY...AN EAST-PACIFIC
RIDGE WILL BUILD INTO CALIFORNIA BEHIND IT. WITH A STABLE AIRMASS
ALOFT AND A SUPPLY OF LOW-LEVEL MOISTURE...CONDITIONS WILL BE RIGHT
FOR PATCHY FOG DEVELOPMENT OVER THE CENTRAL AND SOUTHERN SAN JOAQUIN
VALLEY WEDNESDAY NIGHT/THURSDAY MORNING.
THE NAM-12 BRINGS A WEAK UPPER-LEVEL TROUGH INTO CALIFORNIA FRIDAY.
THE 12Z UKMET SUPPORTS THIS SOLUTION...BUT THE 00Z ECMWF AND 06Z GFS
HAVE A NEARLY-ZONAL FLOW OVER THE STATE. HAVE KEPT THE CHANCE POPS
OVER THE NORTHERN HALF OF THE HANFORD WARNING/FORECAST AREA FOR
THURSDAY NIGHT AND FRIDAY...BUT CONFIDENCE IS LOWER IN THIS SOLUTION.
BEYOND FRIDAY...THE MEDIUM-RANGE MODELS HAVE RIDGING OVER THE EAST
PACIFIC AND CALIFORNIA THROUGH THE REMAINDER OF THE FORECAST PERIOD.
EXPECT DRY WEATHER TO PREVAIL OVER THE WEEKEND INTO THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...AREAS MVFR IN -RA/BR. IN THE SIERRA
NEVADA AND TEHACHAPI MOUNTAINS...MVFR AND LCL IFR CIGS AND MOUNTAIN
OBSCURATIONS WITH RA/SN SPREADING IN FROM THE NORTHWEST. IN THE
KERN COUNTY DESERT...VFR THROUGH 18Z TUESDAY THEN LCL MVFR IN RA
POSSIBLY MIXED WITH -SN AFTER 04Z WEDNESDAY.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 10 AM PST
WEDNESDAY FOR THE KERN AND TULARE COUNTY MOUNTAINS /CAZ095-097/.
&&
$$
PUBLIC...SANGER
AVN/FW...DCH
SYNOPSIS...SANGER
WEATHER.GOV/HANFORD
000
FXUS65 KPSR 090946
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
245 AM MST TUE FEB 9 2010
.SYNOPSIS...
EXPECT AN INCREASE IN MAINLY HIGH CLOUDS TODAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW
SHOWERS...AS WELL AS A SLIGHT CHANCE FOR A THUNDERSTORM...WILL OCCUR
OVER FAR SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY
TONIGHT INTO EARLY TOMORROW...AND MAINLY OVER SOUTHWEST AND
SOUTH-CENTRAL ARIZONA TOMORROW. DRIER CONDITIONS WILL PREVAIL
THURSDAY AS THE LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN
RATHER COOL. WARMER WEATHER WILL SLOWLY RETURN HEADING INTO THE
WEEKEND WITH ABOVE NORMAL TEMPERATURES LIKELY BY SATURDAY.
&&
.DISCUSSION...
IMPRESSIVE LOW IS QUICKLY DIVING ALONG THE NRN CA COAST THIS
MORNING...PRETTY MUCH AS EXPECTED. SOUTHERN BRANCH OF THE JET IS
ALSO RESPONDING TO THE INCOMING LOW AS CAN BE SEEN WITH THE FLARE-UP
IN PWAT AND IR IMAGERY...AGAIN AS EXPECTED.
00Z MODELS APPEAR TO HAVE A PRETTY GOOD HANDLE ON THE SYSTEM AND
REMAIN IN GENERALLY GOOD AGREEMENT AS IT TRAVERSES OUR CWA THOUGH
THERE REMAIN MINOR IMPORTANT DIFFERENCES. MODELS HAVE TAKEN A
NOTICEABLE SW JOG WITH THE SYSTEM...NOT SURPRISING GIVEN IT IS A BIT
COLDER AND STRONGER THEN EXPECTED. IT NOW APPEARS THE STRONGEST
FORCING WILL IMPACT OUR WRN CWA...THEN SWING SOUTH AND EAST OF OUR
AREA. OVERALL SYSTEM REMAINS VERY IMPRESSIVE WITH IT/S FORCING
FIELDS.
MOISTURE REMAINS THE BIG MISSING INGREDIENT AND BASED ON LATEST
SATELLITE DATA I DON/T THINK WE/LL GET ANY SIGNIFICANT MOISTURE
INFLUX. SO THE SYSTEM WILL HAVE TO WORK WITH WHAT IT HAS...RESULTING
IN QPF OF ROUGHLY 1/10 TO 1/4 INCH MOST AREAS. SNOW LEVELS WILL FALL
TO AROUND 4000 FEET ACROSS SE CA. FORECAST SNOW AMOUNTS ARE FOR 2-4
INCHES IN THE JOSHUA TREE NATIONAL PARK TUESDAY EVENING THROUGH
WEDNESDAY MORNING. I/LL BE CONVERTING THE WINTER STORM WATCH TO A
WINTER WEATHER ADVISORY BASED ON THE FORECAST.
STRONGEST FORCING...WHICH WILL BE WANING...SHIFTS INTO SE AZ AND
SONORA DURING THE DAY WEDNESDAY. I ADJUSTED THE POPS DOWN A BIT
BASED ON THE MORE SOUTHERLY TRACK AND THE STILL MISSING MOISTURE.
SOME MINOR SNOW ACCUMULATION WILL BE POSSIBLE FOR SRN GILA COUNTY
PRIMARILY ABOVE 5000 FEET /2-4 INCHES/. TEMPERATURES WILL BE NEARLY
10 DEG BELOW 30 YEAR NORMALS WEDNESDAY.
STRONG RIDGING DEVELOPS BEHIND THE LOW THURSDAY WHICH WILL QUICKLY
BRING THE THREAT OF PRECIP TO AN END. MODELS IN GOOD AGREEMENT THAT
A BROAD H5 RIDGE WILL BUILD OVER THE ERN PAC AND EXTEND INTO THE SW
STATES. FINE WARMING TREND WILL DEVELOP THROUGH THE WEEKEND WITH
SOME GUIDANCE OFFERING HIGHS IN THE 80S FOR THE LOWER DESERTS BY
EARLY NEXT WEEK. WILL HOLD OFF ON THAT MUCH OPTIMISM AT THIS TIME
BUT MID 70S LOOK LIKE A GOOD BET.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX AND KIWA...
THROUGH 18Z TUE...SCT CLDS BASED NEAR 9-11 THSD MSL. LIGHT WIND.
BETWEEN 18Z TUE AND 06Z WED...INCREASING AND LOWERING CLOUDS. CLDS
BECOME BKN TO OVC NEAR 16 THSD MSL BY 22Z TUE. LIGHT WIND.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
THROUGH 12Z TUE...CLEAR SKIES. LIGHT WIND. BETWEEN 12Z TUE AND
06Z WED...INCREASING AND LOWERING CLOUDS. CLDS BECOME BKN TO OVC
NEAR 16 THSD MSL BY 18Z TUE. LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
WEDNESDAY CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...ELLIS
000
FXUS66 KMTR 090640
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1040 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 8:30 PM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
A FEW BANDS OF LIGHT SHOWERS HAVE MOVED ACROSS THE SAN FRANCISCO AND
MONTEREY BAY AREAS THIS EVENING WITH RAINFALL AMOUNTS LESS THAN 0.20
INCH. THESE SHOWERS ARE AHEAD OF THE MAIN SYSTEM WHICH IS DEEPENING
OFF THE NORTHERN CALIFORNIA COAST AT THIS TIME AS IT MOVES SOUTH-
SOUTHEASTWARD. COLD AIR WITH THIS SYSTEM WILL LOWER SNOW LEVELS TO
AROUND 2500 FEET WITH 2-3 INCHES OF SNOW POSSIBLE BELOW 3000 FEET ON
TUESDAY. ABOVE 3000 FEET UP TO 7 INCHES ARE POSSIBLE. THEREFORE...A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR ELEVATIONS ABOVE 2500
FEET FOR TUESDAY BETWEEN 6 AM AND 10 PM. AS THE SYSTEM DEEPENS OVER
THE NEXT 24 HOURS THE COLD AIR ALOFT WILL COMBINE WITH THE DYNAMICS
OF THE SYSTEM TO PRODUCE ISOLATED THUNDERSTORMS...WHICH MAY PRODUCE
BRIEF HEAVY RAIN/SNOW...SMALL HAIL AND GUSTY WINDS. WHEN THE COLD
FRONT MOVES THROUGH THE REGION DURING THE DAY ON TUESDAY WINDS WILL
PICK UP A BIT AND BECOME GUSTY IN THE MOUNTAINS AND HILLS. THE
MOISTURE ASSOCIATED WITH THIS SYSTEM IS LIMITED...ONLY A SMALL AREA
OF 0.88 INCH OF PRECIPITABLE WATER ON THE AMSU WITH THE MAJORITY OF
PW AROUND 0.70 INCH. ERGO...MOST LOCATIONS WILL EXPERIENCE LESS THAN
1/2 INCH WITH UP TO AN INCH POSSIBLE OVER THE HIGHER TERRAIN. ALSO...
THE COLD AIR WILL PLACE AFTERNOON HIGHS 5 TO 10 DEGREES COOLER THEN
CLIMATOLOGICAL NORMALS. AS THE SYSTEM CONTINUES ITS SOUTH-
SOUTHEASTWARD PROGRESSION TUESDAY NIGHT PARTIAL CLEANING IS EXPECTED
ALLOWING THE COLDEST VALLEY LOCATIONS TO DROP BELOW FREEZING WITH
AREAS OF FROST.
WEAK RIDGING FOR WEDNESDAY WILL FOLLOW THE TROUGH BRINGING A WARMER
AND DRY AIRMASS. HOWEVER...IT WILL BE SHORT-LIVED AS THE NEXT SYSTEM
WILL SQUASH THE RIDGE AS ITS HEADS FOR CALIFORNIA. THE MODELS ARE
INDICATING IT IS A FAST MOVER AND WILL JUST BRUSH BY NORTHERN AND
CENTRAL CALIFORNIA THURSDAY INTO FRIDAY IN A TWO WAVE SERIES.
NEITHER WAVE LOOKS IMPRESSIVE FOR US SINCE MOISTURE IS LIMITED AND WE
ARE ON THE SOUTHERN END OF THE WAVES. AT THIS TIME IT LOOKS LIKE
THESE TWO WAVES MAY PRODUCE UP TO AN INCH OF RAIN IN THE HIGHER
TERRAIN AND LESS THAN 1/2 INCH IN THE VALLEY LOCATIONS.
AFTER FRIDAY...A RIDGE DEVELOPS OVER CALIFORNIA KEEPING THE STORM
TRACK JUST NORTH OF THE REGION. AT THIS POINT WILL NOT MENTION RAIN
IN THE FORECAST FOR THE WEEKEND...BUT WILL REINTRODUCE THE
POSSIBILITY OF RAIN SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 10:40 PM MONDAY...MVFR CONDITIONS TONIGHT WITH
LIGHT SHOWER ACTIVITY INCREASING TUESDAY MORNING. A COLD UPPER LOW
WILL SLIDE SOUTH ALONG THE CALIFORNIA COAST TUESDAY. THE INSTABILITY
IN THE VICINITY OF THE LOW MAY INITIATE A FEW THUNDERSTORMS AS WELL.
VICINITY OF KSFO...MVFR THROUGH TONIGHT. LIGHT SHOWERS TUESDAY
MORNING WITH VFR THROUGH TUESDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...MVFR/VFR TONIGHT AND TUESDAY WITH INCREASING
COVERAGE OF SHOWERS VERY LATE TONIGHT AND TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: EVANS
AVIATION/MARINE: GUDGEL/W PI/CANEPA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 090619
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1000 PM PST MON FEB 8 2010
...NEW AVIATION DISCUSSION...
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TUESDAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOL TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK...WITH THE EXCEPTION OF SOME LIGHT SHOWERS
POSSIBLE ON FRIDAY.
&&
.SHORT TERM (TONIGHT-THU)...
VIGOROUS UPPER LOW OFF THE OREGON COAST THIS EVENING WAS BEGINNING
TO DROP SWD PARALLEL TO THE WEST COAST. EARLIER...THE WRF SHOWED A
SLIGHTLY FARTHER W TRACK WITH THIS SYSTEM...KEEPING IT OVER WATER AS
IT PASSES JUST TO THE W OF THE FCST AREA TUESDAY AFTERNOON AND
TUESDAY NIGHT. THE GFS IS ALSO FARTHER W WITH ITS TRACK. THE TRACK
FARTHER OFF THE COAST WILL ALLOW THE SYSTEM TO PICK UP SOME MOISTURE
FROM THE PACIFIC. WHILE PRECIPITABLE WATER VALUE ARE NOT EXCESSIVELY
HIGH DUE TO THE COLD NATURE OF THE STORM...THEY STILL POP UP TO
BETWEEN .75 AND .80 JUST OFF THE COAST TUE. IN ADDITION...THE TRACK
PLACES THE FCST AREA UNDER THE FAVORABLE NE QUADRANT OF THE UPPER
LOW FOR A WHILE TUE AFTERNOON AND EVENING...WITH FAIRLY IMPRESSIVE
UPR LVL DIFFLUENCE OF HEIGHTS ALOFT...A HEALTHY AND FAIRLY DEEP
OMEGA FIELD...AND SOME SLY LOW LVL FLOW...PARTICULARLY ACROSS LOS
ANGELES...VENTURA AND SERN SBA COUNTIES. IN ADDITION...THE WRF SHOWS
LIFTED INDEX VALUES BELOW ZERO ACROSS MUCH OF THE REGION TUE
AFTERNOON AND EVENING. WITH A MORE FAVORABLE TRACK OVER THE
WATER...BETTER SLY LOW LEVEL FLOW...DEEPER MOISTURE AND LIFT...
AND AN INCREASED THREAT OF TSTMS...HAVE GONE AHEAD WITH A FLASH
FLOOD WATCH FOR THE RECENT BURN AREAS OF L.A. AND SBA COUNTIES.
THERE IS THE POTENTIAL THAT RAINFALL RATES COULD REACH ONE HALF
INCH TO ONE INCH PER HOUR...EXCEEDING THRESHOLDS DEEMED BY THE USGS
TO BE SUFFICIENT TO CAUSE FLASH FLOODING AND MUD AND DEBRIS FLOWS IN
AND BELOW THE RECENT BURN AREAS.
THE REMAINDER OF THE DISCUSSION STILL HOLDS TRUE...ALTHOUGH IF THE
TRACK OF THE UPPER LOW IS FARTHER OFF THE COAST...SNOW LEVELS WILL
HAVE TO BE ADJUSTED UPWARD A BIT. THAT WILL BE ASSESSED BY LATER
SHIFTS.
FROM PREVIOUS DISCUSSION...
SHOWERS WILL BECOME LIKELY ACROSS THE CENTRAL COAST EARLY TUESDAY
MORNING...THEN ARE EXPECTED TO BECOME WIDESPREAD ACROSS THE FORECAST
AREA BY TUESDAY AFTERNOON. DURING THIS TIME...MODEL CROSS SECTIONS
SHOW DEEPENING MOISTURE AND INCREASING DYNAMICS ACROSS THE REGION.
THERE IS ALSO RAPID COLD AIR ADVECTION ALOFT...WITH VERY IMPRESSIVE
500 MB TEMPERATURES OF -32 DEGREES AT THE CORE OF THE UPPER LOW
CENTER! THIS COLD CORE LOW PRESSURE CENTER IS EXPECTED TO TRACK
RIGHT OVER THE FORECAST AREA TUESDAY NIGHT. AS THE COLDER AIR
FILTERS INTO THE AREA...LOOK FOR INCREASING INSTABILITY WITH
LIFTED INDEX VALUES OF 0 TO -2. THIS TYPE OF PATTERN CERTAINLY
LOOKS CONDUCIVE TO THUNDERSTORM DEVELOPMENT...WITH LOTS OF SMALL
HAIL REPORTS LIKELY. WITH FAIRLY IMPRESSIVE DYNAMICS AND SUCH COLD
AIR ALOFT...NOT OUT OF THE QUESTION THAT SOME HAIL COULD APPROACH
SEVERE LIMITS. IN ADDITION TO HAIL...ANY THUNDERSTORM THAT DEVELOPS
WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS AND BRIEF HEAVY
DOWNPOURS. DUE TO THE CYCLONIC FLOW ALOFT AND UNSTABLE AIR
MASS...THERE WILL ALSO BE THE POTENTIAL FOR WATERSPOUTS OVER THE
COASTAL WATERS...WHICH HAS BEEN HIGHLIGHTED IN A MARINE WEATHER
STATEMENT.
THE BULK OF THE SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TUESDAY
AFTERNOON INTO TUESDAY EVENING...WITH SHOWERS LIKELY REMAINING ACROSS
LOS ANGELES COUNTY OVERNIGHT TUESDAY NIGHT. BY WEDNESDAY
MORNING...ALL MODELS AGREE ON DROPPING THE CLOSED LOW SOUTH AND EAST
OF FORECAST AREA...WITH WRAP AROUND MOISTURE CONTINUING THE THREAT
OF SHOWERS WELL INTO THE DAY WEDNESDAY ACROSS THE MOUNTAINS OF
LA/VTU COUNTIES AS WELL AS THE ANTELOPE VALLEY.
RAINFALL AMOUNTS ARE GENERALLY EXPECTED TO RANGE BETWEEN .50 AND 1.00
INCHES ACROSS COASTAL AND VALLEY AREAS...WITH UP TO 1.50 INCHES
POSSIBLE IN THE FOOTHILLS AND LOWER COASTAL SLOPES. DUE TO THE
SHOWERY NATURE OF THE PRECIPITATION...RAINFALL AMOUNTS ARE EXPECTED
TO BE QUITE VARIABLE. IT IS ALSO IMPORTANT TO REMEMBER THAT HIGHER
RAINFALL AMOUNTS CAN BE EXPECTED FOR THOSE AREAS UNDER
THUNDERSTORMS. AT THIS TIME...IT APPEARS THAT LOS ANGELES COUNTY
WILL LIKELY RECEIVE THE HIGHEST RAINFALL AMOUNTS...ESPECIALLY ACROSS
EASTERN SECTIONS...DUE TO THE BEST CYCLONIC FLOW PATTERN FOR THAT
AREA. THERE WILL BE THE POTENTIAL FOR HEAVIER SHOWERS AND
THUNDERSTORMS ACROSS THE RECENT BURN AREAS...ESPECIALLY LOS ANGELES
COUNTY. FOR THE STATION FIRE...THE BEST CHANCE FOR THE HEAVIER
SHOWERS IS EXPECTED TO OCCUR FROM MID AFTERNOON THROUGH EVENING ON
TUESDAY. RAINFALL RATES ARE GENERALLY EXPECTED TO BE LESS THAN .25
INCHES PER HOUR...BUT WE COULD SEE RATES LOCALLY AS HIGH AS .50
INCHES PER HOUR NEAR HEAVIER SHOWERS OR THUNDERSTORMS. LATER SHIFTS
MAY NEED TO ISSUE A FLASH FLOOD WATCH FOR THE RECENT BURN AREAS OF
LOS ANGELES COUNTY...ESPECIALLY IF THIS SYSTEM TAKES ON A MORE
OVER-WATER TRAJECTORY.
A MAJOR IMPACT OF THIS UPCOMING STORM WILL BE THE VERY LOW SNOW
LEVELS. INITIALLY...SNOW LEVELS ARE EXPECTED TO RANGE BETWEEN 3500
AND 4000 FEET TUESDAY...THEN LOWER QUICKLY TO AROUND 3000 FEET
ACROSS THE NORTHERN MOUNTAINS ON TUESDAY AFTERNOON AS THE COLDER AIR
SPILLS INTO THE REGION. THICKNESS VALUES BOTTOM OUT AT A VERY
IMPRESSIVE 530 DM OVERNIGHT ON TUESDAY NIGHT! AS A RESULT...LOOK FOR
SNOW LEVELS TO FALL TO BETWEEN 2000 AND 2500 FEET TUESDAY
NIGHT...POSSIBLY EVEN LOWER UNDER ANY THUNDERSTORMS. WRAP AROUND
MOISTURE WILL LIKELY BRING THE THREAT OF ADDITIONAL SHOWERS TO THE
MOUNTAINS (ESPECIALLY NORTH FACING SLOPES) AND ANTELOPE VALLEY
THROUGH MUCH OF THE DAY WEDNESDAY. WINTER STORM WATCHES WILL BE
POSTED FOR THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS...WHERE 6 TO
12 INCHES OF SNOW IS EXPECTED...WITH LOCAL AMOUNTS UP TO 16 INCHES
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. DUE TO
THE LOW SNOW LEVELS EXPECTED...MAJOR LOW ELEVATION TRAFFIC CORRIDORS
WILL LIKELY BE IMPACTED BY ACCUMULATING SNOW...INCLUDING INTERSTATE
5 NORTH OF CASTAIC AS WELL AS HIGHWAY 14 THROUGH THE SOLEDAD CANYON.
WINTER WEATHER ADVISORIES HAVE ALSO BEEN POSTED FOR THE MOUNTAINS OF
SLO/SBA COUNTIES...WHERE 3 TO 6 INCHES OF SNOW CAN BE EXPECTED.
THE UNUSUAL LOW SNOW LEVELS WILL LIKELY BRING ACCUMULATING SNOW TO
SUCH PLACES AS THE ANTELOPE VALLEY...CUYAMA VALLEY...INTERIOR VALLEYS
OF SLO COUNTY...AS WELL AS THE HIGHER PEAKS OF THE SANTA MONICA
MOUNTAINS. THESE AREAS MAY REQUIRE WINTER WEATHER ADVISORIES AS WE
DRAW CLOSER TO THE EVENT...FOR NOW JUST HIGHLIGHTED IN A SPECIAL
WEATHER STATEMENT. THIS SYSTEM HAS THE POTENTIAL TO BRING BRIEF SNOW
SHOWERS TO UNUSUAL LOCATIONS ACROSS THE SOUTHLAND TUESDAY
NIGHT...SUCH AS SOME OF THE FOOTHILL LOCATIONS IN LOS ANGELES AND
VENTURA COUNTIES. THE ATMOSPHERE WILL DRY OUT AND BEGIN TO MODIFY
ON THURSDAY.
.LONG TERM (FRI-MON)...
ANOTHER WEAK SYSTEM WILL BRING A CHANCE OF SHOWERS ON FRIDAY...MAINLY
NORTH OF POINT CONCEPTION. HOWEVER...MODELS HAVE BEEN CONTINUING TO
TREND DRIER WITH THIS SYSTEM WITH TIME. THEN DRY WEATHER IS EXPECTED
THROUGH THE REMAINDER OF THE WEEKEND WITH NEAR SEASONAL NORMALS
EXPECTED.
&&
.AVIATION...
09/0615Z.
MID AND HIGH LEVEL CLOUDS WILL OVERSPREAD THE AREA TONIGHT. EVERY
COASTAL TAF HAS A 20 PERCENT OF BRIEF MVFR CIGS. CLOUDS WILL LOWER
WITH THE APPROACH OF THE STORM TUESDAY. WIDESPREAD MVFR CIGS WITH
LOCAL IFR CIGS WILL OCCUR WITH THE ONSET OF THE RAIN DURING THE
AFTERNOON.
KLAX AND KBUR...FAIRLY GOOD CONFIDENCE IN TAFS THROUGH NOON. A 20
PERCENT CHANCE OF A BRIEF MVFR CIG THROUGH 14Z. CIGS AND VIS WILL
LIKELY VARY FREQUENTLY AFTER 23Z TUESDAY.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...ASR
SYNOPSIS...MEIER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSTO 090502
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 PM PST MON FEB 8 2010
.DISCUSSION...
WEAK SHORTWAVE TROUGH NOW MOVING WEST TO EAST THROUGH NORCAL
CARRYING JUST A BIT MORE PUNCH THAT EXPECTED WITH RED BLUFF EVEN
REPORTING A THUNDERSTORM IN THE LAST HOUR. PRECIP AMOUNTS WITH THIS
SYSTEM HOWEVER HAVE BEEN RATHER MINIMAL AND MAX OUT AT AROUND ONE
TENTH OF AN INCH UNDER THE HEAVIEST SHOWERS. CLOUD COVER FROM THIS
SHORTWAVE AND CLOSED LOW OFF THE COAST WILL KEEP VALLEY OVERNIGHT
TEMPERATURES A BIT WARMER THAN THIS MORNINGS. MEANWHILE...OVER THE
HIGHER ELEVATIONS...COLDER AIRMASS BROUGHT IN BY LOW WILL BRING
SLIGHTLY COOLER TEMPERATURES THAN THIS MORNINGS. CLOSED UPPER LOW
STILL FORECAST TO DROP SOUTHWARD OFF THE COAST TONIGHT AND TUESDAY
WITH 00Z NAM TAKING A SLIGHTLY MORE OFFSHORE TRACK THAN THIS
MORNINGS 12Z RUN. THE RESULT OF THIS MORE OFFSHORE TRACK WILL BE
ANOTHER SLIGHT REDUCTION IN ESTIMATED PRECIP AMOUNTS AND SLIGHTLY
HIGHER SNOW LEVELS. THEREFORE...ALTHOUGH SNOW LEVELS WILL BE ON THE
LOW SIDE...STILL EXPECTING ONLY MINIMAL IMPACTS TO MOUNTAIN TRAVEL
WITH ONLY LIGHT SNOWFALL. MAIN INSTABILITY WITH THE LOW LOOKS LIKE
WILL NOW REMAIN OFFSHORE SO BELIEVE THUNDERSTORM THREAT OVER INLAND
NORTHERN CALIFORNIA WILL BE MINIMAL. SLIGHTLY COOLER AIRMASS WILL
MEAN SLIGHTLY COOLER TEMPERATURES OVERALL TUESDAY.
UPPER LOW SHIFTS SOUTH OF CWA BY TUESDAY EVENING AND SHOULD SEE END
OF PRECIP THREAT EXCEPT OVER FAR SOUTHERN CWA. COULD SEE ENOUGH
CLEARING OVER THE CENTRAL VALLEY TUESDAY NIGHT TO ALLOW FOR SOME FOG
FORMATION BUT STILL MAY BE ENOUGH INSTABILITY TO PRECLUDE MUCH AND
SURFACE MOISTURE PROGS NOT REALLY INDICATING SIGNIFICANT FOG
FORMATION AT THIS TIME.
UPPER RIDGING OVER AREA WILL BRING CLEARING SKIES AND WARMER
TEMPERATURES WEDNESDAY WITH ANY PRECIP THREAT STAYING NORTH OF THE
CWA. WEAK SHORTWAVE RIDING OVER THE RIDGE FORECAST TO BRING SLIGHT
PRECIP THREAT TO THE NORTHERN MOUNTAINS WEDNESDAY NIGHT. CLEARER
SKIES FARTHER SOUTH WILL BRING FOG THREAT TO THE SAN JOAQUIN AND
SOUTHERN SACRAMENTO VALLEYS. UPPER RIDGE AXIS FORECAST TO SHIFT
EASTWARD ON THURSDAY ALLOWING NEXT SHORTWAVE TO RIDE OVER RIDGE TO
BRING PRECIP A LITTLE FARTHER SOUTHWARD DURING THE DAY ON THURSDAY.
EVENING NAM NOW BRINGING SLIGHT CHANCE OF PRECIP AS FAR SOUTH AS THE
SACRAMENTO AND STOCKTON AREAS.
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
UPPER RIDGE CONTINUES TO SHIFT EASTWARD ON FRIDAY ALLOWING STRONGER
PACIFIC FRONTAL SYSTEM TO MOVE INLAND. MOISTURE PLUME ASSOCIATED
WITH THIS SYSTEM PREDICTED BY 00Z GFS TO ME MODERATE WITH TPWS
FEEDING INTO IT ABOUT .8 TO .9 INCHES. THIS SYSTEM WILL LOOSE ENERGY
AS IT RUNS UP AGAINST THE RIDGE BUT SHOULD STILL BE A MODERATE
PRECIP PRODUCER.
WEAK RIDGING BUILDS IN OVER NORTHERN CALIFORNIA BEHIND THIS FRONTAL
SYSTEM ON FRIDAY NIGHT AND FORECAST TO BRING DIMINISHING SHOWER
THREAT. UPPER LEVEL RIDGING OVER THE SOUTHWEST U.S. ON SATURDAY AND
SUNDAY SHOULD BRING A BREAK IN PRECIPITATION AND POSSIBLY THE RETURN
OF FOG AND LOW CLOUDS TO THE VALLEYS. ASSUMING CLEARING OF LOW
CLOUDS AND FOG...DAYTIME TEMPERATURES OVER THE WEEKEND SHOULD COME
IN AROUND NORMAL FOR THIS TIME OF YEAR. WEAK SYSTEM PASSING THROUGH
PACIFIC NORTHWEST ON SUNDAY NIGHT MAY BRING SLIGHT THREAT OF PRECIP
OVER THE NORTHERN MOUNTAINS ON SUNDAY NIGHT AND EARLY MONDAY. BOTH
GFS AND ECMWF HAVE RIDGING OVER AREA DURING THIS TIME PERIOD SO
CURRENT POP FORECASTS MAY BE A BIT OVERDONE. FLAT RIDGING REMAINS
OVER AREA ON MONDAY FOR CONTINUED DRY CONDITIONS OF ALL BUT FAR
NORTHERN CWA.
&&
.AVIATION...WEAK SYSTEM IS MOVING ACROSS NORTHERN CALIFORNIA THIS
EVENING...AND WILL BE FOLLOWED BY A SECONDARY SYSTEM DIGGING DOWN
THE COAST TONIGHT AND TUESDAY. AS A RESULT...A FEW LIGHT SHOWERS
ARE PUSHING ACROSS THE VALLEY THIS EVENING...WITH AREAS OF MVFR
CONDITIONS IN THE VALLEY AND IFR/LIFR CONDITIONS IN THE FOOTHILLS
AND SIERRA. MORE WIDESPREAD SHOWERS WILL DEVELOP BETWEEN AFTER 12Z
AS THE SECONDARY SYSTEM DIGS SOUTH. CEILINGS WILL ALSO LOWER...WITH
WIDESPREAD MVFR AND AREAS OF IFR CONDITIONS POSSIBLE IN THE VALLEY
AND IFR/LIFR IN THE SURROUNDING MOUNTAINS AND FOOTHILLS. SNOW
LEVELS WILL ALSO LOWER TO BETWEEN 3500 AND 4000 FEET BY MORNING.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 090502
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
902 PM PST MON FEB 8 2010
.SYNOPSIS...
LOW CLOUDS AND FOG WILL PERSIST FOR MUCH OF TODAY AND TONIGHT
THROUGH THE SAN JOAQUIN VALLEY. THE NEXT FRONTAL SYSTEM WILL MOVE
THROUGH THE REGION TUESDAY NIGHT THROUGH WEDNESDAY PRODUCING RAIN
AND HIGHER ELEVATION SNOW.
&&
.UPDATE...REGIONAL DOPPLER RADAR SHOWING PRECIP MOVING THROUGH THE
BAY AREA TONIGHT AND ADVANCING INTO THE NORTHERN PORTIONS OF THE
DISTRICT. LATEST SURFACE OBSERVATIONS OUT OF MODESTO IS ALREADY
INDICATING LIGHT RAIN WITH RAIN POSSIBLE IN MERCED COUNTY AT ANY
TIME. SHORT RANGE MODELS...WHILE HAVING SOME DIFFICULTY...DO SHOW
SOME PRECIP OVER MERCED AND WEST FRESNO AND WEST MADERA COUNTIES
BY 10 PM PST...AND SLOWLY SPREADING SOUTHEAST TOWARD DAYBREAK.
SATELLITE IMAGERY IS SHOWING THE CENTER OF THE UPPER LOW NEAR
41N/129W THIS EVENING AND MOVING SOUTHEAST. MODELS SHOW THE CENTER
OF THE UPPER LOW APPROACHING THE BAY-AREA LATE TONIGHT AND THEN
TURNING SOUTH AND MOVING ALONG THE COAST. THEREFORE...WILL NOT
UPDATE THE FORECAST FOR PRECIP AND CURRENT WORDING STILL WORKS FOR
THE PRESENT EVENT. WILL EXPECT PRECIP TO OVERSPREAD THE DISTRICT
AFTER 04 AM PST WITH RAIN AND SNOW LIKELY AT THAT POINT. WILL
UPDATE WINTER STORM WATCH FOR THE KERN MOUNTAINS AND THE SPECIAL
WEATHER STATEMENT FOR THE DESERTS. WILL KEEP FORECAST AS IS AND
NOT UPDATE ANY ELEMENTS.
&&
.PREV DISCUSSION... /ISSUED 253 PM PST MON FEB 8 2010/
AN INSIDE SLIDER IS TAKING SHAPE ALONG 130W OFF THE OREG/NORCAL
COAST. THIS WILL PUSH SE ALONG THE CA COAST TUES AND TUES
EVENING...REACHING SOCAL EARLY WED. THIS WILL BE A QUICK MOVING
SYSTEM...AND OVERALL DONT EXPECT MUCH PRECIP. THE EXCEPTION COULD
BE THE KERN MTNS WHERE CONDS WILL BE RIGHT FOR A GOOD SNOW
EVENT...ESPECIALLY THE TEHACHAPIS...AND IN PARTICULAR...THE FORT
TEJON/FRAZIER PARK AREA AS AN EASTERLY FLOW DEVELOPS STRONG
OROGRAPHICS ON THE SOUTH AND EAST FACING SLOPES. CUDDY VALLEY CAN
BE ESPECIALLY HARD HIT IN THESE TYPES OF EVENTS.
NO HEADLINES WILL BE ISSUED FOR THE SRN SIERRA...AS THIS WILL BE A
COASTAL HUGGER...WHICH RARELY RESULTS IN SIGNIFICANT PRECIP.
HOWEVER THERE COULD BE SEVERAL INCHES OF SNOW AT AND ABOVE 3500
FEET OR SO. COULD BE SOME MIXING OF PRECIP OR CHANGE OVER TO SNOW
AT TIMES IN THE HIGH DESERTS NEAR 2500 FEET OR SO. STILL VERY HARD
TO SAY IF ACCUMULATING SNOW WILL OCCUR ON THE DESERT FLOOR TUES
NITE...BUT CERTAINLY NEAR AND OVER THE FOOTHILLS.
ALSO...AS THE COLD POOL ALOFT SLIDES BY JUST TO THE WEST TUES
AFTERNOON...ENOUGH INSTABILITY COULD BE GENERATED TO PRODUCE AN
ISOLATED TSTM FROM THE VALLEY INTO THE TEHACHAPIS...AND EVEN
DESERTS. MAIN THREAT OF TSTMS WILL BE TO THE WEST OVER THE COAST
RANGES...BUT VALLEY SB CAPES REACH ABOUT 500 J/KG IN THE AFTERNOON
WITH LI/S NEAR ZERO.
THE SLIDER WILL MOVE QUICKLY EAST ALONG THE OLD MEX/ARIZ BORDER
WED. THIS WILL BRING AN ABRUPT END TO ALL BUT A FEW LINGERING
MTN/DESERT SHOWERS BY NOON WED...IF NOT SOONER.
FLAT RIDGING IS THEN FCST BY MOST MED RANGE MODELS TO LAST
BASICALLY THE REMAINDER OF THE FCST. WEAKENING SYSTEMS THAT
PREVIOUSLY HAD BEEN FCST BY MODELS TO DRAG SOME WEAK FRONTS ACROSS
CENTRAL CA LATER THIS WEEK AND EARLY NEXT...HAVE JUST ABOUT
EVAPORATED. HAVE GONE TO A DRY FCST BEYOND WEDNESDAY...EXCEPT FOR
SOME SMALL POPS FROM FRESNO NORTH THURS NITE-FRI. BUT WOULDNT BE
SURPRISED TO SEE THESE GO AWAY AS WELL.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...MAINLY VFR THROUGH 06Z TUESDAY...AREAS
OF MVFR IN BR FROM 06Z-12Z TUESDAY AND IN RAIN AFTER 12Z TUESDAY.
IN THE SIERRA NEVADA AND TEHACHAPI MOUNTAINS...MVFR AND LCL IFR CIGS
AND MOUNTAIN OBSCURATIONS THROUGH 06Z TUESDAY...THEN LOWERING
CEILINGS WITH -RA SPREADING IN FROM THE NORTH AFTER 08Z TUESDAY. IN
THE KERN COUNTY DESERT...VFR THROUGH 18Z TUESDAY.
&&
.AIR QUALITY ISSUES...NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM TUESDAY
AFTERNOON THROUGH WEDNESDAY MORNING FOR THE KERN COUNTY MOUNTAINS
/CAZ095/.
&&
$$
PUBLIC...MOLINA
AVN/FW...DUDLEY
SYNOPSIS...PJ
WEATHER.GOV/HANFORD
000
FXUS65 KREV 090455 AAA
AFDREV
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
855 PM PST MON FEB 8 2010
.UPDATE...
NO UPDATES PLANNED. INITIAL BAND OF SNOW MOVING ONTO THE WEST
SLOPES OF THE SIERRA AND WILL CONTINUE TO SLOWLY PROGRESS EAST
OVERNIGHT. PERHAPS UP TO AN INCH OR TWO OF ACCUMULATION WITH
IT...GREATEST IN THE SIERRA NEAR THE CREST.
PARENT UPPER LOW WILL THEN DIG SOUTHEAST OFF THE COAST AND 00Z
MODELS ARE TRENDING EVEN FURTHER WEST. THIS APPEARS TO BE THE WAY
TO GO LOOKING AT WV IMAGERY. AS A RESULT...COLDEST TEMPS LOOK TO
STAY WEST OF THE AREA AND INSTABILITY MAY NOT BE THAT GREAT. SNOW
LEVELS MAY BRIEFLY RISE TO 5000 FEET WITH THIS FURTHER WEST TRACK
TUE AFTERNOON. IN ADDITION...THE EASTERLY WINDS WILL BE QUITE
LIGHT WITH ONLY 5-10 KTS AT 700 MB. THUS...THE EAST UPSLOPE EVENT
HIGHLIGHTED BELOW LOOKS LESS LIKELY ALTHOUGH COULD STILL SQUEEZE
OUT A COUPLE INCHES OR SO. AMOUNTS LOOK TO BE EVEN MORE LOCALIZED
THAN BEFORE SO MORE AREAS WILL LIKELY SEE LITTLE ACCUMULATION WITH
A FEW OTHERS COULD PICK UP A QUICK 2-3 INCHES IF THEY GET UNDER
HEAVIER SHOWERS.
WHILE I BELIEVE THE CURRENT PUBLISHED FORECAST IS A BIT
AGGRESSIVE...IT IS NOT THAT FAR OUT OF WHACK EITHER. PLENTY OF
UNCERTAINTY WAS MENTIONED...AND RIGHT NOW THERE IS A MUCH HIGHER
PROBABILITY THAT THE SNOW RECEIVED WILL BE LESS THAN FCST. WILL
NOT CHANGE DUE TO UNCERTAINTY AND LET MID SHIFT MAKE FINAL CALL
FOR TOMORROW. WALLMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 229 PM PST MON FEB 8 2010/
SHORT TERM - / TONIGHT THROUGH THURSDAY / ...
MAIN ISSUE FOR THE NEXT 24-30 HOURS IS THE COLD LOW DROPPING SOUTH
ALONG THE CALIFORNIA COAST. TRACK OF THE LOW WILL KEEP MOST OF
THE SHOWERS WEST OF THE SIERRA. HOWEVER AN INCREASE IN
MOISTURE...INSTABILITY AND A LOW TO MID LEVEL EASTERLY FLOW WILL
BRING SHOWERS TO THE SIERRA AND WESTERN NEVADA THROUGH TUESDAY
NIGHT.
MID-UPPER LEVEL MOISTURE AND DIFLUENT FLOW ALOFT AHEAD OF THE
SYSTEM WILL BRING SHOWERS TO THE NORTHERN SIERRA AND NORTHWEST
NEVADA AS EARLY AS THIS EVENING. SNOW LEVELS WILL DROP TO VALLEY
FLOORS BY EARLY TUESDAY MORNING...SO MOST OF THE SHOWER ACTIVITY
WILL BE SNOW.
THE BEST INSTABILITY DOES NOT REACH THE RENO-TAHOE AREA UNTIL
TUESDAY MORNING. WITH THE CONVECTIVE NATURE OF THE EVENT...IT IS
DIFFICULT TO PLACE WHERE SHOWERS/SNOW BANDS WILL BE HEAVIEST. DO
NOT EXPECT WIDESPREAD SNOW ACCUMULATIONS IN THE RENO-CARSON
AREA...SO IMPACTS TO THE MORNING COMMUTE ARE MINIMAL AT THIS
TIME. HOWEVER LOCATIONS AFFECTED BY SNOW SHOWERS COULD RECEIVE AN
INCH OR TWO OF SNOW IN A SHORT PERIOD OF TIME.
CONCERNS INCREASE TUESDAY AFTERNOON AND TUESDAY EVENING AS SEVERAL
FACTORS COINCIDE. A BIT OF SURFACE WARMING WILL INCREASE
INSTABILITY AS MOISTURE WRAPS AROUND THE LOW AND THE COLDEST AIR
ALOFT PASSES OVER THE EASTERN SIERRA. MODELS DROP THE LIFTED
INDEX TO -1...WITH 100-200 J/KG OF CAPE THROUGH THE MOIST UNSTABLE
LAYER OVER THE EASTERN SIERRA AND FAR WESTERN NEVADA. BY THIS
TIME THE LOW IS SOUTH OF MONTEREY BAY...TURNING THE LOW AND MID
LEVEL FLOW TO THE EAST-NORTHEAST. THIS PRODUCES A FAVORABLE
ENVIRONMENT FOR AN UPSLOPE EVENT ALONG THE EAST SLOPES SOUTH OF
US-50. LOCATIONS THAT COULD RECEIVE A FEW HOURS OF LIGHT TO MODERATE
SNOW ARE...DOUGLAS...SOUTHERN LYON...WESTERN MINERAL...ALPINE AND
MONO COUNTIES. DEPENDING ON THE LENGTH OF THE UPSLOPE EVENT
AMOUNTS UP TO 6 INCHES ARE POSSIBLE...ESPECIALLY FOR ALPINE AND
MONO COUNTIES.
SHORT WAVE RIDGE PASSES OVER THE AREA WEDNESDAY INTO EARLY
THURSDAY FOR DRIER CONDITIONS. HIGHS WEDNESDAY SHOULD WARM SEVERAL
DEGREES WITH RIDGE AXIS OVER WESTERN NEVADA AND A LIGHT SOUTH TO
SOUTHWEST SURFACE FLOW. CLOUDS WILL INCREASE THURSDAY NORTH OF
US-50 AS THE NEXT PACIFIC WAVE NEARS THE COAST. LIGHT WARM AIR
ADVECTION RAIN/SNOW IS POSSIBLE FOR LASSEN AND NORTHERN WASHOE
COUNTIES THURSDAY AFTERNOON. BRONG
LONG TERM (THURSDAY NIGHT - MONDAY)...
BASED ON THE 5-DAY MEAN 500MB HEIGHTS FROM GFS/EC, OVERALL PATTERN
DURING THE LONG TERM IS CHARACTERIZED BY A STRONG JET OVER THE
CENTRAL PACIFIC WITH DOWNSTREAM DIRTY RIDGE OVER WRN NOAM.
OCCASIONAL WEAK SYSTEMS WILL STILL AFFECT THE REGION, BUT NOTHING
MAJOR. TELECONNECTIONS WITH NEGATIVE ANOMALY OVER CNTRL ALEUTIANS
SUGGEST SLIGHTLY ABV NORMAL PRECIP IN NRN SIERRA. CONFIDENCE LEVELS
IN THE LONG TERM RANGE FROM HIGH (4/5) EARLY IN THE PERIOD TO
LOW/MODERATE (2/5) BY MONDAY...AS NCEP RMOP PRODUCTS SHOW A LOW
PREDICTABILITY PATTERN DEVELOPING BY EARLY NEXT WEEK WITH NO MAJOR
ANOMALIES TO LATCH ONTO.
WEAK UPPER TROF EXPECTED TO MOVE INTO THE REGION THURS NGT INTO
FRIDAY, WITH DIFFERENCES IN LATITUDINAL POSN OF THE LOW. MUCH OF THE
PRECIP WOULD LIKELY FALL THURS NGT IN THE SIERRA, MAINLY N OF TVL
PER GEFS. SPILLOVER UNCERTAIN THOUGH RELATIVELY DEEP MOISTURE WOULD
SUGGEST AT LEAST A FEW SHOWERS INTO WRN NV. EXPECTING SNOW LEVELS TO
FALL TO ROUGHLY 5000-5500 FT BASED ON SOUNDINGS AND 700MB TEMPS.
RIDGING FCST TO OVERSPREAD THE AREA SAT/SUN WITH RAPIDLY WARMING
TEMPS, ESPECIALLY AT RIDGE TOP LEVELS. SHOULD BE A RELATIVELY
TRANQUIL WEEKEND WITH GOOD TRAVEL CONDITIONS. EC AND GFS BRING A
WEAKER SYSTEM INTO THE REGION MON. QPF VALUES ARE QUITE LOW AND GEFS
POPS ARE ALMOST NON-EXISTENT. WOULD BE INCLINED TO DECREASE ONGOING
CHC POPS, HOWEVER LOWER PREDICTABILITY ENVIRONMENT AND TIMING
DIFFERENCES PRECLUDE MAKING CHANGES AT THIS TIME.
CS
AVIATION...
COLD UNSTABLE SYSTEM FCST TO DROP INTO CA/NV TUESDAY AND TUESDAY
NIGHT. PRIMARY AVIATION IMPACT WILL BE FROM SNOW AND REDUCED
CIGS/VSBYS. WINDS ARE NOT A CONCERN. PRECIP WILL BE MORE SHOWERY
WITH THE UNSTABLE ATMOSPHERE, THEREFORE IT WILL BE HARD TO PREDICT
EXACT TIMING OF LOWER CIGS/VSBYS MORE THAN A FEW HOURS OUT. ALSO,
SLIGHT CHANGES IN THE PATH OF THE UPPER LOW WILL HAVE A BIG IMPACT
ON PRECIP COVERAGE OVER THE SIERRA AND WRN NV.
THEREFORE CONFIDENCE IN THE TAFS TODAY IS ONLY MODERATE (3/5) AND I
HAVE KEPT THEM RATHER GENERAL WITH NO TEMPO GROUPS. LIKELIHOOD OF
SEEING PERIODS OF LIFR CONDS IN +SHSN IS ABOUT 25% AT RNO AND 70% AT
TVL/TRK BETWEEN ROUGHLY 09Z/09 AND 00Z/10. SNOW MAY IMPACT THE
TUESDAY MORNING DEPARTURES OUT OF RNO.
CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KMTR 090440
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
840 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 8:30 PM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
A FEW BANDS OF LIGHT SHOWERS HAVE MOVED ACROSS THE SAN FRANCISCO AND
MONTEREY BAY AREAS THIS EVENING WITH RAINFALL AMOUNTS LESS THAN 0.20
INCH. THESE SHOWERS ARE AHEAD OF THE MAIN SYSTEM WHICH IS DEEPENING
OFF THE NORTHERN CALIFORNIA COAST AT THIS TIME AS IT MOVES SOUTH-
SOUTHEASTWARD. COLD AIR WITH THIS SYSTEM WILL LOWER SNOW LEVELS TO
AROUND 2500 FEET WITH 2-3 INCHES OF SNOW POSSIBLE BELOW 3000 FEET ON
TUESDAY. ABOVE 3000 FEET UP TO 7 INCHES ARE POSSIBLE. THEREFORE...A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR ELEVATIONS ABOVE 2500
FEET FOR TUESDAY BETWEEN 6 AM AND 10 PM. AS THE SYSTEM DEEPENS OVER
THE NEXT 24 HOURS THE COLD AIR ALOFT WILL COMBINE WITH THE DYNAMICS
OF THE SYSTEM TO PRODUCE ISOLATED THUNDERSTORMS...WHICH MAY PRODUCE
BRIEF HEAVY RAIN/SNOW...SMALL HAIL AND GUSTY WINDS. WHEN THE COLD
FRONT MOVES THROUGH THE REGION DURING THE DAY ON TUESDAY WINDS WILL
PICK UP A BIT AND BECOME GUSTY IN THE MOUNTAINS AND HILLS. THE
MOISTURE ASSOCIATED WITH THIS SYSTEM IS LIMITED...ONLY A SMALL AREA
OF 0.88 INCH OF PRECIPITABLE WATER ON THE AMSU WITH THE MAJORITY OF
PW AROUND 0.70 INCH. ERGO...MOST LOCATIONS WILL EXPERIENCE LESS THAN
1/2 INCH WITH UP TO AN INCH POSSIBLE OVER THE HIGHER TERRAIN. ALSO...
THE COLD AIR WILL PLACE AFTERNOON HIGHS 5 TO 10 DEGREES COOLER THEN
CLIMATOLOGICAL NORMALS. AS THE SYSTEM CONTINUES ITS SOUTH-
SOUTHEASTWARD PROGRESSION TUESDAY NIGHT PARTIAL CLEANING IS EXPECTED
ALLOWING THE COLDEST VALLEY LOCATIONS TO DROP BELOW FREEZING WITH
AREAS OF FROST.
WEAK RIDGING FOR WEDNESDAY WILL FOLLOW THE TROUGH BRINGING A WARMER
AND DRY AIRMASS. HOWEVER...IT WILL BE SHORT-LIVED AS THE NEXT SYSTEM
WILL SQUASH THE RIDGE AS ITS HEADS FOR CALIFORNIA. THE MODELS ARE
INDICATING IT IS A FAST MOVER AND WILL JUST BRUSH BY NORTHERN AND
CENTRAL CALIFORNIA THURSDAY INTO FRIDAY IN A TWO WAVE SERIES.
NEITHER WAVE LOOKS IMPRESSIVE FOR US SINCE MOISTURE IS LIMITED AND WE
ARE ON THE SOUTHERN END OF THE WAVES. AT THIS TIME IT LOOKS LIKE
THESE TWO WAVES MAY PRODUCE UP TO AN INCH OF RAIN IN THE HIGHER
TERRAIN AND LESS THAN 1/2 INCH IN THE VALLEY LOCATIONS.
AFTER FRIDAY...A RIDGE DEVELOPS OVER CALIFORNIA KEEPING THE STORM
TRACK JUST NORTH OF THE REGION. AT THIS POINT WILL NOT MENTION RAIN
IN THE FORECAST FOR THE WEEKEND...BUT WILL REINTRODUCE THE
POSSIBILITY OF RAIN SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 4:31 PM MONDAY...RADAR SHOWS LINE OF
PRECIPITATION APPROACHING THE SFO BAY AREA BUT GROUND OBSERVATIONS
INDICATE VIRGA OR LIGHT PRECIPITATION. WET RUNWAYS ARE NOT EXPECTED
FROM THIS EPISODE.
LOW CLOUDS HAVE BLANKETED THE SFO BAY AREA THROUGH THE DAY.
APPROACHING SYSTEM IS EXPECTED TO MIX OUT THE LOW CLOUDS. ESTIMATED
TIME OF CLEARING IS 02-03Z SO THERE MAY BE A LITTLE BREAK FOR THE
AIRPORT EVENING RUSH HOUR. LOW CLOUDS WILL RETURN EARLY TUESDAY
MORNING AS SHOWERS FROM THE SYSTEM MOVE INTO THE AREA.
VICINITY OF KSFO...MVFR CIGS030 WITH A FEW LIGHT SHOWERS BECOMING VFR
SCT035-045 BY 02-03Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS.
SURFACE WINDS SW-W 5-10KTS. MVFR WITH CIGS/VSBYS IN SHOWERS AND
WET RUNWAYS BY 15Z TUESDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 THROUGH THE EVENING.
CIGS MAY BRIEFLY RISE ABOVE 4000 FEET BETWEEN 02-06Z. SHOWERS BY 16Z
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: EVANS
AVIATION/MARINE: GUDGEL/W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSGX 090436
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST MON FEB 8 2010
.SYNOPSIS...COLD UPPER LEVEL LOW PRESSURE APPROACHING FROM THE
NORTHWEST WILL BRING AN INCREASING CHANCE OF SHOWERS...BECOMING
LIKELY TUESDAY NIGHT INTO WEDNESDAY. THE SNOW LEVEL WILL LOWER TO
NEAR 3000 FEET. THERE COULD ALSO BE THUNDERSTORMS. DRY THURSDAY. A
WEAK LOW MOVING PAST TO THE NORTH COULD BRING A FEW SHOWERS TO THE
NORTHERN AREAS FRIDAY. FAIR AND WARMER THIS WEEKEND AND EARLY NEXT
WEEK UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-THURSDAY)...THERE WERE SCT TO LOCALLY BKN
CLOUDS THIS EVENING...MAINLY NEAR THE MOUNTAINS. THE 00Z NKX
SOUNDING SHOWED THE RESIDUAL LOW LEVEL MOISTURE WITH DRIER NW TO W
WINDS ALOFT. WEAK ONSHORE GRADIENTS.
A COLD UPPER LOW APPROACHING FROM THE NW WILL MOVE CLOSE TO IF NOT
DIRECTLY OVER SRN CA TUESDAY NIGHT. THIS WILL BRING INCREASING
CLOUDINESS EARLY TUESDAY WITH A CHANCE OF SHOWERS. THE SHOWERS WILL
BECOME MORE LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING WHEN THEY
WILL BECOME OCCASIONALLY MODERATE TO HEAVY. THERE IS A SLIGHT CHANCE
OF THUNDERSTORMS WITH HAIL TUESDAY NIGHT THROUGH WEDNESDAY MORNING
AS VERY COLD MID LEVEL AIR DESTABILIZES THE ATMOSPHERE. THERE COULD
ALSO BE WATERSPOUTS AND FUNNEL CLOUDS.
RAINFALL TOTALS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE OF
THE PRECIPITATION. GENERAL RAINFALL ESTIMATES RANGE FROM ABOUT HALF
TO ONE INCH WEST OF THE MOUNTAINS WITH ONE TO TWO INCHES ON THE
COASTAL MOUNTAIN SLOPES AND UP TO ABOUT HALF AN INCH IN THE DESERTS.
HOWEVER...THERE COULD BE LOCAL LARGER AMOUNTS.
SNOW LEVELS WILL BE QUITE LOW...LOWERING TO NEAR 3000 FEET AND
LOCALLY TO 2500 FEET LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING.
HOWEVER...THE EXACT TRACK OF THE LOW IS STILL UNCERTAIN AND IF IT
REMAINS FARTHER OFFSHORE THEN SNOW LEVELS WILL NOT GET AS LOW.
WIDESPREAD SNOW ACCUMULATIONS SHOULD RANGE FROM ABOUT HALF A FOOT TO
A FOOT WITH LOCAL LARGER AMOUNTS. SNOW WILL AFFECT THE MOUNTAIN
PASSES INCLUDING THE CAJON PASS IN THE SAN BERNARDINO MOUNTAINS AND
INTERSTATE 8 THROUGH THE SAN DIEGO MOUNTAINS.
THE SHOWERS WILL TAPER OFF WEDNESDAY AFTERNOON AND EVENING.
HOWEVER...WRAP AROUND MOISTURE AND ISLAND EFFECT SHOWERS COULD
CONTINUE TO IMPACT THE AREA. MAX TEMPS WILL DROP TO ABOUT 10 TO
20 DEGREES BELOW SEASONAL AVERAGES WEDNESDAY. DRY AND A WARMER
THURSDAY.
&&
.LONG TERM (FRIDAY-MONDAY)...A WEAK UPPER LOW WILL MOVE PAST TO THE
NORTH FRIDAY. THIS WILL BRING MORE CLOUDS AND A SLIGHT CHANCE OF
LIGHT SHOWERS TO THE NRN AREAS. FAIR AND WARMER THIS WEEKEND AND
EARLY NEXT WEEK UNDER HIGH PRESSURE. MAX TEMPS SHOULD GET NEAR TO A
LITTLE ABOVE SEASONAL AVERAGES.
&&
.AVIATION...
090430Z...PATCHY STRATUS CONTINUES OVER INLAND AREAS BETWEEN FL040
AND FL050. EXPECT IT WILL REMAIN SCT-LCLLY BKN OVERNIGHT WITH VFR
CONDITIONS PREVAILING...EXCEPT FOR PATCHY RADIATION FOG DEVELOPING
NEAR SUNRISE IN THE USUAL LOCATIONS SUCH AS KCNO...KAJO AND KRNM.
EXPECT AN INCREASE IN CLOUDS WITH MULTIPLE LAYERS AT OR ABOVE FL040
DEVELOPING DURING THE DAY TUESDAY. THEN BASES LOWERING WITH SCT -RW
BREAKING OUT AFTER 00Z WED.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR THE MOUNTAINS.
&&
$$
PUBLIC...ATKIN
AVIATION...JAD
000
FXUS66 KSGX 090435
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
233 PM PST MON FEB 8 2010
.SYNOPSIS...COLD UPPER LEVEL LOW PRESSURE APPROACHING FROM THE
NORTHWEST WILL BRING AN INCREASING CHANCE OF SHOWERS...BECOMING
LIKELY TUESDAY NIGHT INTO WEDNESDAY. THE SNOW LEVEL WILL LOWER TO
NEAR 3000 FEET. THERE COULD ALSO BE THUNDERSTORMS. DRY THURSDAY. A
WEAK LOW MOVING PAST TO THE NORTH COULD BRING A FEW SHOWERS TO THE
NORTHERN AREAS FRIDAY. FAIR AND WARMER THIS WEEKEND AND EARLY NEXT
WEEK UNDER HIGH PRESSURE.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TONIGHT-THURSDAY)...THERE WERE SCT TO LOCALLY BKN
CLOUDS THIS EVENING...MAINLY NEAR THE MOUNTAINS. THE 00Z NKX
SOUNDING SHOWED THE RESIDUAL LOW LEVEL MOISTURE WITH DRIER NW TO W
WINDS ALOFT. WEAK ONSHORE GRADIENTS.
A COLD UPPER LOW APPROACHING FROM THE NW WILL MOVE CLOSE TO IF NOT
DIRECTLY OVER SRN CA TUESDAY NIGHT. THIS WILL BRING INCREASING
CLOUDINESS EARLY TUESDAY WITH A CHANCE OF SHOWERS. THE SHOWERS WILL
BECOME MORE LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING WHEN THEY
WILL BECOME OCCASIONALLY MODERATE TO HEAVY. THERE IS A SLIGHT CHANCE
OF THUNDERSTORMS WITH HAIL TUESDAY NIGHT THROUGH WEDNESDAY MORNING
AS VERY COLD MID LEVEL AIR DESTABILIZES THE ATMOSPHERE. THERE COULD
ALSO BE WATERSPOUTS AND FUNNEL CLOUDS.
RAINFALL TOTALS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE OF
THE PRECIPITATION. GENERAL RAINFALL ESTIMATES RANGE FROM ABOUT HALF
TO ONE INCH WEST OF THE MOUNTAINS WITH ONE TO TWO INCHES ON THE
COASTAL MOUNTAIN SLOPES AND UP TO ABOUT HALF AN INCH IN THE DESERTS.
HOWEVER...THERE COULD BE LOCAL LARGER AMOUNTS.
SNOW LEVELS WILL BE QUITE LOW...LOWERING TO NEAR 3000 FEET AND
LOCALLY TO 2500 FEET LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING.
HOWEVER...THE EXACT TRACK OF THE LOW IS STILL UNCERTAIN AND IF IT
REMAINS FARTHER OFFSHORE THEN SNOW LEVELS WILL NOT GET AS LOW.
WIDESPREAD SNOW ACCUMULATIONS SHOULD RANGE FROM ABOUT HALF A FOOT TO
A FOOT WITH LOCAL LARGER AMOUNTS. SNOW WILL AFFECT THE MOUNTAIN
PASSES INCLUDING THE CAJON PASS IN THE SAN BERNARDINO MOUNTAINS AND
INTERSTATE 8 THROUGH THE SAN DIEGO MOUNTAINS.
THE SHOWERS WILL TAPER OFF WEDNESDAY AFTERNOON AND EVENING.
HOWEVER...WRAP AROUND MOISTURE AND ISLAND EFFECT SHOWERS COULD
CONTINUE TO IMPACT THE AREA. MAX TEMPS WILL DROP TO ABOUT 10 TO
20 DEGREES BELOW SEASONAL AVERAGES WEDNESDAY. DRY AND A WARMER
THURSDAY.
&&
.LONG TERM (FRIDAY-MONDAY)...A WEAK UPPER LOW WILL MOVE PAST TO THE
NORTH FRIDAY. THIS WILL BRING MORE CLOUDS AND A SLIGHT CHANCE OF
LIGHT SHOWERS TO THE NRN AREAS. FAIR AND WARMER THIS WEEKEND AND
EARLY NEXT WEEK UNDER HIGH PRESSURE. MAX TEMPS SHOULD GET NEAR TO A
LITTLE ABOVE SEASONAL AVERAGES.
&&
.AVIATION...
090430Z...PATCHY STRATUS CONTINUES OVER INLAND AREAS BETWEEN FL040
AND FL050. EXPECT IT WILL REMAIN SCT-LCLLY BKN OVERNIGHT WITH VFR
CONDITIONS PREVAILING...EXCEPT FOR PATCHY RADIATION FOG DEVELOPING
NEAR SUNRISE IN THE USUAL LOCATIONS SUCH AS KCNO...KAJO AND KRNM.
EXPECT AN INCREASE IN CLOUDS WITH MULTIPLE LAYERS AT OR ABOVE FL040
DEVELOPING DURING THE DAY TUESDAY. THEN BASES LOWERING WITH SCT -RW
BREAKING OUT AFTER 00Z WED.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR THE MOUNTAINS.
&&
$$
PUBLIC...ATKIN
AVIATION...JAD
000
FXUS66 KLOX 090433
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PST MON FEB 8 2010
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TUESDAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOL TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK...WITH THE EXCEPTION OF SOME LIGHT SHOWERS
POSSIBLE ON FRIDAY.
&&
.SHORT TERM (TONIGHT-THU)...
VIGOROUS UPPER LOW OFF THE OREGON COAST THIS EVENING WAS BEGINNING
TO DROP SWD PARALLEL TO THE WEST COAST. EARLIER...THE WRF SHOWED A
SLIGHTLY FARTHER W TRACK WITH THIS SYSTEM...KEEPING IT OVER WATER AS
IT PASSES JUST TO THE W OF THE FCST AREA TUESDAY AFTERNOON AND
TUESDAY NIGHT. THE GFS IS ALSO FARTHER W WITH ITS TRACK. THE TRACK
FARTHER OFF THE COAST WILL ALLOW THE SYSTEM TO PICK UP SOME MOISTURE
FROM THE PACIFIC. WHILE PRECIPITABLE WATER VALUE ARE NOT EXCESSIVELY
HIGH DUE TO THE COLD NATURE OF THE STORM...THEY STILL POP UP TO
BETWEEN .75 AND .80 JUST OFF THE COAST TUE. IN ADDITION...THE TRACK
PLACES THE FCST AREA UNDER THE FAVORABLE NE QUADRANT OF THE UPPER
LOW FOR A WHILE TUE AFTERNOON AND EVENING...WITH FAIRLY IMPRESSIVE
UPR LVL DIFFLUENCE OF HEIGHTS ALOFT...A HEALTHY AND FAIRLY DEEP
OMEGA FIELD...AND SOME SLY LOW LVL FLOW...PARTICULARLY ACROSS LOS
ANGELES...VENTURA AND SERN SBA COUNTIES. IN ADDITION...THE WRF SHOWS
LIFTED INDEX VALUES BELOW ZERO ACROSS MUCH OF THE REGION TUE
AFTERNOON AND EVENING. WITH A MORE FAVORABLE TRACK OVER THE
WATER...BETTER SLY LOW LEVEL FLOW...DEEPER MOISTURE AND LIFT...
AND AN INCREASED THREAT OF TSTMS...HAVE GONE AHEAD WITH A FLASH
FLOOD WATCH FOR THE RECENT BURN AREAS OF L.A. AND SBA COUNTIES.
THERE IS THE POTENTIAL THAT RAINFALL RATES COULD REACH ONE HALF
INCH TO ONE INCH PER HOUR...EXCEEDING THRESHOLDS DEEMED BY THE USGS
TO BE SUFFICIENT TO CAUSE FLASH FLOODING AND MUD AND DEBRIS FLOWS IN
AND BELOW THE RECENT BURN AREAS.
THE REMAINDER OF THE DISCUSSION STILL HOLDS TRUE...ALTHOUGH IF THE
TRACK OF THE UPPER LOW IS FARTHER OFF THE COAST...SNOW LEVELS WILL
HAVE TO BE ADJUSTED UPWARD A BIT. THAT WILL BE ASSESSED BY LATER
SHIFTS.
FROM PREVIOUS DISCUSSION...
SHOWERS WILL BECOME LIKELY ACROSS THE CENTRAL COAST EARLY TUESDAY
MORNING...THEN ARE EXPECTED TO BECOME WIDESPREAD ACROSS THE FORECAST
AREA BY TUESDAY AFTERNOON. DURING THIS TIME...MODEL CROSS SECTIONS
SHOW DEEPENING MOISTURE AND INCREASING DYNAMICS ACROSS THE REGION.
THERE IS ALSO RAPID COLD AIR ADVECTION ALOFT...WITH VERY IMPRESSIVE
500 MB TEMPERATURES OF -32 DEGREES AT THE CORE OF THE UPPER LOW
CENTER! THIS COLD CORE LOW PRESSURE CENTER IS EXPECTED TO TRACK
RIGHT OVER THE FORECAST AREA TUESDAY NIGHT. AS THE COLDER AIR
FILTERS INTO THE AREA...LOOK FOR INCREASING INSTABILITY WITH
LIFTED INDEX VALUES OF 0 TO -2. THIS TYPE OF PATTERN CERTAINLY
LOOKS CONDUCIVE TO THUNDERSTORM DEVELOPMENT...WITH LOTS OF SMALL
HAIL REPORTS LIKELY. WITH FAIRLY IMPRESSIVE DYNAMICS AND SUCH
COLD AIR ALOFT...NOT OUT OF THE QUESTION THAT SOME HAIL COULD APPROACH
SEVERE LIMITS. IN ADDITION TO HAIL...ANY THUNDERSTORM THAT DEVELOPS
WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS AND BRIEF HEAVY
DOWNPOURS. DUE TO THE CYCLONIC FLOW ALOFT AND UNSTABLE AIR MASS...
THERE WILL ALSO BE THE POTENTIAL FOR WATERSPOUTS OVER THE COASTAL
WATERS...WHICH HAS BEEN HIGHLIGHTED IN A MARINE WEATHER STATEMENT.
THE BULK OF THE SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TUESDAY
AFTERNOON INTO TUESDAY EVENING...WITH SHOWERS LIKELY REMAINING ACROSS
LOS ANGELES COUNTY OVERNIGHT TUESDAY NIGHT. BY WEDNESDAY
MORNING...ALL MODELS AGREE ON DROPPING THE CLOSED LOW SOUTH AND EAST
OF FORECAST AREA...WITH WRAP AROUND MOISTURE CONTINUING THE THREAT
OF SHOWERS WELL INTO THE DAY WEDNESDAY ACROSS THE MOUNTAINS OF
LA/VTU COUNTIES AS WELL AS THE ANTELOPE VALLEY.
RAINFALL AMOUNTS ARE GENERALLY EXPECTED TO RANGE BETWEEN .50 AND 1.00
INCHES ACROSS COASTAL AND VALLEY AREAS...WITH UP TO 1.50 INCHES
POSSIBLE IN THE FOOTHILLS AND LOWER COASTAL SLOPES. DUE TO THE SHOWERY
NATURE OF THE PRECIPITATION...RAINFALL AMOUNTS ARE EXPECTED TO BE
QUITE VARIABLE. IT IS ALSO IMPORTANT TO REMEMBER THAT HIGHER
RAINFALL AMOUNTS CAN BE EXPECTED FOR THOSE AREAS UNDER
THUNDERSTORMS. AT THIS TIME...IT APPEARS THAT LOS ANGELES COUNTY
WILL LIKELY RECEIVE THE HIGHEST RAINFALL AMOUNTS...ESPECIALLY ACROSS
EASTERN SECTIONS...DUE TO THE BEST CYCLONIC FLOW PATTERN FOR THAT
AREA. THERE WILL BE THE POTENTIAL FOR HEAVIER SHOWERS AND
THUNDERSTORMS ACROSS THE RECENT BURN AREAS...ESPECIALLY LOS ANGELES
COUNTY. FOR THE STATION FIRE...THE BEST CHANCE FOR THE HEAVIER
SHOWERS IS EXPECTED TO OCCUR FROM MID AFTERNOON THROUGH EVENING ON
TUESDAY. RAINFALL RATES ARE GENERALLY EXPECTED TO BE LESS THAN .25
INCHES PER HOUR...BUT WE COULD SEE RATES LOCALLY AS HIGH AS .50
INCHES PER HOUR NEAR HEAVIER SHOWERS OR THUNDERSTORMS. LATER SHIFTS
MAY NEED TO ISSUE A FLASH FLOOD WATCH FOR THE RECENT BURN AREAS OF
LOS ANGELES COUNTY...ESPECIALLY IF THIS SYSTEM TAKES ON A MORE
OVER-WATER TRAJECTORY.
A MAJOR IMPACT OF THIS UPCOMING STORM WILL BE THE VERY LOW SNOW
LEVELS. INITIALLY...SNOW LEVELS ARE EXPECTED TO RANGE BETWEEN 3500
AND 4000 FEET TUESDAY...THEN LOWER QUICKLY TO AROUND 3000 FEET
ACROSS THE NORTHERN MOUNTAINS ON TUESDAY AFTERNOON AS THE COLDER AIR
SPILLS INTO THE REGION. THICKNESS VALUES BOTTOM OUT AT A VERY
IMPRESSIVE 530 DM OVERNIGHT ON TUESDAY NIGHT! AS A RESULT...LOOK FOR
SNOW LEVELS TO FALL TO BETWEEN 2000 AND 2500 FEET TUESDAY
NIGHT...POSSIBLY EVEN LOWER UNDER ANY THUNDERSTORMS. WRAP AROUND
MOISTURE WILL LIKELY BRING THE THREAT OF ADDITIONAL SHOWERS TO THE
MOUNTAINS (ESPECIALLY NORTH FACING SLOPES) AND ANTELOPE VALLEY
THROUGH MUCH OF THE DAY WEDNESDAY. WINTER STORM WATCHES WILL BE
POSTED FOR THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS...WHERE 6 TO
12 INCHES OF SNOW IS EXPECTED...WITH LOCAL AMOUNTS UP TO 16 INCHES
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. DUE TO
THE LOW SNOW LEVELS EXPECTED...MAJOR LOW ELEVATION TRAFFIC CORRIDORS
WILL LIKELY BE IMPACTED BY ACCUMULATING SNOW...INCLUDING INTERSTATE
5 NORTH OF CASTAIC AS WELL AS HIGHWAY 14 THROUGH THE SOLEDAD CANYON.
WINTER WEATHER ADVISORIES HAVE ALSO BEEN POSTED FOR THE MOUNTAINS OF
SLO/SBA COUNTIES...WHERE 3 TO 6 INCHES OF SNOW CAN BE EXPECTED.
THE UNUSUAL LOW SNOW LEVELS WILL LIKELY BRING ACCUMULATING SNOW TO
SUCH PLACES AS THE ANTELOPE VALLEY...CUYAMA VALLEY...INTERIOR VALLEYS
OF SLO COUNTY...AS WELL AS THE HIGHER PEAKS OF THE SANTA MONICA
MOUNTAINS. THESE AREAS MAY REQUIRE WINTER WEATHER ADVISORIES AS WE
DRAW CLOSER TO THE EVENT...FOR NOW JUST HIGHLIGHTED IN A SPECIAL
WEATHER STATEMENT. THIS SYSTEM HAS THE POTENTIAL TO BRING BRIEF SNOW
SHOWERS TO UNUSUAL LOCATIONS ACROSS THE SOUTHLAND TUESDAY
NIGHT...SUCH AS SOME OF THE FOOTHILL LOCATIONS IN LOS ANGELES AND
VENTURA COUNTIES. THE ATMOSPHERE WILL DRY OUT AND BEGIN TO MODIFY
ON THURSDAY.
.LONG TERM (FRI-MON)...
ANOTHER WEAK SYSTEM WILL BRING A CHANCE OF SHOWERS ON FRIDAY...MAINLY
NORTH OF POINT CONCEPTION. HOWEVER...MODELS HAVE BEEN CONTINUING TO
TREND DRIER WITH THIS SYSTEM WITH TIME. THEN DRY WEATHER IS EXPECTED
THROUGH THE REMAINDER OF THE WEEKEND WITH NEAR SEASONAL NORMALS
EXPECTED.
&&
.AVIATION...08/1930Z.
GOOD CONFIDENCE IN VFR TO LOCAL MVFR CONDITIONS LASTING AT MOST OR
ALL TAF SITES THROUGH TONIGHT. SOME OF THE COASTAL AND VALLEY TAF
SITES ARE CONTENDING WITH LOW CLOUDS THIS MORNING. ANOTHER STORM
SYSTEM WILL DESCEND UPON THE REGION ON TUESDAY...LEADING TO MVFR TO
ISOLATED IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION.
KLAX AND KBUR...VFR TO MVFR CONDITIONS WILL DETERIORATE TO MVFR TO
LOCAL IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION BY TUESDAY WITH
THE ADVANCE OF A COLD STORM SYSTEM.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...SWEET
SYNOPSIS...MEIER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 090310
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
810 PM MST MON FEB 8 2010
.SYNOPSIS...
EXPECT AN INCREASE IN MAINLY HIGH CLOUDS TUESDAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW
SHOWERS...AS WELL AS A SLIGHT CHANCE FOR A THUNDERSTORM...WILL OCCUR
OVER FAR SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY...AND MAINLY OVER SOUTHWEST
AND SOUTH-CENTRAL ARIZONA WEDNESDAY AND WEDNESDAY EVENING. DRIER
CONDITIONS WILL PREVAIL THURSDAY AS THE LOW MOVES OFF TO OUR
EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY CONDITIONS WITH
SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY THROUGH THE
UPCOMING WEEKEND.
&&
.DISCUSSION...
AREAS OF LOW CLOUDS ACROSS THE REGION MONDAY AFTERNOON...EXTENSIVE
OVER CENTRAL AND NORTHERN AZ...IS A TESTIMONY TO REMAINING BOUNDARY
LAYER MOISTURE FROM LAST SATURDAY NIGHT/EARLY SUNDAY MORNINGS STORM.
THIS CONCERNS US...BECAUSE OF THE NEXT SYSTEM BARRELING DOWN THE
WEST COAST TOWARD SOUTHERN CA FOR LATE TUESDAY NIGHT...AND OVER AZ
ON WEDNESDAY.
MODELS FORECAST STRONG UPPER LEVEL DYNAMICS OVER SOUTHERN CA LATE
TUESDAY EVENING...OR AROUND MIDNIGHT AZ TIME. FUNDAMENTALS SUGGEST
AN AGEOSTROPHIC COMPONENT TO THE FLOW...WHICH SHOULD DRAW REMAINING
BOUNDARY LAYER MOISTURE INTO THE DEVELOPING STORM.
THIS WILL BE A COLD STORM FOCUSED OVER SOUTHERN CA...INCLUDING OUR
FORECAST AREA OF SOUTHEAST CA. SNOW LEVELS HAVE THE POTENTIAL TO
FALL TO NEAR 2500 FEET BY EARLY WED MORNING IN SOUTHEAST CA...WITH
PERHAPS 2 TO 4 INCHES OF SNOW ABOVE 3000 FEET IN JOSHUA TREE
NATIONAL PARK...MAYBE MORE. A WINTER STORM WATCH IS POSTED FOR THE
TUE NIGHT/WED MORNING PERIOD FOR POSSIBLE HEAVY SNOW IN JOSHUA TREE
N.P.
AS A CAVEAT...EVEN THOUGH THE STORM WILL TRACK THROUGH SOUTHERN CA
TUE NIGHT...THERE ARE SMALL MODEL DIFFERENCES IN WITH RESPECT TO THE
EVENTUAL STORM TRACK THROUGH AZ. THE UPSTREAM DEVELOPING EASTERN
PACIFIC RIDGE WILL GOVERN THE EVENTUAL STORM TRACK THROUGH AZ. A
STRONGER UPSTREAM RIDGE MAY SERVE TO DEEPEN THE STORM INTO NORTHWEST
MEXICO...WITH THE BRUNT OF THE STORM ENERGY HEADING SOUTH. STAY
TUNED.
OTHERWISE...CURRENT FORECASTS LOOK OK. NO UPDATES PLANNED. PREVIOUS
DISCUSSION BELOW STILL APPLIES.
PREVIOUS DISCUSSION...
ALL SIGNS POINT TO A BRIEF BUT ACTIVE PERIOD OF WEATHER DURING THE
SHORT TERM...COMMENCING OVER THE WESTERN CWA TUESDAY NIGHT...AND
AFFECTING MUCH OF THE CENTRAL AND EASTERN CWA WEDNESDAY AND
WEDNESDAY NIGHT. SNOW LEVEL AND QPF WERE THE MOST SIGNIFICANT
CONSIDERATIONS DURING THIS PERIOD. STORM THAT WILL GENERATE THE
PERIOD OF ACTIVE WEATHER IS CURRENTLY TAKING SHAPE WEST OF THE
WASHINGTON-OREGON COAST...AND WITH PRONOUNCED UPSTREAM RIDGING
CURRENTLY TAKING PLACE NEAR 160W...THIS STORM WILL DIG QUICKLY
TOWARD THE SOUTH-SOUTHEAST NEXT 36 HRS. BY 00Z WEDNESDAY...500 MB
CENTER WILL BE NEAR OR JUST WEST OF THE SOUTH-CENTRAL CALIFORNIA
COAST...MOVE TO EXTREME SOUTHERN CALIFORNIA BY 12Z WEDNESDAY...AND
BE NEAR ORGAN PIPE NM BY 00Z THURSDAY. VERY IMPRESSIVE 12 HR 500 MB
HEIGHT FALL-RISE COUPLET TRACKS SOUTH NEAR CALIFORNIA COAST TUESDAY
AND TUESDAY NIGHT...WITH HEIGHT FALLS IN EXCESS OF 120 M/12 HRS...SO
GREATEST MASS ADJUSTMENT OCCURS OVER FAR WEST PORTION OF OUR CWA
(FAR SOUTHEAST CALIFORNIA) TUESDAY NIGHT. TIME SECTIONS FROM
ECMWF/GFS/NAM ALL DEPICT MDT/STRONG UPWARD VERTICAL MOTION TO
DEVELOP IN CONJUNCTION WITH DEEP MOIST LAYER AS THIS OCCURS...WITH
SNOW LEVEL FORECAST TO DROP RAPIDLY OVER JTNP TUESDAY NIGHT...TO AS
LOW AS BETWEEN 2500 AND 3000 FEET BY EARLY WEDNESDAY MORNING...GIVEN
1000-500 MB THICKNESS AND EXPLICIT MODEL SOUNDING FORECASTS.
CONDITIONAL INSTABILITY OCCURS AS WELL...GIVEN THETA-E PROFILE...SO
A BURST OF THUNDERSNOW IS NOT OUT OF THE QUESTION. SYSTEM WILL BE A
FAST MOVER...WITH ONLY A MODEST AMOUNT OF MOISTURE TO WORK WITH...
BUT IT STILL SEEMED PRUDENT TO ISSUE A WINTER STORM WATCH FOR JTNP
BASED ON EXPECTATION OF UNUSUALLY LOW SNOW LEVEL AND POTENTIAL FOR
ACCUMULATING SNOW DOWN TO 3000 FEET ELEVATION...AND THAT PRODUCT HAS
BEEN POSTED.
UPPER LOW MOVES EAST ALONG OR NEAR THE INTERNATIONAL BORDER
WEDNESDAY...WHERE 500 MB HEIGHT FALLS/MASS ADJUSTMENTS WILL BE
GREATEST. HIGHEST PROBABILITY FOR MEASURABLE PRECIPITATION (70-80%)
SHOULD BE OVER SOUTH-CENTRAL AND SOUTHEAST ARIZONA...SITUATED IN
NORTHEAST QUAD OF UPPER LOW AND JUST NORTH OF VERY STRONG
SUBTROPICAL JET. HPC QPF...ON THE ORDER OF ONE TENTH TO ONE THIRD
INCH OVER THE LOWER DESERT...AND ONE HALF TO THREE QUARTERS INCH
OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL AZ...LOOKS GOOD AND WAS
ACCEPTED. AS USUAL...ISOLATED HIGHER RAINFALL AMOUNTS WILL BE
POSSIBLE...ESPECIALLY WHERE ANY THUNDERSTORMS FORM. OVER HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...ACCUMULATING SNOW WILL BE LIKELY
ABOVE 5000 FEET ON WEDNESDAY...AND ABOVE 4500 FEET WEDNESDAY NIGHT.
ONLY FORECASTING SEVERAL INCHES OF SNOW IN SOUTHERN GILA COUNTY
ABOVE 4500 FEET WEDNESDAY NIGHT...SO HWO SEEMED SUFFICIENT TO COVER
THIS (FOR NOW). LOW QUICKLY MOVES EAST OF OUR AREA ON THURSDAY...
WITH STRONG SHORT WAVE RIDGE BUILDING OVERHEAD...SO RETAINED ONLY
SLIGHT CHANCE FOR MAINLY MORNING SHOWERS OVER HIGHER TERRAIN OF
SOUTH CENTRAL AZ. BELOW NORMAL DAYTIME HIGHS WILL PERSIST THE NEXT
FEW DAYS...WITH MAX TEMPS 10-12 DEGREES BELOW NORMAL ON
WEDNESDAY...THE COOLEST OF THE THREE DAYS.
IN EXTENDED...MODELS VARY ON WHAT WILL TRANSPIRE...BUT ALL GUIDANCE
SUPPORTS IDEA OF WARMER TEMPS FRIDAY INTO THE WEEKEND AS RIDGE
POSITION BECOMES ESTABLISHED NEAR THE WEST COAST. GFS BRINGS
ANOTHER UPPER LOW SOUTHEAST ACROSS THE FOUR CORNERS AND NM SATURDAY
NIGHT-SUNDAY...BUT ECMWF DOES NOT SUPPORT THAT SOLUTION. NO CHANGES
MADE TO THIS PERIOD OF THE FORECAST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX AND KIWA...
THROUGH 18Z TUE...SCT CLDS BASED NEAR 9-11 THSD MSL. LIGHT WIND.
BETWEEN 18Z TUE AND 06Z WED...INCREASING AND LOWERING CLOUDS. CLDS
BECOME BKN TO OVC NEAR 16 THSD MSL BY 22Z TUE. LIGHT WIND.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
THROUGH 12Z TUE...CLEAR SKIES. LIGHT WIND. BETWEEN 12Z TUE AND
06Z WED...INCREASING AND LOWERING CLOUDS. CLDS BECOME BKN TO OVC
NEAR 16 THSD MSL BY 18Z TUE. LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
MORNING CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ/DG
AVIATION...VASQUEZ
FIRE WEATHER...ELLIS
000
FXUS66 KMTR 090030
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
230 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 2:30 PM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
MOUNT VACA RADAR IS ALREADY STARTING TO INDICATE PRECIPITATION OFF
THE SONOMA COAST THIS AFTERNOON AS A WEAK UPPER LEVEL TROUGH
MOVES ONSHORE FROM THE WEST. RAINFALL IS EXPECTED TO MOSTLY BE
LIGHT TONIGHT WITH TOTALS UNDER .2". THESE SHOWERS ARE AN EARLY
PREVIEW OF THE MAIN EVENT FOR TOMORROW WHEN A STRONG TROUGH AND LOW
CENTER DIVE SOUTHWARD ALONG THE COAST. MODEL GUIDANCE CONTINUES TO
SHOW INSTABILITY WITH THIS FEATURE AS LIFTED VALUES GO NEGATIVE...
SOME CAPE...AND 925 MB WINDS PICK UP TO 30 KT. TEMPERATURES WILL BE
THE MAIN STORY AS 700 MB LEVELS DROP TO BETWEEN -10 AND -12C WHICH
ROUGHLY TRANSLATES TO A SNOW LEVEL AROUND 3000 FEET. HOWEVER...
LEVELS COULD LOCALLY BE AS LOW AS 2000 FEET WITH THE HEAVIEST
SHOWERS. SMALL HAIL CAN ALSO BE EXPECTED. UNFORTUNATELY STILL LOOKS
LIKE THE STRONGEST OF THE SHOWERS WILL MOVE INTO THE BAY AREA CLOSE
TO THE MORNING RUSH. ALTHOUGH THERE IS STILL A LITTLE UNCERTAINTY
WITH THE TRACK OF THE LOW...THE OVERALL CONSENSUS WOULD BRING THE
BEST PRECIPITATION FIELD TO THE COASTAL MOUNTAINS SOUTH OF SAN
FRANCISCO WHERE UP TO AN 1" IS NOT OUT OF THE QUESTION. A WINTER
WEATHER ADVISORY HAS ALSO BEEN ISSUED FOR 2-3" OF SNOW FOR 2500-3000
FEET AND UP TO 7" FOR ELEVATIONS ABOVE 3000 FEET. BIGGEST QUESTION
MARK CENTERS AROUND THE EAST BAY/DIABLO AREA WHERE THE BULK OF THE
COLD AIR WILL NOT QUITE MAKE IT AND THE HEAVIER PRECIPITATION IS
EXPECTED TO REMAIN SOUTH OF. WITH PLENTY OF CLOUDS THROUGH THE DAY
AND COOL AIR ADVECTING IN...HIGHS TOMORROW WILL STRUGGLE TO GET INTO
THE 50S. WITH SOME CLEARING EXPECTED TUESDAY NIGHT...ESPECIALLY OVER
THE NORTH BAY...LOWS SHOULD DROP BACK INTO THE LOW 30S FOR THE
COOLEST SPOTS ALONG WITH PATCHY FROST.
AFTER A DRY DAY ON WEDNESDAY...A WEAK TROUGH MOVES ONSHORE FOR
THURSDAY WITH A SECOND STRONGER FEATURE ON FRIDAY. EARLY QPF NUMBERS
HAVE 2 DAY TOTALS MOSTLY UNDER 1/2" FOR ALL METRO AREAS WITH HIGHER
TOTALS EXPECTED THE FURTHER NORTH YOU TRAVEL. SNOWFALL IS NOT
EXPECTED FROM THIS SYSTEM.
DRY WEATHER STILL ON TAP FOR THE WEEKEND.
&&
.AVIATION...AS OF 4:31 PM MONDAY...RADAR SHOWS LINE OF
PRECIPITATION APPROACHING THE SFO BAY AREA BUT GROUND OBSERVATIONS
INDICATE VIRGA OR LIGHT PRECIPITATION. WET RUNWAYS ARE NOT EXPECTED
FROM THIS EPISODE.
LOW CLOUDS HAVE BLANKETED THE SFO BAY AREA THROUGH THE DAY.
APPROACHING SYSTEM IS EXPECTED TO MIX OUT THE LOW CLOUDS. ESTIMATED
TIME OF CLEARING IS 02-03Z SO THERE MAY BE A LITTLE BREAK FOR THE
AIRPORT EVENING RUSH HOUR. LOW CLOUDS WILL RETURN EARLY TUESDAY
MORNING AS SHOWERS FROM THE SYSTEM MOVE INTO THE AREA.
VICINITY OF KSFO...MVFR CIGS030 WITH A FEW LIGHT SHOWERS BECOMING VFR
SCT035-045 BY 02-03Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS.
SURFACE WINDS SW-W 5-10KTS. MVFR WITH CIGS/VSBYS IN SHOWERS AND
WET RUNWAYS BY 15Z TUESDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 THROUGH THE EVENING.
CIGS MAY BRIEFLY RISE ABOVE 4000 FEET BETWEEN 02-06Z. SHOWERS BY 16Z
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: GUDGEL/W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 090024
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
230 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 2:30 PM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
MOUNT VACA RADAR IS ALREADY STARTING TO INDICATE PRECIPITATION OFF
THE SONOMA COAST THIS AFTERNOON AS A WEAK UPPER LEVEL TROUGH
MOVES ONSHORE FROM THE WEST. RAINFALL IS EXPECTED TO MOSTLY BE
LIGHT TONIGHT WITH TOTALS UNDER .2". THESE SHOWERS ARE AN EARLY
PREVIEW OF THE MAIN EVENT FOR TOMORROW WHEN A STRONG TROUGH AND LOW
CENTER DIVE SOUTHWARD ALONG THE COAST. MODEL GUIDANCE CONTINUES TO
SHOW INSTABILITY WITH THIS FEATURE AS LIFTED VALUES GO NEGATIVE...
SOME CAPE...AND 925 MB WINDS PICK UP TO 30 KT. TEMPERATURES WILL BE
THE MAIN STORY AS 700 MB LEVELS DROP TO BETWEEN -10 AND -12C WHICH
ROUGHLY TRANSLATES TO A SNOW LEVEL AROUND 3000 FEET. HOWEVER...
LEVELS COULD LOCALLY BE AS LOW AS 2000 FEET WITH THE HEAVIEST
SHOWERS. SMALL HAIL CAN ALSO BE EXPECTED. UNFORTUNATELY STILL LOOKS
LIKE THE STRONGEST OF THE SHOWERS WILL MOVE INTO THE BAY AREA CLOSE
TO THE MORNING RUSH. ALTHOUGH THERE IS STILL A LITTLE UNCERTAINTY
WITH THE TRACK OF THE LOW...THE OVERALL CONSENSUS WOULD BRING THE
BEST PRECIPITATION FIELD TO THE COASTAL MOUNTAINS SOUTH OF SAN
FRANCISCO WHERE UP TO AN 1" IS NOT OUT OF THE QUESTION. A WINTER
WEATHER ADVISORY HAS ALSO BEEN ISSUED FOR 2-3" OF SNOW FOR 2500-3000
FEET AND UP TO 7" FOR ELEVATIONS ABOVE 3000 FEET. BIGGEST QUESTION
MARK CENTERS AROUND THE EAST BAY/DIABLO AREA WHERE THE BULK OF THE
COLD AIR WILL NOT QUITE MAKE IT AND THE HEAVIER PRECIPITATION IS
EXPECTED TO REMAIN SOUTH OF. WITH PLENTY OF CLOUDS THROUGH THE DAY
AND COOL AIR ADVECTING IN...HIGHS TOMORROW WILL STRUGGLE TO GET INTO
THE 50S. WITH SOME CLEARING EXPECTED TUESDAY NIGHT...ESPECIALLY OVER
THE NORTH BAY...LOWS SHOULD DROP BACK INTO THE LOW 30S FOR THE
COOLEST SPOTS ALONG WITH PATCHY FROST.
AFTER A DRY DAY ON WEDNESDAY...A WEAK TROUGH MOVES ONSHORE FOR
THURSDAY WITH A SECOND STRONGER FEATURE ON FRIDAY. EARLY QPF NUMBERS
HAVE 2 DAY TOTALS MOSTLY UNDER 1/2" FOR ALL METRO AREAS WITH HIGHER
TOTALS EXPECTED THE FURTHER NORTH YOU TRAVEL. SNOWFALL IS NOT
EXPECTED FROM THIS SYSTEM.
DRY WEATHER STILL ON TAP FOR THE WEEKEND.
&&
.AVIATION...AS OF 4:30 PM MONDAY...LOW CLOUDS HAVE BLANKETED THE
SFO BAY AREA THROUGH THE DAY. APPROACHING SYSTEM IS EXPECTED TO
MIX OUT THE LOW CLOUDS. ESTIMATED TIME OF CLEARING IS 02-03Z SO
THERE MAY BE A LITTLE BREAK FOR THE AIRPORT EVENING RUSH HOUR.
LOW CLOUDS WILL RETURN EARLY TUESDAY MORNING AS SHOWERS FROM THE
SYSTEM MOVE INTO THE AREA.
VICINITY OF KSFO...MVFR CIGS030 BECOMING VFR SCT035-045 BY 02-03Z.
VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE WINDS SW-W
5-10KTS. MVFR WITH CIGS/VSBYS IN RAIN AND WET RUNWAYS BY 15Z
TUESDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 THROUGH THE EVENING.
CIGS MAY BRIEFLY RISE ABOVE 4000 FEET BETWEEN 02-06Z. SHOWERS BY 16Z
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: GUDGEL/W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 082342
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
440 PM MST MON FEB 8 2010
.SYNOPSIS...
EXPECT AN INCREASE IN MAINLY HIGH CLOUDS TUESDAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST. RAIN AND MOUNTAIN SNOW
SHOWERS...AS WELL AS A SLIGHT CHANCE FOR A THUNDERSTORM...WILL OCCUR
OVER FAR SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY...AND MAINLY OVER SOUTHWEST
AND SOUTH-CENTRAL ARIZONA WEDNESDAY AND WEDNESDAY EVENING. DRIER
CONDITIONS WILL PREVAIL THURSDAY AS THE LOW MOVES OFF TO OUR
EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY CONDITIONS WITH
SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY THROUGH THE
UPCOMING WEEKEND.
&&
.DISCUSSION...
ALL SIGNS POINT TO A BRIEF BUT ACTIVE PERIOD OF WEATHER DURING THE
SHORT TERM...COMMENCING OVER THE WESTERN CWA TUESDAY NIGHT...AND
AFFECTING MUCH OF THE CENTRAL AND EASTERN CWA WEDNESDAY AND
WEDNESDAY NIGHT. SNOW LEVEL AND QPF WERE THE MOST SIGNIFICANT
CONSIDERATIONS DURING THIS PERIOD. STORM THAT WILL GENERATE THE
PERIOD OF ACTIVE WEATHER IS CURRENTLY TAKING SHAPE WEST OF THE
WASHINGTON-OREGON COAST...AND WITH PRONOUNCED UPSTREAM RIDGING
CURRENTLY TAKING PLACE NEAR 160W...THIS STORM WILL DIG QUICKLY
TOWARD THE SOUTH-SOUTHEAST NEXT 36 HRS. BY 00Z WEDNESDAY...500 MB
CENTER WILL BE NEAR OR JUST WEST OF THE SOUTH-CENTRAL CALIFORNIA
COAST...MOVE TO EXTREME SOUTHERN CALIFORNIA BY 12Z WEDNESDAY...AND
BE NEAR ORGAN PIPE NM BY 00Z THURSDAY. VERY IMPRESSIVE 12 HR 500 MB
HEIGHT FALL-RISE COUPLET TRACKS SOUTH NEAR CALIFORNIA COAST TUESDAY
AND TUESDAY NIGHT...WITH HEIGHT FALLS IN EXCESS OF 120 M/12 HRS...SO
GREATEST MASS ADJUSTMENT OCCURS OVER FAR WEST PORTION OF OUR CWA
(FAR SOUTHEAST CALIFORNIA) TUESDAY NIGHT. TIME SECTIONS FROM
ECMWF/GFS/NAM ALL DEPICT MDT/STRONG UPWARD VERTICAL MOTION TO
DEVELOP IN CONJUNCTION WITH DEEP MOIST LAYER AS THIS OCCURS...WITH
SNOW LEVEL FORECAST TO DROP RAPIDLY OVER JTNP TUESDAY NIGHT...TO AS
LOW AS BETWEEN 2500 AND 3000 FEET BY EARLY WEDNESDAY MORNING...GIVEN
1000-500 MB THICKNESS AND EXPLICIT MODEL SOUNDING FORECASTS.
CONDITIONAL INSTABILITY OCCURS AS WELL...GIVEN THETA-E PROFILE...SO
A BURST OF THUNDERSNOW IS NOT OUT OF THE QUESTION. SYSTEM WILL BE A
FAST MOVER...WITH ONLY A MODEST AMOUNT OF MOISTURE TO WORK WITH...
BUT IT STILL SEEMED PRUDENT TO ISSUE A WINTER STORM WATCH FOR JTNP
BASED ON EXPECTATION OF UNUSUALLY LOW SNOW LEVEL AND POTENTIAL FOR
ACCUMULATING SNOW DOWN TO 3000 FEET ELEVATION...AND THAT PRODUCT HAS
BEEN POSTED.
UPPER LOW MOVES EAST ALONG OR NEAR THE INTERNATIONAL BORDER
WEDNESDAY...WHERE 500 MB HEIGHT FALLS/MASS ADJUSTMENTS WILL BE
GREATEST. HIGHEST PROBABILITY FOR MEASURABLE PRECIPITATION (70-80%)
SHOULD BE OVER SOUTH-CENTRAL AND SOUTHEAST ARIZONA...SITUATED IN
NORTHEAST QUAD OF UPPER LOW AND JUST NORTH OF VERY STRONG
SUBTROPICAL JET. HPC QPF...ON THE ORDER OF ONE TENTH TO ONE THIRD
INCH OVER THE LOWER DESERT...AND ONE HALF TO THREE QUARTERS INCH
OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL AZ...LOOKS GOOD AND WAS
ACCEPTED. AS USUAL...ISOLATED HIGHER RAINFALL AMOUNTS WILL BE
POSSIBLE...ESPECIALLY WHERE ANY THUNDERSTORMS FORM. OVER HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...ACCUMULATING SNOW WILL BE LIKELY
ABOVE 5000 FEET ON WEDNESDAY...AND ABOVE 4500 FEET WEDNESDAY NIGHT.
ONLY FORECASTING SEVERAL INCHES OF SNOW IN SOUTHERN GILA COUNTY
ABOVE 4500 FEET WEDNESDAY NIGHT...SO HWO SEEMED SUFFICIENT TO COVER
THIS (FOR NOW). LOW QUICKLY MOVES EAST OF OUR AREA ON THURSDAY...
WITH STRONG SHORT WAVE RIDGE BUILDING OVERHEAD...SO RETAINED ONLY
SLIGHT CHANCE FOR MAINLY MORNING SHOWERS OVER HIGHER TERRAIN OF
SOUTH CENTRAL AZ. BELOW NORMAL DAYTIME HIGHS WILL PERSIST THE NEXT
FEW DAYS...WITH MAX TEMPS 10-12 DEGREES BELOW NORMAL ON
WEDNESDAY...THE COOLEST OF THE THREE DAYS.
IN EXTENDED...MODELS VARY ON WHAT WILL TRANSPIRE...BUT ALL GUIDANCE
SUPPORTS IDEA OF WARMER TEMPS FRIDAY INTO THE WEEKEND AS RIDGE
POSITION BECOMES ESTABLISHED NEAR THE WEST COAST. GFS BRINGS
ANOTHER UPPER LOW SOUTHEAST ACROSS THE FOUR CORNERS AND NM SATURDAY
NIGHT-SUNDAY...BUT ECMWF DOES NOT SUPPORT THAT SOLUTION. NO CHANGES
MADE TO THIS PERIOD OF THE FORECAST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX AND KIWA...
LOW LEVEL MOISTURE IS SLOW TO DECREASE...IN FACT KSDL WENT OVC FOR
AWHILE THIS AFTN. BUT AS WEAK UPPER RIDGE AND STABLE AIRMASS LINGERS
OVERHEAD...OUR CLOUDS WILL PERSIST INTO THE EVENING HOURS. SCT/BKN
SC NOW EXPECTED WITH BASES NEAR 6-8 THSD FT. INCREASING MID/HIGH
CLOUDS FOR TUESDAY ASSOCIATED WITH NEXT PAC SYSTEM. LGT DIURNAL
WINDS THRU AT LEAST 09/1200Z.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY SOME INCREASING MID AND HI CLOUDS TONIGHT AND TUESDAY AS NEXT
PAC SYSTEM DEVELOPS FURTHER. GENERALLY LGT WINDS THRU AT LEAST
09/1200Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
MORNING CAZ030.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
000
FXUS66 KSTO 082255
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
255 PM PST MON FEB 8 2010
.DISCUSSION...
WEAK FRONT AND ELONGATING UPPER TROUGH MOVING ONSHORE THIS
AFTERNOON. NWS 8 DOPPLER RADAR MOSAIC BEGINNING TO PICK SOME LIGHT
RETURNS WEST OF THE FORECAST AREA. SYSTEM WILL MOVE THROUGH THE
INTERIOR THIS EVENING BRINGING A THREAT OF SOME LIGHT SHOWERS...
MAINLY OVER THE MOUNTAINS.
FOLLOWING QUICKLY BEHIND THIS IS THE DIGGING LOW/TROUGH FROM THE
GOA. MODELS DEVELOP SECONDARY UPPER LOW TONIGHT OFF THE SOUTHERN
OREGON COAST AND MOVE IT SOUTHWARD ALONG THE CALIFORNIA COAST
TOMORROW. BLENDED TPW SHOWING LESS MOISTURE FEED INTO THIS LOW THAN
EARLIER. ASSOCIATED SHOWERS POSSIBLE IN THE NORTHERN INTERIOR
TONIGHT SPREADING SOUTHWARD TUESDAY MORNING. MAIN COLD CORE ALOFT
REMAINS MOSTLY WEST OF THE AREA TUESDAY AND AS A RESULT...OVERALL
QPF AMOUNTS LOOK FAIRLY LIGHT. HOWEVER WITH CONVECTIVE NATURE OF THE
SYSTEM...POTENTIAL EXISTS FOR SOME LOCALLY HEAVIER SHOWERS AND A
SLIGHT CHANCE OF A THUNDERSTORM OVER WESTERN PORTIONS OF THE CWA.
18Z NAM BUFKIT AND 12Z GFS TRENDING DOWN ON PRECIP AT KBLU FROM
PREVIOUS RUNS. THUS WILL CONTINUE THE SPS FOR THE MOUNTAINS AS
OVERALL SNOW AMOUNTS LOOK TO BE JUST BELOW CRITERIA...HOWEVER
LOCALLY HIGHER ACCUMULATIONS POSSIBLE IN HEAVIER SHOWERS AND OVER
HIGHER TERRAIN. SNOW LEVELS FORECAST AROUND 3000 TO 4000 FEET IN THE
NORTHERN AND COASTAL MOUNTAINS AND 4000 TO 6000 FEET ALONG THE
SIERRA TUESDAY.
DECREASING CLOUDS TUESDAY NIGHT AS UPPER LOW TRACKS SOUTH OF THE
AREA AND SHORT WAVE RIDGING INCREASES SUBSIDENCE OVER NORCAL.
CLEARING SKIES WITH COLDER AMS WILL ALLOW GOOD RADIATIONAL COOLING
WITH 30S FOR THE CENTRAL VALLEY AND TEENS TO 20S IN THE HIGH COUNTRY.
DRIER WEATHER MODELED OVER INTERIOR NORCAL WEDNESDAY AS UPPER RIDGE
THE DOMINANT FEATURE THEN SOME LIGHT OVERRUNNING WARM FRONTAL PRECIP
POSSIBLE LATE WEDNESDAY NIGHT INTO THURSDAY MAINLY NORTH OF
INTERSTATE 80. PRECIP CHANCES INCREASE OVER THE CWA THURSDAY NIGHT
INTO FRIDAY AS FRONTAL SYSTEM MOVES INTO INTERIOR NORCAL.
PCH
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
PRECIPITATION WILL CONTINUE ON FRIDAY WITH THE TROUGH MOVING
THROUGH. SNOW LEVELS WITH THIS SYSTEM ARE EXPECTED TO BE AROUND
4000 TO 5000 FEET ON FRIDAY. WEAK RIDGING BUILDS IN OVER NORTHERN
CALIFORNIA BEHIND THE TROUGH ON FRIDAY NIGHT DIMINISHING THE
SHOWERS. RIDGE OF HIGH PRESSURE OVER THE AREA ON SATURDAY BRINGING A
BREAK IN THE PRECIPITATION AND POSSIBLY THE RETURN OF FOG AND LOW
CLOUDS TO THE VALLEYS. TEMPERATURES ARE EXPECTED TO WARM INTO THE
LOWER 60S IN THE VALLEY AND IN THE 40S IN THE MOUNTAINS ON SATURDAY
AND SUNDAY. AN UPPER LEVEL GOLF OF ALASKA TROUGH APPROACHES THE
PACIFIC NORTHWEST COAST ON SUNDAY PUSHING THE RIDGE OF TO THE EAST.
WARM AIR ADVECTION PRECIPITATION MAY BE POSSIBLE IN THE SHASTA
COUNTY MOUNTAINS ON SUNDAY AS THIS SYSTEM APPROACHES. THIS TROUGH
MOVES INLAND ON SUNDAY NIGHT BRINGING A CHANCE OF PRECIPITATION
SUNDAY NIGHT INTO EARLY MONDAY...NORTH OF THE INTERSTATE 80
CORRIDOR. THE GFS AND ECMWF KEEP MOST OF THE PRECIPITATION ALONG THE
COAST AND NORTH OF THE AREA. ALTHOUGH THE GEM BRINGS PRECIPITATION
OVER ALL OF INTERIOR NORTHERN CALIFORNIA. THE FORECAST LEANS MORE
TOWARDS THE GFS AND ECMWF WITH PRECIPITATION MAINLY IN THE COASTAL
RANGE AND SHASTA COUNTY. A RIDGE BUILDS IN BEHIND THIS SYSTEM
BREAKING A BREAK IN THE PRECIPITATION MONDAY NIGHT.
&&
.AVIATION...
WEAK SYSTEM WILL MOVE ACROSS NORTHERN CALIFORNIA THIS
EVENING...FOLLOWED BY A SECONDARY SYSTEM DIGGING DOWN THE COAST
TONIGHT AND TUESDAY. AS A RESULT...A FEW LIGHT SHOWERS WILL BE
POSSIBLE THIS EVENING...WITH AREAS OF MVFR CONDITIONS IN THE VALLEY
AND IFR CONDITIONS IN THE SIERRA. MORE WIDESPREAD SHOWERS WILL
DEVELOP BETWEEN 06Z AND 12Z AS THE SECONDARY SYSTEM DIGS SOUTH.
CEILINGS WILL ALSO LOWER...WITH WIDESPREAD MVFR AND AREAS OF IFR
CONDITIONS POSSIBLE IN THE VALLEY AND IFR/LIFR IN THE SURROUNDING
MOUNTAINS. SNOW LEVELS WILL ALSO LOWER TO BETWEEN 3500 AND 4000
FEET BY MORNING.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 082253
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
253 PM PST MON FEB 8 2010
.SYNOPSIS...
LOW CLOUDS AND FOG WILL PERSIST FOR MUCH OF TODAY AND TONIGHT
THROUGH THE SAN JOAQUIN VALLEY. THE NEXT FRONTAL SYSTEM WILL MOVE
THROUGH THE REGION TUESDAY NIGHT THROUGH WEDNESDAY PRODUCING RAIN
AND HIGHER ELEVATION SNOW.
&&
.DISCUSSION...AN INSIDE SLIDER IS TAKING SHAPE ALONG 130W OFF THE
OREG/NORCAL COAST. THIS WILL PUSH SE ALONG THE CA COAST TUES AND
TUES EVENING...REACHING SOCAL EARLY WED. THIS WILL BE A QUICK
MOVING SYSTEM...AND OVERALL DONT EXPECT MUCH PRECIP. THE EXCEPTION
COULD BE THE KERN MTNS WHERE CONDS WILL BE RIGHT FOR A GOOD SNOW
EVENT...ESPECIALLY THE TEHACHAPIS...AND IN PARTICULAR...THE FORT
TEJON/FRAZIER PARK AREA AS AN EASTERLY FLOW DEVELOPS STRONG
OROGRAPHICS ON THE SOUTH AND EAST FACING SLOPES. CUDDY VALLEY CAN
BE ESPECIALLY HARD HIT IN THESE TYPES OF EVENTS.
NO HEADLINES WILL BE ISSUED FOR THE SRN SIERRA...AS THIS WILL BE A
COASTAL HUGGER...WHICH RARELY RESULTS IN SIGNIFICANT PRECIP.
HOWEVER THERE COULD BE SEVERAL INCHES OF SNOW AT AND ABOVE 3500
FEET OR SO. COULD BE SOME MIXING OF PRECIP OR CHANGE OVER TO SNOW
AT TIMES IN THE HIGH DESERTS NEAR 2500 FEET OR SO. STILL VERY HARD
TO SAY IF ACCUMULATING SNOW WILL OCCUR ON THE DESERT FLOOR TUES
NITE...BUT CERTAINLY NEAR AND OVER THE FOOTHILLS.
ALSO...AS THE COLD POOL ALOFT SLIDES BY JUST TO THE WEST TUES
AFTERNOON...ENOUGH INSTABILITY COULD BE GENERATED TO PRODUCE AN
ISOLATED TSTM FROM THE VALLEY INTO THE TEHACHAPIS...AND EVEN
DESERTS. MAIN THREAT OF TSTMS WILL BE TO THE WEST OVER THE COAST
RANGES...BUT VALLEY SB CAPES REACH ABOUT 500 J/KG IN THE AFTERNOON
WITH LI/S NEAR ZERO.
THE SLIDER WILL MOVE QUICKLY EAST ALONG THE OLD MEX/ARIZ BORDER
WED. THIS WILL BRING AN ABRUPT END TO ALL BUT A FEW LINGERING
MTN/DESERT SHOWERS BY NOON WED...IF NOT SOONER.
FLAT RIDGING IS THEN FCST BY MOST MED RANGE MODELS TO LAST
BASICALLY THE REMAINDER OF THE FCST. WEAKENING SYSTEMS THAT
PREVIOUSLY HAD BEEN FCST BY MODELS TO DRAG SOME WEAK FRONTS ACROSS
CENTRAL CA LATER THIS WEEK AND EARLY NEXT...HAVE JUST ABOUT
EVAPORATED. HAVE GONE TO A DRY FCST BEYOND WEDNESDAY...EXCEPT FOR
SOME SMALL POPS FROM FRESNO NORTH THURS NITE-FRI. BUT WOULDNT BE
SURPRISED TO SEE THESE GO AWAY AS WELL.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...MAINLY VFR THROUGH 06Z TUESDAY...AREAS
OF MVFR IN BR FROM 06Z-12Z TUESDAY AND IN RAIN AFTER 12Z TUESDAY.
IN THE SIERRA NEVADA AND TEHACHAPI MOUNTAINS...MVFR AND LCL IFR CIGS
AND MOUNTAIN OBSCURATIONS THROUGH 06Z TUESDAY...THEN LOWERING
CEILINGS WITH -RA SPREADING IN FROM THE NORTH AFTER 08Z TUESDAY. IN
THE KERN COUNTY DESERT...VFR THROUGH 18Z TUESDAY.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
MORNING CAZ095.
&&
$$
PUBLIC...BINGHAM
AVN/FW...BEAN
SYNOPSIS...WP
WEATHER.GOV/HANFORD
000
FXUS66 KMTR 082236 CCA
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
230 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 2:30 PM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
MOUNT VACA RADAR IS ALREADY STARTING TO INDICATE PRECIPITATION OFF
THE SONOMA COAST THIS AFTERNOON AS A WEAK UPPER LEVEL TROUGH
MOVES ONSHORE FROM THE WEST. RAINFALL IS EXPECTED TO MOSTLY BE
LIGHT TONIGHT WITH TOTALS UNDER .2". THESE SHOWERS ARE AN EARLY
PREVIEW OF THE MAIN EVENT FOR TOMORROW WHEN A STRONG TROUGH AND LOW
CENTER DIVE SOUTHWARD ALONG THE COAST. MODEL GUIDANCE CONTINUES TO
SHOW INSTABILITY WITH THIS FEATURE AS LIFTED VALUES GO NEGATIVE...
SOME CAPE...AND 925 MB WINDS PICK UP TO 30 KT. TEMPERATURES WILL BE
THE MAIN STORY AS 700 MB LEVELS DROP TO BETWEEN -10 AND -12C WHICH
ROUGHLY TRANSLATES TO A SNOW LEVEL AROUND 3000 FEET. HOWEVER...
LEVELS COULD LOCALLY BE AS LOW AS 2000 FEET WITH THE HEAVIEST
SHOWERS. SMALL HAIL CAN ALSO BE EXPECTED. UNFORTUNATELY STILL LOOKS
LIKE THE STRONGEST OF THE SHOWERS WILL MOVE INTO THE BAY AREA CLOSE
TO THE MORNING RUSH. ALTHOUGH THERE IS STILL A LITTLE UNCERTAINTY
WITH THE TRACK OF THE LOW...THE OVERALL CONSENSUS WOULD BRING THE
BEST PRECIPITATION FIELD TO THE COASTAL MOUNTAINS SOUTH OF SAN
FRANCISCO WHERE UP TO AN 1" IS NOT OUT OF THE QUESTION. A WINTER
WEATHER ADVISORY HAS ALSO BEEN ISSUED FOR 2-3" OF SNOW FOR 2500-3000
FEET AND UP TO 7" FOR ELEVATIONS ABOVE 3000 FEET. BIGGEST QUESTION
MARK CENTERS AROUND THE EAST BAY/DIABLO AREA WHERE THE BULK OF THE
COLD AIR WILL NOT QUITE MAKE IT AND THE HEAVIER PRECIPITATION IS
EXPECTED TO REMAIN SOUTH OF. WITH PLENTY OF CLOUDS THROUGH THE DAY
AND COOL AIR ADVECTING IN...HIGHS TOMORROW WILL STRUGGLE TO GET INTO
THE 50S. WITH SOME CLEARING EXPECTED TUESDAY NIGHT...ESPECIALLY OVER
THE NORTH BAY...LOWS SHOULD DROP BACK INTO THE LOW 30S FOR THE
COOLEST SPOTS ALONG WITH PATCHY FROST.
AFTER A DRY DAY ON WEDNESDAY...A WEAK TROUGH MOVES ONSHORE FOR
THURSDAY WITH A SECOND STRONGER FEATURE ON FRIDAY. EARLY QPF NUMBERS
HAVE 2 DAY TOTALS MOSTLY UNDER 1/2" FOR ALL METRO AREAS WITH HIGHER
TOTALS EXPECTED THE FURTHER NORTH YOU TRAVEL. SNOWFALL IS NOT
EXPECTED FROM THIS SYSTEM.
DRY WEATHER STILL ON TAP FOR THE WEEKEND.
&&
.AVIATION...AS OF 10:25 AM MONDAY...HIGH PRESSURE OVER THE
FORECAST AREA THIS MORNING BUT PRESSURES ALOFT BEGINNING TO DROP
AHEAD OF NEXT INCOMING SHORT-WAVE TROF DUE TO ARRIVE AFTER DAWN
TUESDAY MORNING. RESIDUAL AND PERSISTENT LOW-LEVEL MOISTURE TO
MAINTAIN MVFR CIGS AROUND THE S.F.BAY AREA UNTIL 22Z. ELSEWHERE
MVFR CIG AROUND MONTEREY BAY SCATTERING OUT PRIOR TO 20Z. MID AND
HIGH CLOUDS WITH CIGS AT OR ABOVE 10K FT AFT 23Z. RETURN OF LOW-
LEVEL CLOUDS LATE EVENING AND MVFR CIGS AFTER MIDNIGHT AROUND THE
BAY AREA. EXPECT -RA BY 15Z TUESDAY MORNING. THE TROF TUESDAY
MORNING BRINGS VERY COLD AIR SO EXPECT FREEZING LEVELS TO DROP BY
MID-DAY TUESDAY TO AROUND 3000 FT MSL.
VICINITY OF KSFO...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 22Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS SW-W 10-15KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 15Z TUESDAY.
KSFO BRIDGE APPROACH...BRIDGE APPROACH MVFR BKN-OVC025-035 UNTIL
22Z. VSBYS UNRESTRICTED BELOW DECKS. MVFR WITH CIGS/VSBYS IN RAIN
BY 15Z TUESDAY.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 2030Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS W-WNW 5-10KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 16Z TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 082235
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
230 PM PST MON FEB 8 2010
.DISCUSSION...AS OF 2:30 AM PST MONDAY...SHOWERS THROUGH TUESDAY
WITH SNOW POSSIBLY DOWN TO 2000 FEET.
MOUNT VACA RADAR IS ALREADY STARTING TO INDICATE PRECIPITATION OFF
THE SONOMA COAST THIS AFTERNOON AS A WEAK UPPER LEVEL TROUGH
MOVES ONSHORE FROM THE WEST. RAINFALL IS EXPECTED TO MOSTLY BE
LIGHT TONIGHT WITH TOTALS UNDER .2". THESE SHOWERS ARE AN EARLY
PREVIEW OF THE MAIN EVENT FOR TOMORROW WHEN A STRONG TROUGH AND LOW
CENTER DIVE SOUTHWARD ALONG THE COAST. MODEL GUIDANCE CONTINUES TO
SHOW INSTABILITY WITH THIS FEATURE AS LIFTED VALUES GO NEGATIVE...
SOME CAPE...AND 925 MB WINDS PICK UP TO 30 KT. TEMPERATURES WILL BE
THE MAIN STORY AS 700 MB LEVELS DROP TO BETWEEN -10 AND -12C WHICH
ROUGHLY TRANSLATES TO A SNOW LEVEL AROUND 3000 FEET. HOWEVER...
LEVELS COULD LOCALLY BE AS LOW AS 2000 FEET WITH THE HEAVIEST
SHOWERS. SMALL HAIL CAN ALSO BE EXPECTED. UNFORTUNATELY STILL LOOKS
LIKE THE STRONGEST OF THE SHOWERS WILL MOVE INTO THE BAY AREA CLOSE
TO THE MORNING RUSH. ALTHOUGH THERE IS STILL A LITTLE UNCERTAINTY
WITH THE TRACK OF THE LOW...THE OVERALL CONSENSUS WOULD BRING THE
BEST PRECIPITATION FIELD TO THE COASTAL MOUNTAINS SOUTH OF SAN
FRANCISCO WHERE UP TO AN 1" IS NOT OUT OF THE QUESTION. A WINTER
WEATHER ADVISORY HAS ALSO BEEN ISSUED FOR 2-3" OF SNOW FOR 2500-3000
FEET AND UP TO 7" FOR ELEVATIONS ABOVE 3000 FEET. BIGGEST QUESTION
MARK CENTERS AROUND THE EAST BAY/DIABLO AREA WHERE THE BULK OF THE
COLD AIR WILL NOT QUITE MAKE IT AND THE HEAVIER PRECIPITATION IS
EXPECTED TO REMAIN SOUTH OF. WITH PLENTY OF CLOUDS THROUGH THE DAY
AND COOL AIR ADVECTING IN...HIGHS TOMORROW WILL STRUGGLE TO GET INTO
THE 50S. WITH SOME CLEARING EXPECTED TUESDAY NIGHT...ESPECIALLY OVER
THE NORTH BAY...LOWS SHOULD DROP BACK INTO THE LOW 30S FOR THE
COOLEST SPOTS ALONG WITH PATCHY FROST.
AFTER A DRY DAY ON WEDNESDAY...A WEAK TROUGH MOVES ONSHORE FOR
THURSDAY WITH A SECOND STRONGER FEATURE ON FRIDAY. EARLY QPF NUMBERS
HAVE 2 DAY TOTALS MOSTLY UNDER 1/2" FOR ALL METRO AREAS WITH HIGHER
TOTALS EXPECTED THE FURTHER NORTH YOU TRAVEL. SNOWFALL IS NOT
EXPECTED FROM THIS SYSTEM.
DRY WEATHER STILL ON TAP FOR THE WEEKEND.
&&
.AVIATION...AS OF 10:25 AM MONDAY...HIGH PRESSURE OVER THE
FORECAST AREA THIS MORNING BUT PRESSURES ALOFT BEGINNING TO DROP
AHEAD OF NEXT INCOMING SHORT-WAVE TROF DUE TO ARRIVE AFTER DAWN
TUESDAY MORNING. RESIDUAL AND PERSISTENT LOW-LEVEL MOISTURE TO
MAINTAIN MVFR CIGS AROUND THE S.F.BAY AREA UNTIL 22Z. ELSEWHERE
MVFR CIG AROUND MONTEREY BAY SCATTERING OUT PRIOR TO 20Z. MID AND
HIGH CLOUDS WITH CIGS AT OR ABOVE 10K FT AFT 23Z. RETURN OF LOW-
LEVEL CLOUDS LATE EVENING AND MVFR CIGS AFTER MIDNIGHT AROUND THE
BAY AREA. EXPECT -RA BY 15Z TUESDAY MORNING. THE TROF TUESDAY
MORNING BRINGS VERY COLD AIR SO EXPECT FREEZING LEVELS TO DROP BY
MID-DAY TUESDAY TO AROUND 3000 FT MSL.
VICINITY OF KSFO...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 22Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS SW-W 10-15KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 15Z TUESDAY.
KSFO BRIDGE APPROACH...BRIDGE APPROACH MVFR BKN-OVC025-035 UNTIL
22Z. VSBYS UNRESTRICTED BELOW DECKS. MVFR WITH CIGS/VSBYS IN RAIN
BY 15Z TUESDAY.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 2030Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS W-WNW 5-10KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 16Z TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WINTER WEATHER ADVISORY ABOVE 2500 FEET FOR
DIABLO RANGE...SANTA CRUZ MTNS...SANTA LUCIA
MTNS...AND SAN BENITO MTNS STARTING 6AM TUE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSGX 082235
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
233 PM PST MON FEB 8 2010
.SYNOPSIS...
A DEEPENING LOW PRESSURE SYSTEM MOVING SOUTH ALONG THE WEST COAST
TONIGHT...IS EXPECTED TO TURN EAST ON TUESDAY...MOVING ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY. WINTER STORM
WATCHES HAVE BEEN ISSUED FOR THE MOUNTAINS DUE TO THE POSSIBILTY OF
HEAVY SNOW. WINTER WEATHER ADVISORIES MAY BE ISSUED FOR TUESDAY
NIGHT AND WEDNESDAY TO INCLUDE THE HIGH DESERTS...FOOTHILLS...AND
INLAND VALLEYS. HAIL FROM THUNDERSTORMS WEDNESDAY MAY ALSO ICY
CONDITIONS FOR AREAS CLOSE TO THE COAST. WEAK HIGH PRESSURE WILL
REBUILD THURSDAY. A TROUGH MOVING INLAND TO THE NORTH ON FRIDAY MAY
BRING SOME LIGHT RAIN AND SNOW. WARMING AND DRYING IS FORECAST FOR
FOR THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY...
HIGH PRESSURE RIDGE ALOFT WILL CONTINUE THROUGH THE NIGHT. A VERY
COLD LOW IN THE VICINITY OF 45N 132W AT 1300 PST...WITH HEIGHTS OF
5350-5400 METERS AT 500 MB...CONTINUES TO DROP SOUTH SOUTHEASTWARD
ALONG THE WEST COAST AS FORECAST BY ALL MODELS. A TURN TOWARDS THE
EAST AS IT GETS OVER THE SOUTHERN CALIFORNIA BIGHT AND TRACKING
DIRECTLY ACROSS SOUTHWEST CALIFORNIA ALSO APPEARS LIKELY.
FAIRLY HIGH CONFIDENCE IN THIS FORECAST SOLUTION AS WELL AS WINTER
STORM CONDITIONS DEVELOPING. HAVE ISSUED THE WINTER STORM WATCH FOR
THE MOUNTAINS AND A SPECIAL WEATHER STATEMENT FOR THE REMAINDER OF
THE FORECAST ZONES WITH THE IDEA THAT THIS WILL BE LATER UPGRADED TO
A WINTER WEATHER ADVISORY. THE STRONG DIVERGENCE ALOFT IS STILL
SHOWN AND THIS RAISES THE QUESTION OF SEVERE THUNDERSTORM
DEVELOPMENT LATE TUESDAY NIGHT AND WEDNESDAY. FOR NOW HAVE INCLUDED
MENTION OF THUNDERSTORMS WITH SMALL HAIL FOR MOST ZONES AND ISOLATED
WATERSPOUTS OVER WATER. WRAP AROUND MOISTURE INTO WEDNESDAY EVENING.
CLEARING WEDNESDAY NIGHT INTO THURSDAY MORNING AND LINGERING COLD
AIR SHOULD ALLOW FROST FORMATION OVER LOWER DESERTS/VALLEYS.
SIGNIFICANTLY UNDERCUT MOS TEMPS FOR WEDNESDAY NIGHT/THURSDAY
MORNING. FOR THURSDAY WARMER AND GENERALLY CLEAR THOUGH MAY SEE
INCREASING CIRROSTRATUS TOWARDS THE END OF THURSDAY FROM LIFTING DUE
TO WARM AIR OVERRUNNING AHEAD OF NEXT TROUGH.
.LONG TERM...THURSDAY NIGHT INTO SUNDAY...
BOTH THE ECMWF AND GFS HAVE TRENDED TOWARDS WASHING OUT THE NEXT
TROUGH SOUTH OF POINT CONCEPTION FRIDAY/FRIDAY NIGHT. MODIFIED
CLOUDS/POPS/WEATHER GRIDS SLIGHTLY TO KEEP A SLIGHT CHANCE OF LIGHT
RAIN/SNOW FOR FRIDAY INTO FRIDAY EVENING. AFTER FRIDAY
EVENING...HIGH PRESSURE RIDGE REBUILDS AND WEEKEND LOOKS FAIRLY
NICE. ONLY SPOILER MIGHT BE A BACKDOOR COLD FRONT COMING ACROSS THE
MOJAVE DESERT LATE SATURDAY/SUNDAY FROM THE CLOSED LOW THAT IS
FORECAST TO DEVELOP AFTER THE TROUGH MOVES INLAND. CURRENTLY THIS
SCENARIO IS NOT INCLUDED IN THE EXTENDED FORECAST TEMPS.
&&
.AVIATION...
082000Z...SCATTERED STRATOCU WITH BASES AROUND FL030 SHOULD DIMINISH
AFTER SUNSET. A MOSTLY CLEAR SKY IS EXPECTED TONIGHT WITH SOME
RADIATIONAL FOG DEVELOPING NEAR SUNRISE IN THE USUAL LOCATIONS SUCH
AS KCNO...KAJO AND KRNM. EXPECT AN INCREASE IN MID AND HIGH CLOUDS
WITH BASES AT OR ABOVE FL150 TUESDAY AFTERNOON AND LOWER STRATOCU/CU
WITH BASES BETWEEN FL030 AND FL040 AHEAD OF THE NEXT STORM MOVING IN
FROM THE NORTHWEST. HORTON
&&
.HYDROLOGY...
BECAUSE OF THE EXTREMELY LOW FREEZING LEVELS...DROPPING TO 2000
FEET...THINKING THIS WILL BE A HEAVY SNOW EVENT RATHER THAN A HEAVY
RAIN EVENT. PRECIPITATION RATES HOWEVER COULD BE ONE INCH PER HOUR
OR HIGHER TUESDAY NIGHT INTO WEDNESDAY MORNING JUST AHEAD OF AND
ALONG THE COLD FRONT...AND BRIEFLY IN THUNDERSTORMS THAT DEVELOP ON
WEDNESDAY. QPF AMOUNTS WERE ADJUSTED SLIGHTLY TO SHOW MORE UPSLOPE
PRECIPITATION ALONG THE NORTH AND EAST SLOPES WEDNESDAY...OTHERWISE
NUMBERS ARE ABOUT THE SAME.
WATER EQUIVALENT QPF AMOUNTS ARE...
ORANGE COUNTY/SW SAN BERNARDINO COUNTY...0.50 TO 1.00 INCHES AT THE
COAST TO 1.5 TO 2.5 INCHES ON THE COASTAL SLOPES...AND 0.50 TO 1.00
INCHES HIGH DESERT AREAS....AND FOR
WESTERN RIVERSIDE/SAN DIEGO COUNTIES...0.50 TO 0.75 INCHES AT THE
COAST TO 1 TO 2 INCHES COASTAL SLOPES....AND 0.25 TO 0.50 INCHES
LOWER DESERTS.
SNOW FALL AMOUNTS...USED TEN TO ONE SNOW TO WATER RATIO THROUGH 10 PM
TUESDAY THEN SLOWLY RAISED IT ABOUT ONE INCH EVERY SIX HOURS
THEREAFTER.
IN THE SAN GABRIEL MOUNTAINS...THE SAN BERNARDINO MOUNTAINS...AND
THE SAN JACINTO MOUNTAINS...SNOWFALL AMOUNTS COASTAL SLOPES 8 TO 20
INCHES BETWEEN 3500 AND 6500 FEET AND OVER THREE FEET AT ELEVATIONS
ABOVE 7000 FEET. DESERT SLOPES...4 TO 8 INCHES.
IN THE SANTA ANA MOUNTAINS...THE SANTA ROSA MOUNTAINS...AND THE
MOUNTAINS IN SAN DIEGO COUNTY...SNOWFALL AMOUNTS COASTAL SLOPES 4 TO
8 INCHES BETWEEN 3500 AND 5000 FEET AND 8 AND 20 INCHES AT
ELEVATIONS ABOVE 5000 FEET. DESERT SLOPES 2 TO 6 INCHES.
FOR HIGH DESERT VALLEY FLOORS...COASTAL FOOTHILLS/INLAND
VALLEYS...LOWER DESERTS...BETWEEN 2000 AND 3500 ELEVATION...SNOW
AMOUNTS BETWEEN 1 AND 4 INCHES ARE FORECAST.
HAIL ACCUMULATIONS WEDNESDAY COULD ADD ANOTHER INCH OR TWO AT LOWER
ELEVATIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO
COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-SANTA ANA
MOUNTAINS AND FOOTHILLS.
PZ...NONE.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS65 KREV 082229
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
229 PM PST MON FEB 8 2010
.SHORT TERM - / TONIGHT THROUGH THURSDAY / ...
MAIN ISSUE FOR THE NEXT 24-30 HOURS IS THE COLD LOW DROPPING SOUTH
ALONG THE CALIFORNIA COAST. TRACK OF THE LOW WILL KEEP MOST OF
THE SHOWERS WEST OF THE SIERRA. HOWEVER AN INCREASE IN
MOISTURE...INSTABILITY AND A LOW TO MID LEVEL EASTERLY FLOW WILL
BRING SHOWERS TO THE SIERRA AND WESTERN NEVADA THROUGH TUESDAY
NIGHT.
MID-UPPER LEVEL MOISTURE AND DIFLUENT FLOW ALOFT AHEAD OF THE
SYSTEM WILL BRING SHOWERS TO THE NORTHERN SIERRA AND NORTHWEST
NEVADA AS EARLY AS THIS EVENING. SNOW LEVELS WILL DROP TO VALLEY
FLOORS BY EARLY TUESDAY MORNING...SO MOST OF THE SHOWER ACTIVITY
WILL BE SNOW.
THE BEST INSTABILITY DOES NOT REACH THE RENO-TAHOE AREA UNTIL
TUESDAY MORNING. WITH THE CONVECTIVE NATURE OF THE EVENT...IT IS
DIFFICULT TO PLACE WHERE SHOWERS/SNOW BANDS WILL BE HEAVIEST. DO
NOT EXPECT WIDESPREAD SNOW ACCUMULATIONS IN THE RENO-CARSON
AREA...SO IMPACTS TO THE MORNING COMMUTE ARE MINIMAL AT THIS
TIME. HOWEVER LOCATIONS AFFECTED BY SNOW SHOWERS COULD RECEIVE AN
INCH OR TWO OF SNOW IN A SHORT PERIOD OF TIME.
CONCERNS INCREASE TUESDAY AFTERNOON AND TUESDAY EVENING AS SEVERAL
FACTORS COINCIDE. A BIT OF SURFACE WARMING WILL INCREASE
INSTABILITY AS MOISTURE WRAPS AROUND THE LOW AND THE COLDEST AIR
ALOFT PASSES OVER THE EASTERN SIERRA. MODELS DROP THE LIFTED
INDEX TO -1...WITH 100-200 J/KG OF CAPE THROUGH THE MOIST UNSTABLE
LAYER OVER THE EASTERN SIERRA AND FAR WESTERN NEVADA. BY THIS
TIME THE LOW IS SOUTH OF MONTEREY BAY...TURNING THE LOW AND MID
LEVEL FLOW TO THE EAST-NORTHEAST. THIS PRODUCES A FAVORABLE
ENVIRONMENT FOR AN UPSLOPE EVENT ALONG THE EAST SLOPES SOUTH OF
US-50. LOCATIONS THAT COULD RECEIVE A FEW HOURS OF LIGHT TO MODERATE
SNOW ARE...DOUGLAS...SOUTHERN LYON...WESTERN MINERAL...ALPINE AND
MONO COUNTIES. DEPENDING ON THE LENGTH OF THE UPSLOPE EVENT
AMOUNTS UP TO 6 INCHES ARE POSSIBLE...ESPECIALLY FOR ALPINE AND
MONO COUNTIES.
SHORT WAVE RIDGE PASSES OVER THE AREA WEDNESDAY INTO EARLY
THURSDAY FOR DRIER CONDITIONS. HIGHS WEDNESDAY SHOULD WARM SEVERAL
DEGREES WITH RIDGE AXIS OVER WESTERN NEVADA AND A LIGHT SOUTH TO
SOUTHWEST SURFACE FLOW. CLOUDS WILL INCREASE THURSDAY NORTH OF
US-50 AS THE NEXT PACIFIC WAVE NEARS THE COAST. LIGHT WARM AIR
ADVECTION RAIN/SNOW IS POSSIBLE FOR LASSEN AND NORTHERN WASHOE
COUNTIES THURSDAY AFTERNOON. BRONG
.LONG TERM (THURSDAY NIGHT - MONDAY)...
BASED ON THE 5-DAY MEAN 500MB HEIGHTS FROM GFS/EC, OVERALL PATTERN
DURING THE LONG TERM IS CHARACTERIZED BY A STRONG JET OVER THE
CENTRAL PACIFIC WITH DOWNSTREAM DIRTY RIDGE OVER WRN NOAM.
OCCASIONAL WEAK SYSTEMS WILL STILL AFFECT THE REGION, BUT NOTHING
MAJOR. TELECONNECTIONS WITH NEGATIVE ANOMALY OVER CNTRL ALEUTIANS
SUGGEST SLIGHTLY ABV NORMAL PRECIP IN NRN SIERRA. CONFIDENCE LEVELS
IN THE LONG TERM RANGE FROM HIGH (4/5) EARLY IN THE PERIOD TO
LOW/MODERATE (2/5) BY MONDAY...AS NCEP RMOP PRODUCTS SHOW A LOW
PREDICTABILITY PATTERN DEVELOPING BY EARLY NEXT WEEK WITH NO MAJOR
ANOMALIES TO LATCH ONTO.
WEAK UPPER TROF EXPECTED TO MOVE INTO THE REGION THURS NGT INTO
FRIDAY, WITH DIFFERENCES IN LATITUDINAL POSN OF THE LOW. MUCH OF THE
PRECIP WOULD LIKELY FALL THURS NGT IN THE SIERRA, MAINLY N OF TVL
PER GEFS. SPILLOVER UNCERTAIN THOUGH RELATIVELY DEEP MOISTURE WOULD
SUGGEST AT LEAST A FEW SHOWERS INTO WRN NV. EXPECTING SNOW LEVELS TO
FALL TO ROUGHLY 5000-5500 FT BASED ON SOUNDINGS AND 700MB TEMPS.
RIDGING FCST TO OVERSPREAD THE AREA SAT/SUN WITH RAPIDLY WARMING
TEMPS, ESPECIALLY AT RIDGE TOP LEVELS. SHOULD BE A RELATIVELY
TRANQUIL WEEKEND WITH GOOD TRAVEL CONDITIONS. EC AND GFS BRING A
WEAKER SYSTEM INTO THE REGION MON. QPF VALUES ARE QUITE LOW AND GEFS
POPS ARE ALMOST NON-EXISTENT. WOULD BE INCLINED TO DECREASE ONGOING
CHC POPS, HOWEVER LOWER PREDICTABILITY ENVIRONMENT AND TIMING
DIFFERENCES PRECLUDE MAKING CHANGES AT THIS TIME.
CS
&&
.AVIATION...
COLD UNSTABLE SYSTEM FCST TO DROP INTO CA/NV TUESDAY AND TUESDAY
NIGHT. PRIMARY AVIATION IMPACT WILL BE FROM SNOW AND REDUCED
CIGS/VSBYS. WINDS ARE NOT A CONCERN. PRECIP WILL BE MORE SHOWERY
WITH THE UNSTABLE ATMOSPHERE, THEREFORE IT WILL BE HARD TO PREDICT
EXACT TIMING OF LOWER CIGS/VSBYS MORE THAN A FEW HOURS OUT. ALSO,
SLIGHT CHANGES IN THE PATH OF THE UPPER LOW WILL HAVE A BIG IMPACT
ON PRECIP COVERAGE OVER THE SIERRA AND WRN NV.
THEREFORE CONFIDENCE IN THE TAFS TODAY IS ONLY MODERATE (3/5) AND I
HAVE KEPT THEM RATHER GENERAL WITH NO TEMPO GROUPS. LIKELIHOOD OF
SEEING PERIODS OF LIFR CONDS IN +SHSN IS ABOUT 25% AT RNO AND 70% AT
TVL/TRK BETWEEN ROUGHLY 09Z/09 AND 00Z/10. SNOW MAY IMPACT THE
TUESDAY MORNING DEPARTURES OUT OF RNO.
CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KLOX 082205
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PST MON FEB 8 2010
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW...AS WELL AS
A SLIGHT CHANCE OF THUNDERSTORMS...TO THE AREA TUESDAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOLER TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK...WITH THE EXCEPTION OF SOME LIGHT SHOWERS
POSSIBLE ON FRIDAY.
&&
.SHORT TERM (TODAY-THU)...
A COLD UPPER LEVEL LOW PRESSURE SYSTEM OFF THE PACIFIC NORTHWEST COAST
IS EXPECTED TO TRACK RAPIDLY SOUTHWARD OVERNIGHT...AND BECOME
CENTERED OFF THE COAST OF MONTEREY BY 18Z TUESDAY. MODELS HAVE BEEN
TRENDING FASTER WITH THIS SYSTEM...SO HAVE BUMPED UP POPS A BIT
DURING THE DAY TUESDAY. SHOWERS WILL BECOME LIKELY ACROSS THE CENTRAL
COAST TUESDAY MORNING...THEN ARE EXPECTED TO BECOME WIDESPREAD
ACROSS THE FORECAST AREA ON TUESDAY AFTERNOON. DURING THIS TIME...
MODEL CROSS SECTIONS SHOW DEEPENING MOISTURE AND INCREASING DYANMICS
ACROSS THE REGION.
THERE IS ALSO RAPID COLD AIR ADVECTION ALOFT...WITH VERY IMPRESSIVE
500 MB TEMPERATURES OF -32 DEGREES AT THE CORE OF THE UPPER LOW
CENTER! THIS COLD CORE LOW PRESSURE CENTER IS EXPECTED TO TRACK
RIGHT OVER THE FORECAST AREA TUESDAY NIGHT. AS THE COLDER AIR
FILTERS INTO THE AREA...LOOK FOR INCREASING INSTABILITY WITH
LIFTED INDEX VALUES OF 0 TO -2. THIS TYPE OF PATTERN CERTAINLY
LOOKS CONDUCIVE TO THUNDERSTORM DEVELOPMENT...WITH LOTS OF SMALL
HAIL REPORTS LIKELY. WITH FAIRLY IMPRESSIVE DYANMICS AND SUCH
COLD AIR ALOFT...NOT OUT OF THE QUESTION THAT SOME HAIL COULD APPROACH
SEVERE LIMITS. IN ADDITION TO HAIL...ANY THUNDERSTORM THAT DEVELOPS
WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS AND BRIEF HEAVY
DOWNPOURS. DUE TO THE CYCLONIC FLOW ALOFT AND UNSTABLE AIR MASS...
THERE WILL ALSO BE THE POTENTIAL FOR WATERSPOUTS OVER THE COASTAL
WATERS...WHICH HAS BEEN HIGHLIGHTED IN A MARINE WEATHER STATEMENT.
THE BULK OF THE SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TUESDAY
AFTERNOON INTO TUESDAY EVENING...WITH SHOWERS LIKELY REMAINING ACROSS
LOS ANGELES COUNTY OVERNIGHT TUESDAY NIGHT. BY WEDNESDAY
MORNING...ALL MODELS AGREE ON DROPPING THE CLOSED LOW SOUTH AND EAST
OF FORECAST AREA...WITH WRAP AROUND MOISTURE CONTINUING THE THREAT
OF SHOWERS WELL INTO THE DAY WEDNESDAY ACROSS THE MOUNTAINS OF
LA/VTU COUNTIES AS WELL AS THE ANTELOPE VALLEY.
RAINFALL AMOUNTS ARE GENERALLY EXPECTED TO RANGE BETWEEN .50 AND 1.00
INCHES ACROSS COASTAL AND VALLEY AREAS...WITH UP TO 1.50 INCHES
POSSIBLE IN THE FOOTHILLS AND LOWER COASTAL SLOPES. DUE TO THE SHOWERY
NATURE OF THE PRECIPITATION...RAINFALL AMOUNTS ARE EXPECTED TO BE
QUITE VARIABLE. IT IS ALSO IMPORTANT TO REMEMBER THAT HIGHER
RAINFALL AMOUNTS CAN BE EXPECTED FOR THOSE AREAS UNDER
THUNDERSTORMS. AT THIS TIME...IT APPEARS THAT LOS ANGELES COUNTY
WILL LIKELY RECEIVE THE HIGHEST RAINFALL AMOUNTS...ESPECIALLY ACROSS
EASTERN SECTIONS...DUE TO THE BEST CYCLONIC FLOW PATTERN FOR THAT
AREA. THERE WILL BE THE POTENTIAL FOR HEAVIER SHOWERS AND
THUNDERSTORMS ACROSS THE RECENT BURN AREAS...ESPECIALLY LOS ANGELES
COUNTY. FOR THE STATION FIRE...THE BEST CHANCE FOR THE HEAVIER
SHOWERS IS EXPECTED TO OCCUR FROM MID AFTERNOON THROUGH EVENING ON
TUESDAY. RAINFALL RATES ARE GENERALLY EXPECTED TO BE LESS THAN .25
INCHES PER HOUR...BUT WE COULD SEE RATES LOCALLY AS HIGH AS .50
INCHES PER HOUR NEAR HEAVIER SHOWERS OR THUNDERSTORMS. LATER SHIFTS
MAY NEED TO ISSUE A FLASH FLOOD WATCH FOR THE RECENT BURN AREAS OF
LOS ANGELES COUNTY...ESPECIALLY IF THIS SYSTEM TAKES ON A MORE
OVER-WATER TRAJECTORY.
A MAJOR IMPACT OF THIS UPCOMING STORM WILL BE THE VERY LOW SNOW
LEVELS. INITALLY...SNOW LEVELS ARE EXPECTED TO RANGE BETWEEN 3500
AND 4000 FEET TUESDAY...THEN LOWER QUICKLY TO AROUND 3000 FEET
ACROSS THE NORTHERN MOUNTAINS ON TUESDAY AFTERNOON AS THE COLDER AIR
SPILLS INTO THE REGION. THICKNESS VALUES BOTTOM OUT AT A VERY
IMPRESSIVE 530 DM OVERNIGHT ON TUESDAY NIGHT! AS A RESULT...LOOK FOR
SNOW LEVELS TO FALL TO BETWEEN 2000 AND 2500 FEET TUESDAY
NIGHT...POSSIBLY EVEN LOWER UNDER ANY THUNDERSTORMS. WRAP AROUND
MOISTURE WILL LIKELY BRING THE THREAT OF ADDITIONAL SHOWERS TO THE
MOUNTAINS (ESPECIALLY NORTH FACING SLOPES) AND ANTELOPE VALLEY
THROUGH MUCH OF THE DAY WEDNESDAY. WINTER STORM WATCHES WILL BE
POSTED FOR THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS...WHERE 6 TO
12 INCHES OF SNOW IS EXPECTED...WITH LOCAL AMOUNTS UP TO 16 INCHES
POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE SAN GABRIELS. DUE TO
THE LOW SNOW LEVELS EXPECTED...MAJOR LOW ELEVATION TRAFFIC CORRIDORS
WILL LIKELY BE IMPACTED BY ACCUMULATING SNOW...INCLUDING INTERSTATE
5 NORTH OF CASTAIC AS WELL AS HIGHWAY 14 THROUGH THE SOLEDAD CANYON.
WINTER WEATHER ADVISORIES HAVE ALSO BEEN POSTED FOR THE MOUNTAINS OF
SLO/SBA COUNTIES...WHERE 3 TO 6 INCHES OF SNOW CAN BE EXPECTED.
THE UNUSUAL LOW SNOW LEVELS WILL LIKELY BRING ACCUMULATING SNOW TO
SUCH PLACES AS THE ANTELOPE VALLEY...CUYAMA VALLEY...INTERIOR VALLEYS
OF SLO COUNTY...AS WELL AS THE HIGHER PEAKS OF THE SANTA MONICA
MOUNTAINS. THESE AREAS MAY REQUIRE WINTER WEATHER ADVISORIES AS WE
DRAW CLOSER TO THE EVENT...FOR NOW JUST HIGHLIGHTED IN A SPECIAL
WEATHER STATEMENT. THIS SYSTEM HAS THE POTENTIAL TO BRING BRIEF SNOW
SHOWERS TO UNUSUAL LOCATIONS ACROSS THE SOUTHLAND TUESDAY
NIGHT...SUCH AS SOME OF THE FOOTHILL LOCATIONS IN LOS ANGELES AND
VENTURA COUNTIES. THE ATMOSPHERE WILL DRY OUT AND BEGIN TO MODIFY
ON THURSDAY.
.LONG TERM (FRI-MON)...
ANOTHER WEAK SYSTEM WILL BRING A CHANCE OF SHOWERS ON FRIDAY...MAINLY
NORTH OF POINT CONCEPTION. HOWEVER...MODELS HAVE BEEN CONTINUING TO
TREND DRIER WITH THIS SYSTEM WITH TIME. THEN DRY WEATHER IS EXPECTED
THROUGH THE REMAINDER OF THE WEEKEND WITH NEAR SEASONAL NORMALS
EXPECTED.
&&
.AVIATION...08/1930Z.
GOOD CONFIDENCE IN VFR TO LOCAL MVFR CONDITIONS LASTING AT MOST OR
ALL TAF SITES THROUGH TONIGHT. SOME OF THE COASTAL AND VALLEY TAF
SITES ARE CONTENDING WITH LOW CLOUDS THIS MORNING. ANOTHER STORM
SYSTEM WILL DESCEND UPON THE REGION ON TUESDAY...LEADING TO MVFR TO
ISOLATED IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION.
KLAX AND KBUR...VFR TO MVFR CONDITIONS WILL DETERIORATE TO MVFR TO
LOCAL IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION BY TUESDAY WITH
THE ADVANCE OF A COLD STORM SYSTEM.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...SWEET
SYNOPSIS...MEIER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 082155 AAB
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 PM MST MON FEB 8 2010
.UPDATE...ANOTHER UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
MOSTLY CLEAR SKIES WITH BELOW NORMAL TEMPERATURES WILL OCCUR TODAY.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE NORTHWEST AND
BRING INCREASING CLOUDINESS ON TUESDAY. AS THIS LOW MOVES THROUGH...
EXPECT A CHANCE FOR RAIN AND MOUNTAIN SNOW SHOWERS...AS WELL AS A
SLIGHT CHANCE FOR A THUNDERSTORM...MAINLY OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER LATE TUESDAY NIGHT AND EARLY
WEDNESDAY...AND OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA WEDNESDAY
AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL THURSDAY AS THE
LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY
CONDITIONS WITH SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY
THROUGH THE UPCOMING WEEKEND.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES OBSERVED OVER THE LOWER DESERT THIS MORNING...
WITH SOME RATHER FLAT CUMULIFORM CLOUD DEVELOPMENT LIMITED TO
EASTERN GILA COUNTY. WEAK SUBSIDENCE FORECAST OVER REGION IN WAKE OF
TROF PASSAGE LAST NIGHT...SO MOSTLY SUNNY SKY CONDITION EXPECTED
OVER THE LOWER DESERT TODAY...WITH JUST SCT STRATOCUMULUS CLOUDS.
EVEN WITH PLENTY OF SUNSHINE...MAX TEMPS WILL BE 6-8 DEGREES BELOW
NORMAL AT MOST SITES TODAY...GIVEN OBSERVED BOUNDARY LAYER TEMPS.
FORECAST HIGH FOR PHOENIX...63 DEGREES...IS 7 DEGREES BELOW NORMAL
FOR THE DATE.
NEXT WEATHER SYSTEM TO AFFECT OUR FORECAST AREA IS CURRENTLY WEST OF
THE WASHINGTON-OREGON COAST. MORNING NUMERICAL MODELS IN EXCELLENT
AGREEMENT REGARDING EVOLUTION/TRACK OF THIS AREA OF LOW PRESSURE...
WITH 500 MB REFLECTION OF THE LOW NEAR SAN DIEGO BY 12Z
WEDNESDAY...AND NEAR ORGAN PIPE NM BY 00Z THURSDAY.
FROM PREVIOUS DISCUSSION...NEXT SHORT WAVE TROUGH...CURRENTLY
APPROACHING THE PAC NW COAST...WILL IMPACT OUR CWA BEGINNING LATE
TUESDAY AND CONTINUING THROUGH EARLY THURSDAY. OPERATIONAL AND
ENSEMBLE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND
INTENSITY OF THIS LOW THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A
STRONG H25 SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY
ROUGHLY STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST-NOT EXACTLY OPTIMAL FOR INGESTING MOIST AIR
FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE INTO
OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP WITH
LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT OF THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX AND KIWA...
LOW LEVEL MOISTURE IS SLOW TO DECREASE...IN FACT KSDL WENT OVC FOR
AWHILE THIS AFTN. BUT AS WEAK UPPER RIDGE AND STABLE AIRMASS LINGERS
OVERHEAD...OUR CLOUDS WILL PERSIST INTO THE EVENING HOURS. SCT/BKN
SC NOW EXPECTED WITH BASES NEAR 6-8 THSD FT. INCREASING MID/HIGH
CLOUDS FOR TUESDAY ASSOCIATED WITH NEXT PAC SYSTEM. LGT DIURNAL
WINDS THRU AT LEAST 09/1200Z.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY SOME INCREASING MID AND HI CLOUDS TONIGHT AND TUESDAY AS NEXT
PAC SYSTEM DEVELOPS FURTHER. GENERALLY LGT WINDS THRU AT LEAST
09/1200Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
000
FXUS66 KEKA 082134
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
134 PM PST MON FEB 8 2010
.SYNOPSIS...A WEAK DISTURBANCE WILL BRING RAIN AND HIGHER ELEVATION
SNOW TO THE AREA TONIGHT INTO TUESDAY. MORE PRECIPITATION IS
EXPECTED ON THURSDAY AS ANOTHER FRONT PUSHES ASHORE.
&&
.DISCUSSION...A VERY DISTINCT LOW AS SEEN ON WATER VAPOR IMAGERY
CURRENTLY NEAR 43N 132W WILL SCOOT DOWN THE CA COASTLINE OVER THE
NEXT 36 HRS. A FEW ECHOES ARE CURRENTLY SHOWING UP ON RADAR NW OF
CRESCENT CITY...BUT THESE ARE MOST LIKELY LOWER CLOUDS WELL AHEAD
OF THE MAIN SYSTEM. THE BULK OF THE RAIN IS EXPECTED TO DEVELOP
THIS EVENING AND SPREAD SOUTH OVERNIGHT. CONVECTION IS STILL
POSSIBLE OVER THE WATER AS LAPSE RATES STEEPEN WITH THE APPROACH
OF THE COLD UPPER LOW. SNOW LEVELS WILL BE TRICKY TO DETERMINE
OVERNIGHT AS INTERIOR VALLEY LOCATIONS ARE STARTING OFF COLD. FREE
AIR SNOW LEVELS WILL DROP TO AROUND 2500 FT TONIGHT...WITH SNOW
POTENTIALLY FALLING EVEN LOWER. QPF VALUES LOOK TO REMAIN
GENERALLY UNDER 0.30 INCHES...SO SNOW ACCUMULATIONS SHOULD REMAIN
AOB 4 INCHES BELOW THE 4000 FT PASS LEVEL.
SUBSIDENCE BEHIND THIS FEATURE SHOULD DRY UP THE PRECIPITATION
QUICKLY FROM NORTH TO SOUTH TUE AFTERNOON...WITH CLEARING SKIES
NOT FAR BEHIND. THIS SCENARIO MAY LEAD TO FOG FORMATION ON WED
MORNING. SHORTWAVE RIDGING SHOULD KEEP US DRY ON WED...WITH THE
NEXT SYSTEM POISED TO DROP MORE RAIN ON US AS EARLY AS WED NIGHT.
THE MAIN FRONTAL BOUNDARY DOESN`T MOVE THROUGH UNTIL THU/THU
NIGHT...WHICH SHOULD BRING HEAVIER RAIN COMPARED TONIGHTS SYSTEM.
MODELS ARE TRENDING DRIER FOR THE WEEKEND AS A RIDGE BUILDS
ACROSS THE INTER-MOUNTAIN WEST...THUS THE BIGGEST FCST CHANGE WAS
TO DECREASE PRECIP CHANCES DURING THAT PERIOD. JCA
&&
.MARINE...MODERATE WNW SWELL WILL CONTINUE THROUGH WEDNESDAY. WINDS
WILL REMAIN LIGHT N/NW TONIGHT THEN INCREASE TUESDAY/TUESDAY NIGHT
BEHIND A COLD FRONT. ANOTHER APPROACHING COLD FRONT WILL LIKELY
RESULT IN GALES FORCE WINDS OR GUSTS FOR THURSDAY...THEN FOLLOWED BY
THE A LARGE ASSOCIATED SWELL FOR FRIDAY/SATURDAY. THIS SWELL LOOKS
TO PEAK AROUND 18 FT. HENRY
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS
EVENING. A COLD FRONT WILL DROP SOUTH LATE TONIGHT AND EARLY
TUESDAY. MVFR CONDITIONS WITH RAIN ARE EXPECTED TO ACCOMPANY THIS
FRONT AS IT MOVES THROUGH THE AREA. HENRY
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KLOX 081932
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1130 AM PST MON FEB 8 2010
NEW AVIATION DISCUSSION
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW AS WELL AS A
SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA TUESDAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOLER TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK...WITH THE EXCEPTION OF SOME LIGHT SHOWERS
POSSIBLE ACROSS THE CENTRAL COAST ON FRIDAY.
&&
.SHORT TERM (TODAY-WED)...
SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES THIS MORNING EXCEPT
CONTINUED MOSTLY CLOUDY SKIES CONTINUING OVER THE NORTH SLOPES
AND INTERIOR VALLEYS OF SLO/SBA COUNTIES. THESE CLOUDS SHOULD
DIMINISH BY EARLY AFTERNOON. THERE COULD BE A SPRINKLE OR A FLURRY
WITH THESE CLOUDS OVER THE NORTH SLOPES. TODAY WILL BE PARTLY CLOUDY
AND COOL.
GENERAL FORECAST FOR TUESDAY AND EARLY WEDNESDAY REMAINS ON TRACK.
A COLD UPPER LOW WILL PINCH OFF FROM ITS PARENT PAC NW TROF AND WORK
ITS WAY DOWN THE COAST. IT WILL BRING A CHANCE OF SHOWERS TO THE
CENTRAL COAST BY TUESDAY MORNING. LATEST 12Z NAM/GFS GUIDANCE SHOW
THAT SHOWERS WILL LIKELY SPREAD ACROSS MUCH OF THE FORECAST AREA
BY TUESDAY AFTERNOON...SO WILL BE BUMPING UP POPS TO LIKELY IN ALL
AREAS DURING THAT TIME FRAME. OTHER UPCOMING CHANGE WILL BE LOWERING
OF SNOW LEVELS. PER COORDINATION WITH SAN DIEGO OFFICE...WILL HAVE
SNOW LEVELS BETWEEN 3500 AND 4000 FEET TUESDAY AFTERNOON...LOWERING
TO AS LOW AS 2000 FEET LATE TUESDAY NIGHT. WINTER STORM WATCH WILL
BE POSTED WITH AFTERNOON PACKAGE FOR LA/VTU COUNTY MOUNTAINS. AND
WILL HIGHLIGHT OTHER LOW SNOW LEVEL IMPACTS FOR OTHER AREAS IN
UPCOMING SPECIAL WEATHER STATEMENT. THE LOW SNOW LEVELS COULD BRING
SIGNIFICANT IMPACT TO MAJOR TRAFFIC CORRIDOR SUCH AS INTERSTATE 5
NORTH OF CASTAIC AS WELL AS HIGHWAY 14 THROUGH SOLEDAD CANYON.
*** FROM PREVIOUS DISCUSSION ***
RAINFALL AMOUNTS WITH THIS SYSTEM WILL BE TRICKY. THE CURRENT
FORECAST CALLS FOR 0.50" TO 1.00" ACROSS COASTAL/VALLEY AREAS WITH
UP TO 1.50" IN THE MOUNTAINS. UNFORTUNATELY THE AMOUNT OF RAINFALL
IS GREATLY DEPENDENT ON THE TRACK OF THE STORM. THE CURRENT TRACK IS
ABOUT HALF OVER LAND HALF OVER WATER. IF THE STORM TRACKS MORE
EASTWARD THERE WILL BE LESS RAIN AND IF IT MOVE WESTWARD MORE OVER
THE WATER IT WILL BE WETTER. WITH THUNDERSTORMS NOW IN THE MIX THERE
WILL BE A FEW AREAS THAT GET MORE RAINFALL AND WITH GREATER RATES
THAN THE OVERALL STORM SYSTEM. EXCEPT FOR THE SMALL POSSIBILITY OF
A DIRECT TSTM HIT...THE BURN AREAS SHOULD NOT BE TOO THREATENED BY
THIS SYSTEM.
.LONG TERM (THU-SUN)...
GFS AND EC IN QUITE GOOD AGREEMENT FOR THE LONG TERM. THURSDAY WILL
BE UNEVENTFUL WITH A COOLISH 570DM RIDGE OVERHEAD. A WEAK FRONT WILL
ROLL THROUGH THE AREA FRIDAY. IT WILL CLOUD THINGS UP BUT WILL ONLY
BRING A CHC OF RAIN TO THE AREA NORTH OF POINT CONCEPTION AND JUST A
SLIGHT CHC SOUTH. RIDGING PUSHES INTO THE AREA SATURDAY AND LASTS
INTO SUNDAY. SKIES WILL BE...AT WORST...PARTLY CLOUDY. TEMPS WILL
RISE SOME BUT HGTS WILL ONLY BE AROUND 573 DM AND NOW THE OFFSHORE
FLOW DOES NOT LOOK AS STRONG AS IT DID YDY SO DO NOT LOOK FOR A BIG
WARM UP.
&&
.AVIATION...08/1930Z.
GOOD CONFIDENCE IN VFR TO LOCAL MVFR CONDITIONS LASTING AT MOST OR
ALL TAF SITES THROUGH TONIGHT. SOME OF THE COASTAL AND VALLEY TAF
SITES ARE CONTENDING WITH LOW CLOUDS THIS MORNING. ANOTHER STORM
SYSTEM WILL DESCEND UPON THE REGION ON TUESDAY...LEADING TO MVFR TO
ISOLATED IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION.
KLAX AND KBUR...VFR TO MVFR CONDITIONS WILL DETERIORATE TO MVFR TO
LOCAL IFR CONDITIONS DUE TO CLOUDS AND PRECIPITATION BY TUESDAY WITH
THE ADVANCE OF A COLD STORM SYSTEM.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...SWEET
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 081844
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1025 AM PST MON FEB 8 2010
UPDATED FOR AVIATION DISCUSSION...
.DISCUSSION...AS OF 8:50 AM PST MONDAY...SHOWERS RETURN ON TUESDAY
WITH SNOW LEVELS EXPECTED DOWN AS LOW AS 2000 FEET. ANOTHER CHANCE
FOR RAIN LATE THURSDAY INTO FRIDAY.
VISIBLE SATELLITE IMAGE SHOWS CLOUDS ACROSS A GOOD PORTION OF THE
CWA THIS MORNING. TEMPERATURES STARTED OUT GENERALLY IN THE 40S
ALTHOUGH A FEW MID 30S WERE REPORTED IN NORTH BAY VALLEYS. WITH
PLENTY OF LOW LEVEL MOISTURE IN PLACE AND A WEAK ONSHORE/WESTERLY
GRADIENT AT THE SURFACE...CLOUDS WILL BE SLOW TO BURN OFF AND WILL
LIKELY KEEP TEMPERATURES FROM WARMING UP MUCH ABOVE THE MID 50S.
SHOWERS WILL RETURN TO THE AREA OVERNIGHT TONIGHT AS A COLD SYSTEM
DROPS DOWN FROM THE NNW. MODEL GUIDANCE HAD VARIED GREATLY WITH THE
TRACK OF THIS FEATURE BUT IS FINALLY SETTLING ON A SOLUTION WHICH
BRINGS THE TROUGH AXIS PARALLEL TO THE COAST AND THE UPPER LEVEL
LOW WEST OF POINT REYES EARLY TUESDAY MORNING. THE LOW WILL THEN
MOVE JUST TO THE WEST OF MONTEREY BAY BY EARLY TUESDAY AFTERNOON AND
CONTINUE TO THE SOUTH INTO WEDNESDAY. AS THE LOW TRACKS TO THE
SOUTH...MOISTURE WRAPPING AROUND IT WILL ROTATE INTO OUR CWA AND
SPREAD FROM THE COAST TO INLAND SPOTS. LATEST FORECAST SOUNDINGS
CONTINUE TO SHOW SOME INSTABILITY ALONG WITH FREEZING LEVELS AROUND
3000 FEET AND VERY LOW CONVECTIVE TEMPERATURES. THEREFORE...WILL KEEP
A MENTION OF THUNDER AND SMALL HAIL IN THE FORECAST. DESPITE THE 3000
FOOT FREEZING LEVEL...ANY STRONG CELLS COULD EASILY DUMP SNOW DOWN TO
THE 2000 FOOT MARK. TIMING BRINGS PRECIP TO SF CLOSE TO THE MORNING
RUSH WITH EAST BAY/SANTA CLARA LOOKING MORE LIKE A LATE MORNING
START. PRECIP TOTALS HAVE BE UPPED A BIT AS THE TRACK OF THE LOW IS
FAVORABLE FOR HIGHER AMOUNTS PARTICULARLY FOR SAN MATEO SOUTHWARD.
FINAL TOTALS SHOULD BE LESS THAN 1/4" FOR MAIN METRO AREAS WITH UP TO
1/2" FOR HIGHER ELEVATIONS...IN PARTICULAR THE SANTA CRUZ AND SANTA
LUCIA MOUNTAINS. SNOW ADVISORY CRITERIA ONLY REQUIRE 2" IN 12 HOURS
FOR SPOTS UNDER 3000 FEET AND FOR THOSE TWO AREAS THAT SEEMS LIKELY
TO HAPPEN. 4-7" IS NECESSARY ABOVE 3000 FEET AND CONSIDERING THE
FREEZING LEVEL WILL BE THAT LOW...IT CERTAINLY SEEMS POSSIBLE. WILL
LIKELY ISSUE A SNOW ADVISORY WITH THE AFTERNOON PACKAGE. FINALLY...
BASED ON THE TRACK...THIS DOES NOT LOOK FAVORABLE FOR SNOWFALL OVER
THE NORTH BAY HILLS. 50-50 CALL NEAR THE DIABLO RANGE. THE SYSTEM
WILL EXIT TUESDAY NIGHT.
AFTER A DRY DAY ON WEDNESDAY AND MUCH OF THURSDAY...ANOTHER TROUGH
WILL MOVE TO THE COAST THURSDAY NIGHT. THIS PROGRESSIVE FEATURE
WILL PUSH RAIN WEST TO EAST ACROSS THE CWA. UNLIKE THE
CONVECTIVE SYSTEM ON TUESDAY...700 MB TEMPS ONLY DROP TO AROUND MINUS
3 WHILE LIFTED VALUES REMAIN POSITIVE. RAINFALL AMOUNTS WILL
GENERALLY BE UNDER 1/3" WITH COASTAL MOUNTAINS LOOKING FOR UP TO AN
INCH AT THE MOST. DRY WEATHER IS STILL EXPECTED FOR THE WEEKEND.
&&
.AVIATION...AS OF 10:25 AM MONDAY...HIGH PRESSURE OVER THE
FORECAST AREA THIS MORNING BUT PRESSURES ALOFT BEGINNING TO DROP
AHEAD OF NEXT INCOMING SHORT-WAVE TROF DUE TO ARRIVE AFTER DAWN
TUESDAY MORNING. RESIDUAL AND PERSISTENT LOW-LEVEL MOISTURE TO
MAINTAIN MVFR CIGS AROUND THE S.F.BAY AREA UNTIL 22Z. ELSEWHERE
MVFR CIG AROUND MONTEREY BAY SCATTERING OUT PRIOR TO 20Z. MID AND
HIGH CLOUDS WITH CIGS AT OR ABOVE 10K FT AFT 23Z. RETURN OF LOW-
LEVEL CLOUDS LATE EVENING AND MVFR CIGS AFTER MIDNIGHT AROUND THE
BAY AREA. EXPECT -RA BY 15Z TUESDAY MORNING. THE TROF TUESDAY
MORNING BRINGS VERY COLD AIR SO EXPECT FREEZING LEVELS TO DROP BY
MID-DAY TUESDAY TO AROUND 3000 FT MSL.
VICINITY OF KSFO...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 22Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS SW-W 10-15KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 15Z TUESDAY.
KSFO BRIDGE APPROACH...BRIDGE APPROACH MVFR BKN-OVC025-035 UNTIL
22Z. VSBYS UNRESTRICTED BELOW DECKS. MVFR WITH CIGS/VSBYS IN RAIN
BY 15Z TUESDAY.
MRY BAY AREA TERMINALS...MVFR CIGS025-035 BECOMING VFR SCT035-045
BY 2030Z. VSBYS ESSENTIALLY UNRESTRICTED BELOW DECKS. SURFACE
WINDS W-WNW 5-10KTS. MVFR WITH CIGS/VSBYS IN RAIN BY 16Z TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 081811 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1110 AM MST MON FEB 8 2010
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
MOSTLY CLEAR SKIES WITH BELOW NORMAL TEMPERATURES WILL OCCUR TODAY.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE NORTHWEST AND
BRING INCREASING CLOUDINESS ON TUESDAY. AS THIS LOW MOVES THROUGH...
EXPECT A CHANCE FOR RAIN AND MOUNTAIN SNOW SHOWERS...AS WELL AS A
SLIGHT CHANCE FOR A THUNDERSTORM...MAINLY OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER LATE TUESDAY NIGHT AND EARLY
WEDNESDAY...AND OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA WEDNESDAY
AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL THURSDAY AS THE
LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY
CONDITIONS WITH SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY
THROUGH THE UPCOMING WEEKEND.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES OBSERVED OVER THE LOWER DESERT THIS MORNING...
WITH SOME RATHER FLAT CUMULIFORM CLOUD DEVELOPMENT LIMITED TO
EASTERN GILA COUNTY. WEAK SUBSIDENCE FORECAST OVER REGION IN WAKE OF
TROF PASSAGE LAST NIGHT...SO MOSTLY SUNNY SKY CONDITION EXPECTED
OVER THE LOWER DESERT TODAY...WITH JUST SCT STRATOCUMULUS CLOUDS.
EVEN WITH PLENTY OF SUNSHINE...MAX TEMPS WILL BE 6-8 DEGREES BELOW
NORMAL AT MOST SITES TODAY...GIVEN OBSERVED BOUNDARY LAYER TEMPS.
FORECAST HIGH FOR PHOENIX...63 DEGREES...IS 7 DEGREES BELOW NORMAL
FOR THE DATE.
NEXT WEATHER SYSTEM TO AFFECT OUR FORECAST AREA IS CURRENTLY WEST OF
THE WASHINGTON-OREGON COAST. MORNING NUMERICAL MODELS IN EXCELLENT
AGREEMENT REGARDING EVOLUTION/TRACK OF THIS AREA OF LOW PRESSURE...
WITH 500 MB REFLECTION OF THE LOW NEAR SAN DIEGO BY 12Z
WEDNESDAY...AND NEAR ORGAN PIPE NM BY 00Z THURSDAY.
FROM PREVIOUS DISCUSSION...NEXT SHORT WAVE TROUGH...CURRENTLY
APPROACHING THE PAC NW COAST...WILL IMPACT OUR CWA BEGINNING LATE
TUESDAY AND CONTINUING THROUGH EARLY THURSDAY. OPERATIONAL AND
ENSEMBLE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND
INTENSITY OF THIS LOW THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A
STRONG H25 SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY
ROUGHLY STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST-NOT EXACTLY OPTIMAL FOR INGESTING MOIST AIR
FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE INTO
OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP WITH
LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT OF THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX AND KIWA...
LOW LEVEL MOISTURE IS SLOW TO DECREASE...AS WEAK UPPER RIDGE PUSHES
EASTWARD. FEW/SCT SC CLOUDS BELOW 8 THSD FT STILL IN FORECASTS...TIL
AROUND 01Z. MAINLY SKC AFT DARK. INCREASING MID/HIGH CLOUDS STILL
EXPECTED ON TUESDAY ASSOCIATED WITH NEXT PAC SYSTEM. LGT DIURNAL
WINDS THRU AT LEAST 09/1200Z.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY SOME INCREASING MID AND HI CLOUDS TONIGHT AND TUESDAY AS NEXT
PAC SYSTEM DEVELOPS FURTHER. GENERALLY LGT WINDS THRU AT LEAST
09/1200Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...SIPPLE
FIRE WEATHER...ELLIS
000
FXUS65 KREV 081743
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
943 AM PST MON FEB 8 2010
.UPDATE...
ISOLATED SHOWERS CONTINUE TO AFFECT THE RENO-SPARKS AREA THIS
MORNING...SO ADDED THEM TO THE FORECAST. 12Z SOUNDINGS SHOWS A
SHALLOW MOIST AND UNSTABLE LAYER UP TO 700 MB. MODELS ONLY DEPICT
MINIMAL DRYING AHEAD OF THE APPROACHING LOW THIS AFTERNOON...SO
SOME HEATING AND A 36F CONVECTIVE TEMPERATURE SHOULD ALLOW A FEW
SHOWERS TO CONTINUE THIS AFTERNOON. ALSO LOWERED HIGH TEMPERATURE A
COUPLE DEGREES FOR THE AMOUNT OF CLOUD COVER. BRONG
&&
.PREVIOUS DISCUSSION... /ISSUED 320 AM PST MON FEB 8 2010/
SHORT TERM...
ABUNDANT LOW LEVEL MOISTURE HANGING AROUND THE WESTERN GREAT
BASIN THIS MORNING IN THE WAKE OF A DEPARTING UPPER LOW. SHORTWAVE
RIDGING WILL CONTINUE TO BUILD OVERHEAD...WITH WINDS ALOFT DROPPING
OFF. FOG FORECAST THIS MORNING IS LOOKING LESS LIKELY...DUE TO THE
LINGERING CLOUDS NOT ALLOWING THE SURFACE TO COOL OFF. SOME OF
THE CLOUDS BEGINNING TO BREAK UP EAST OF RENO...BUT FREEZING FOG
HAS NOT DEVELOPED YET. WITH A FEW MORE HOURS OF DARKNESS THIS
MORNING...SOME PATCHY FOG MAY DEVELOP IN THE BASIN VALLEYS EAST
OF RENO.
A QUICK MOVING COLD LOW WILL SLIDE DOWN THE PACIFIC COAST
TUESDAY...BRINGING THE NEXT ROUND OF SNOW TO THE AREA. THIS STORM
WILL BE COLD...WITH SNOW LEVELS DOWN TO VALLEY FLOORS. LATEST
MODEL RUNS ARE IN MUCH BETTER AGREEMENT...WITH THE LOW PRESSURE
TRACKING DIRECTLY ALONG THE CALIFORNIA COAST. AS THE LOW TRACKS
ALONG WESTERN CA...DEFORMATION ZONE PRECIP WILL SETUP ALONG THE
EASTERN EDGE OF THE UPPER LOW. NAM-GFS ARE HINTING THAT THIS AREA
OF ENHANCED PRECIP WILL SETUP OVER EASTERN CA AND WESTERN
NV...BRINGING SNOW ACCUMULATIONS DOWN TO THE VALLEY FLOORS
TUESDAY. 00Z ECMWF ALSO TRACKS THE LOW PRESSURE OVER COASTAL CA AS
WELL...BUT KEEPS THE DEFORMATION ZONE PRECIP ALONG THE SIERRA
CREST AND WESTERN SLOPES. TRACK OF THE UPPER WILL BE EXTREMELY
IMPORTANT TO THE AMOUNT OF QPF/SNOW AMOUNTS THAT WE SEE IN OUR
AREA.
NORMALLY WITH AN INSIDE SLIDER...WOULD PREFER TO SEE THE UPPER
LOW TRACK FURTHER INLAND OVER THE COASTAL RANGES OF NORCAL OR EVEN
OVER THE CENTRAL VALLEY...SO THAT THE DEFORMATION ZONE SETS UP
OVER WESTERN NEVADA. BUT WITH NAM-GFS CONTINUING TO SHOW IMPRESSIVE
FRONTOGENESIS AND 6-12 HOURS OF STRONG DENDRITIC ZONE OMEGA/LIFT
OVER RENO-TAHOE ROUGHLY BETWEEN 4AM TO 4PM...WILL CONTINUE WITH
THE SNOWY FORECAST. WITH EACH PASSING MODEL RUN...CONFIDENCE
CONTINUES TO INCREASE WITH REGARD TO QPF VALUES EAST OF THE SIERRA.
INCREASED POPS/QPF FOR THE SIERRA ZONES TUES-TUES NIGHT. WENT AHEAD
WITH CATEGORICAL SNOW FOR MOST OF THE SIERRA AND INTO RENO-CARSON
ZONE WEST OF HIGHWAY 395. AS FOR SNOW AMOUNTS...UP TO A COUPLE
INCHES ARE POSSIBLE IN THE WESTERN NV VALLEYS TUESDAY...INCLUDING
RENO-CARSON CITY-MINDEN...WITH 2 TO 4 INCHES IN THE FOOTHILLS
WEST OF HIGHWAY 395. FOR THE EASTERN SIERRA AMOUNTS FROM 3 TO 6
INCHES FROM WESTERN LASSEN DOWN THROUGH TAHOE AND MONO COUNTY...UP
TO 8 INCHES ALONG THE CREST. IF THE FORECAST CONTINUES ON THIS
TRACK...MAY NEED WINTER STATEMENTS LATER TODAY. HOON
LONG TERM...THURSDAY THROUGH SUNDAY...
THERE IS A BIT MORE CONFIDENCE IN MODEL SOLNS THIS WEEKEND AS THE
ECMWF HAS COME CLOSER IN LINE WITH THE GFS/GEFS/GEM WHICH SHOW TROF
THU NGT-FRI FOLLOWED BY RIDGING THIS WEEKEND. ONE DIFFERENCE THAT
REMAINS IS HOW FAST TO PUSH THE FRI SYST EWD AS THE GFS IS MORE
CLOSED WITH FEATURE AND SLOWER THAN THE ECMWF TO ADVANCE IT EWD. THE
DETERMINISTIC ECMWF IS AT THE FAST SIDE OF THE ENVELOPE OF SOLNS AND
THUS THE FCST WAS KEPT CLOSER TO THE SLOWER GFS. HIGHEST POPS THU
NGT-FRI WERE TAPERED FROM N-S FRI NGT AND THEN DRIED OUT SAT-SUN AS
THERE IS NOW GOOD CONSENSUS FOR RDG. TEMPS NR OR SLGTLY BELOW NORMAL
THU-FRI ARE EXPECTED TO WARM SOME OVR THE WEEKEND ALTHOUGH PERIODS
OF MID-HI CLOUDS MAY MITIGATE THE POTENTIAL A BIT. HOHMANN
AVIATION...
FZFG BECOMING LESS A POTENTIAL THIS MRNG AS EXTENSIVE CLOUD COVER
HAS BEEN SLOW TO BREAK. LATEST SATELLITE PICTURES DID SHOW THINNING
AND EROSION OF THIS CLOUD DECK BUT IT WL NOT BE IN TIME TO ALLOW FOR
FOG DEVELOPMENT AT KRNO. LIFR CLOUD DECK HAS DEVELOPED AT KTRK WHERE
CLOUDS WERE THINNING ON WEST END AND THIS MAY LOWER FURTHER DURING
THE MRNG. SO WL CONT TO MENTION FZFG FOR KTRK AND KEEP IT THRU ABOUT
17Z. VFR ALL AREAS THIS AFTN/EVENING. NEXT SYST WL DROP DOWN THE W
COAST BEGINNING TNGT AND CONTG TUE WITH INCRG SNOW SHOWERS AND A
RETURN TO CIG/VSBY RESTRICTIONS INCLUDING MT OBSCUREMENT. CONDS WL
DETERIORATE 06Z-12Z AT KTVL/KTRK SITES WITH OCNL MVFR FLGT RULES IN
SNOW SHOWERS TUE AT KRNO AND WRN NV VLYS. ACCUMULATING SNOW IS
LIKELY AT SIERRA TAF SITES BUT UNLIKELY AT KRNO DUE TO TIMING OF
STORM DURING DAYLIGHT HOURS AND LIGHTER NATURE OF SNOW SHOWERS EAST
OF THE SIERRA. IF ONE OF THE MORE ISOLD HEAVIER BANDS MOVES ACRS THE
KRNO TERMINAL THEN SOME ACCUMULATION WOULD BE POSSIBLE BUT
SHORTLIVED. HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSTO 081729
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 AM PST MON FEB 8 2010
.DISCUSSION...
WEAKENED UPPER RIDGE OVER NORCAL THIS MORNING WITH SOME HIGH CLOUDS
OVERRUNNING INTO THE INTERIOR. THE HIGH CLOUDS HAVE HINDERED FOG
DEVELOPMENT IN THE NORTHERN SAC VALLEY. FARTHER SOUTH...PERSISTENT
STRATO-CU DECK OVER THE EASTERN HALF OF THE VALLEY EXPANDED WESTWARD
THIS MORNING AND IS THE AREA OF MAIN CONDENSATION. WEAK FRONT AND
ELONGATING UPPER TROUGH APPROACHING THE COAST WILL SLOWLY MOVE
INLAND TODAY INTO THIS EVENING BRINGING A SLIGHT CHANCE OF SOME
LIGHT PRECIP...MAINLY TO THE MOUNTAINS. ABUNDANT CLOUD COVER WILL
KEEP HIGHS THIS AFTERNOON GENERALLY IN THE 50S FOR THE CENTRAL
VALLEY WITH UPPER 30S TO 40S FOR THE MOUNTAINS.
100+ KT JET ALONG WESTERN SIDE OF UPSTREAM UPPER LOW AND TROUGH IN
GOA IS DIGGING SYSTEM TO THE SOUTHEAST. MODELS SIMILAR IN DEVELOPING
A SECONDARY LOW AND MOVING IT TO NEAR THE NW CALIFORNIA COAST BY
TUESDAY MORNING. LOW THEN PROGGED TO TRACK SOUTHWARD ALONG THE COAST
TOMORROW. ASSOCIATED SHOWERS POSSIBLE IN THE NORTHERN AND COASTAL
MOUNTAINS LATE TONIGHT AND OVER THE ENTIRE CWA TUESDAY. LIMITED
MOISTURE WITH THIS SYSTEM AS BLENDED TPW SHOWING PWS AROUND .75
INCHES OR LESS. MAIN COLD CORE ALOFT REMAINS MOSTLY WEST OF THE AREA
AS THE LOW MOVES DOWN THE COAST TUESDAY AND AS A RESULT...OVERALL
QPF AMOUNTS LOOK FAIRLY LIGHT. HOWEVER WITH CONVECTIVE NATURE OF THE
SYSTEM...POTENTIAL FOR SOME LOCALLY HEAVIER SHOWERS AND A SLIGHT
CHANCE OF A THUNDERSTORM OVER WESTERN PORTIONS OF THE VALLEY. QPF IN
THE MOUNTAINS LOOK FAIRLY LIGHT HOWEVER 12Z NAM BUFKIT PROFILE FOR
KBLU HAS TRENDED UP FROM 06Z RUN WITH ABOUT .6 INCHES FOR THE EVENT
WHICH IS SIMILAR TO 06Z GFS. WILL LOOK INTO POSSIBILITY OF LOW END
WINTER WEATHER ADVISORY FOR THE HIGHER SIERRA TERRAIN WITH THE
AFTERNOON PACKAGE. FLY IN OINTMENT THOUGH IS AS THE UPPER LOW TRACKS
SOUTHWARD ALONG THE COAST TUESDAY FLOW OVER THE SIERRA TURNS
DOWNSLOPE LIMITING PRECIP. SNOW LEVELS SHOULD DIP DOWN TO AROUND
3000 FEET TONIGHT AND RISE TO 4000 TO 5000 FEET TUESDAY AFTERNOON.
DECREASING CLOUDS TUESDAY NIGHT AS UPPER LOW TRACKS SOUTH OF THE
AREA AND SHORT WAVE RIDGING INCREASES SUBSIDENCE OVER NORCAL.
CLEARING SKIES WITH COLDER AMS WILL ALLOW GOOD RADIATIONAL COOLING
WITH MID TO UPPER 30S FOR THE CENTRAL VALLEY AND TEENS TO 20S IN THE
HIGH COUNTRY.
DRIER WEATHER MODELED OVER INTERIOR NORCAL WEDNESDAY INTO THURSDAY
AS UPPER RIDGE THE DOMINANT FEATURE HOWEVER SOME OVERRUNNING WARM
FRONTAL PRECIP POSSIBLE THURSDAY OVER THE COASTAL AND FAR NORTHERN
INTERIOR. POTENTIAL FOR SOME NIGHT AND MORNING VALLEY FOG INCREASES
DURING THIS PERIOD.
PCH
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
MODELS ARE IN GOOD AGREEMENT IN MOVING AN OPEN WAVE ACROSS INTERIOR
NORCAL ON FRI BRINGING A CHANCE OF PRECIP TO THE AREA. QPFS ARE
FORECAST TO BE HEAVIER ALONG THE COAST...BUT LIGHTER OVER THE
INTERIOR OF NORCAL...GENERALLY MORE IN THE .10 TO .30 INCH RANGE...A
WEAK TO MODEST SYSTEM AT BEST. THE OPEN WAVE IS FORECAST TO MOVE
INTO THE DESERT SW ALLOWING A POSITIVELY TILTED RIDGE TO BUILD OVER
NORCAL FOR THE WEEKEND...AND AHEAD OF A DEVELOPING GULF OF AK/ERN
PAC LONGER WAVE TROF. WE HAVE GONE WITH A DRY FORECAST FOR THE
WEEKEND AS ANY WAA PCPN IS EXPECTED TO STAY N AND W OF INTERIOR
NORCAL. THIS WILL BE A SEASONABLY MILD PATTERN WITH NEAR NORMAL
TEMPS AROUND 60 IN THE VALLEY...ALBEIT VALLEY STRATUS/FOG IS STILL A
MORNING CONCERN. THE AFOREMENTIONED DEVELOPING TROF IS FORECAST TO
MOVE INLAND SUN NITE AND MON WITH THE NEXT CHANCE OF PCPN. JHM
&&
.AVIATION...
WEAK FRONT WILL MOVE THROUGH TODAY WITH VFR/MVFR CONDITIONS EXPECTED
EXCEPT FOR ISOLD IFR/LIFR CONDITIONS WITH PATCHY FOG IN THE VALLEY
UNTIL 18Z THIS THIS MORNING. THE STRATOCUMULUS CLOUDS AROUND 4000 TO
5000 FEET IN THE VALLEY FROM AROUND KCIC SOUTH TO AROUND SACRAMENTO
AND DOWN INTO THE NORTHERN SAN JOAQUIN VALLEY MAY ERODE THIS
AFTERNOON AS THE CYCLONIC FLOW SHIFTS EAST WITH THE WEAK FRONT
APPROACHING AND MOVING THROUGH THE AREA. A STRONGER SYSTEM IS
CURRENTLY NEAR 43 N 133 W AND WILL APPROACH NORTHERN CALIFORNIA
TONIGHT BRINGING WIDESPREAD MVFR CONDITIONS AND LOCAL IFR CONDITIONS
ALONG WITH SHOWERS MAINLY AFTER 06Z. THIS SYSTEM IS EXPECTED TO MOVE
DOWN THE CALIFORNIA COAST ON TUESDAY FOR MORE SHOWERS AND POSSIBLY
ISOLATED THUNDERSTORMS AROUND SACRAMENTO AND SOUTH.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPSR 081729 CCA
AFDPSR
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 AM MST MON FEB 8 2010
.SYNOPSIS...
MOSTLY CLEAR SKIES WITH BELOW NORMAL TEMPERATURES WILL OCCUR TODAY.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE NORTHWEST AND
BRING INCREASING CLOUDINESS ON TUESDAY. AS THIS LOW MOVES THROUGH...
EXPECT A CHANCE FOR RAIN AND MOUNTAIN SNOW SHOWERS...AS WELL AS A
SLIGHT CHANCE FOR A THUNDERSTORM...MAINLY OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER LATE TUESDAY NIGHT AND EARLY
WEDNESDAY...AND OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA WEDNESDAY
AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL THURSDAY AS THE
LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY
CONDITIONS WITH SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY
THROUGH THE UPCOMING WEEKEND.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES OBSERVED OVER THE LOWER DESERT THIS MORNING...
WITH SOME RATHER FLAT CUMULIFORM CLOUD DEVELOPMENT LIMITED TO
EASTERN GILA COUNTY. WEAK SUBSIDENCE FORECAST OVER REGION IN WAKE OF
TROF PASSAGE LAST NIGHT...SO MOSTLY SUNNY SKY CONDITION EXPECTED
OVER THE LOWER DESERT TODAY...WITH JUST SCTD STRATOCUMULUS CLOUDS.
EVEN WITH PLENTY OF SUNSHINE...MAX TEMPS WILL BE 6-8 DEGREES BELOW
NORMAL AT MOST SITES TODAY...GIVEN OBSERVED BOUNDARY LAYER TEMPS.
FORECAST HIGH FOR PHOENIX...63 DEGREES...IS 7 DEGREES BELOW NORMAL
FOR THE DATE.
NEXT WEATHER SYSTEM TO AFFECT OUR FORECAST AREA IS CURRENTLY WEST OF
THE WASHINGTON-OREGON COAST. MORNING NUMERICAL MODELS IN EXCELLENT
AGREEMENT REGARDING EVOLUTION/TRACK OF THIS AREA OF LOW PRESSURE...
WITH 500 MB REFLECTION OF THE LOW NEAR SAN DIEGO BY 12Z
WEDNESDAY...AND NEAR ORGAN PIPE NM BY 00Z THURSDAY.
FROM PREVIOUS DISCUSSION...NEXT SHORT WAVE TROUGH...CURRENTLY
APPROACHING THE PAC NW COAST...WILL IMPACT OUR CWA BEGINNING LATE
TUESDAY AND CONTINUING THROUGH EARLY THURSDAY. OPERATIONAL AND
ENSEMBLE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND
INTENSITY OF THIS LOW THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A
STRONG H25 SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY
ROUGHLY STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST-NOT EXACTLY OPTIMAL FOR INGESTING MOIST AIR
FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE INTO
OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP WITH
LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT OF THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
KPHX...KIWA...KIPL...AND KBLH...
TYPICAL LIGHT DIURNAL WINDS ARE EXPECTED TODAY AND TONIGHT WITH A
FEW OR SCATTERED STRATOCUMULUS CLOUDS BETWEEN 5 AND 7 THOUSAND FEET.
INCREASING HIGH CIRRIFORM CLOUDINESS IS EXPECTED LATE TONIGHT AFTER
ABOUT 0800 GMT TUESDAY MORNING WELL AHEAD OF A PACIFIC STORM SYSTEM.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KSTO 081729
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 AM PST MON FEB 8 2010
.DISCUSSION...
WEAKENED UPPER RIDGE OVER NORCAL THIS MORNING WITH SOME HIGH CLOUDS
OVERRUNNING INTO THE INTERIOR. THE HIGH CLOUDS HAVE HINDERED FOG
DEVELOPMENT IN THE NORTHERN SAC VALLEY. FARTHER SOUTH...PERSISTENT
STRATO-CU DECK OVER THE EASTERN HALF OF THE VALLEY EXPANDED WESTWARD
THIS MORNING AND IS THE AREA OF MAIN CONDENSATION. WEAK FRONT AND
ELONGATING UPPER TROUGH APPROACHING THE COAST WILL SLOWLY MOVE
INLAND TODAY INTO THIS EVENING BRINGING A SLIGHT CHANCE OF SOME
LIGHT PRECIP...MAINLY TO THE MOUNTAINS. ABUNDANT CLOUD COVER WILL
KEEP HIGHS THIS AFTERNOON GENERALLY IN THE 50S FOR THE CENTRAL
VALLEY WITH UPPER 30S TO 40S FOR THE MOUNTAINS.
100+ KT JET ALONG WESTERN SIDE OF UPSTREAM UPPER LOW AND TROUGH IN
GOA IS DIGGING SYSTEM TO THE SOUTHEAST. MODELS SIMILAR IN DEVELOPING
A SECONDARY LOW AND MOVING IT TO NEAR THE NW CALIFORNIA COAST BY
TUESDAY MORNING. LOW THEN PROGGED TO TRACK SOUTHWARD ALONG THE COAST
TOMORROW. ASSOCIATED SHOWERS POSSIBLE IN THE NORTHERN AND COASTAL
MOUNTAINS LATE TONIGHT AND OVER THE ENTIRE CWA TUESDAY. LIMITED
MOISTURE WITH THIS SYSTEM AS BLENDED TPW SHOWING PWS AROUND .75
INCHES OR LESS. MAIN COLD CORE ALOFT REMAINS MOSTLY WEST OF THE AREA
AS THE LOW MOVES DOWN THE COAST TUESDAY AND AS A RESULT...OVERALL
QPF AMOUNTS LOOK FAIRLY LIGHT. HOWEVER WITH CONVECTIVE NATURE OF THE
SYSTEM...POTENTIAL FOR SOME LOCALLY HEAVIER SHOWERS AND A SLIGHT
CHANCE OF A THUNDERSTORM OVER WESTERN PORTIONS OF THE VALLEY. QPF IN
THE MOUNTAINS LOOK FAIRLY LIGHT HOWEVER 12Z NAM BUFKIT PROFILE FOR
KBLU HAS TRENDED UP FROM 06Z RUN WITH ABOUT .6 INCHES FOR THE EVENT
WHICH IS SIMILAR TO 06Z GFS. WILL LOOK INTO POSSIBILITY OF LOW END
WINTER WEATHER ADVISORY FOR THE HIGHER SIERRA TERRAIN WITH THE
AFTERNOON PACKAGE. FLY IN OINTMENT THOUGH IS AS THE UPPER LOW TRACKS
SOUTHWARD ALONG THE COAST TUESDAY FLOW OVER THE SIERRA TURNS
DOWNSLOPE LIMITING PRECIP. SNOW LEVELS SHOULD DIP DOWN TO AROUND
3000 FEET TONIGHT AND RISE TO 4000 TO 5000 FEET TUESDAY AFTERNOON.
DECREASING CLOUDS TUESDAY NIGHT AS UPPER LOW TRACKS SOUTH OF THE
AREA AND SHORT WAVE RIDGING INCREASES SUBSIDENCE OVER NORCAL.
CLEARING SKIES WITH COLDER AMS WILL ALLOW GOOD RADIATIONAL COOLING
WITH MID TO UPPER 30S FOR THE CENTRAL VALLEY AND TEENS TO 20S IN THE
HIGH COUNTRY.
DRIER WEATHER MODELED OVER INTERIOR NORCAL WEDNESDAY INTO THURSDAY
AS UPPER RIDGE THE DOMINANT FEATURE HOWEVER SOME OVERRUNNING WARM
FRONTAL PRECIP POSSIBLE THURSDAY OVER THE COASTAL AND FAR NORTHERN
INTERIOR. POTENTIAL FOR SOME NIGHT AND MORNING VALLEY FOG INCREASES
DURING THIS PERIOD.
PCH
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
MODELS ARE IN GOOD AGREEMENT IN MOVING AN OPEN WAVE ACROSS INTERIOR
NORCAL ON FRI BRINGING A CHANCE OF PRECIP TO THE AREA. QPFS ARE
FORECAST TO BE HEAVIER ALONG THE COAST...BUT LIGHTER OVER THE
INTERIOR OF NORCAL...GENERALLY MORE IN THE .10 TO .30 INCH RANGE...A
WEAK TO MODEST SYSTEM AT BEST. THE OPEN WAVE IS FORECAST TO MOVE
INTO THE DESERT SW ALLOWING A POSITIVELY TILTED RIDGE TO BUILD OVER
NORCAL FOR THE WEEKEND...AND AHEAD OF A DEVELOPING GULF OF AK/ERN
PAC LONGER WAVE TROF. WE HAVE GONE WITH A DRY FORECAST FOR THE
WEEKEND AS ANY WAA PCPN IS EXPECTED TO STAY N AND W OF INTERIOR
NORCAL. THIS WILL BE A SEASONABLY MILD PATTERN WITH NEAR NORMAL
TEMPS AROUND 60 IN THE VALLEY...ALBEIT VALLEY STRATUS/FOG IS STILL A
MORNING CONCERN. THE AFOREMENTIONED DEVELOPING TROF IS FORECAST TO
MOVE INLAND SUN NITE AND MON WITH THE NEXT CHANCE OF PCPN. JHM
&&
.AVIATION...
WEAK FRONT WILL MOVE THROUGH TODAY WITH VFR/MVFR CONDITIONS EXPECTED
EXCEPT FOR ISOLD IFR/LIFR CONDITIONS WITH PATCHY FOG IN THE VALLEY
UNTIL 18Z THIS THIS MORNING. THE STRATOCUMULUS CLOUDS AROUND 4000 TO
5000 FEET IN THE VALLEY FROM AROUND KCIC SOUTH TO AROUND SACRAMENTO
AND DOWN INTO THE NORTHERN SAN JOAQUIN VALLEY MAY ERODE THIS
AFTERNOON AS THE CYCLONIC FLOW SHIFTS EAST WITH THE WEAK FRONT
APPROACHING AND MOVING THROUGH THE AREA. A STRONGER SYSTEM IS
CURRENTLY NEAR 43 N 133 W AND WILL APPROACH NORTHERN CALIFORNIA
TONIGHT BRINGING WIDESPREAD MVFR CONDITIONS AND LOCAL IFR CONDITIONS
ALONG WITH SHOWERS MAINLY AFTER 06Z. THIS SYSTEM IS EXPECTED TO MOVE
DOWN THE CALIFORNIA COAST ON TUESDAY FOR MORE SHOWERS AND POSSIBLY
ISOLATED THUNDERSTORMS AROUND SACRAMENTO AND SOUTH.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPSR 081729 CCA
AFDPSR
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 AM MST MON FEB 8 2010
.SYNOPSIS...
MOSTLY CLEAR SKIES WITH BELOW NORMAL TEMPERATURES WILL OCCUR TODAY.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE NORTHWEST AND
BRING INCREASING CLOUDINESS ON TUESDAY. AS THIS LOW MOVES THROUGH...
EXPECT A CHANCE FOR RAIN AND MOUNTAIN SNOW SHOWERS...AS WELL AS A
SLIGHT CHANCE FOR A THUNDERSTORM...MAINLY OVER FAR SOUTHEAST
CALIFORNIA AND THE LOWER COLORADO RIVER LATE TUESDAY NIGHT AND EARLY
WEDNESDAY...AND OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA WEDNESDAY
AND WEDNESDAY EVENING. DRIER CONDITIONS WILL PREVAIL THURSDAY AS THE
LOW MOVES OFF TO OUR EAST...THOUGH IT WILL REMAIN RATHER COOL. DRY
CONDITIONS WITH SOMEWHAT WARMER TEMPERATURES ARE EXPECTED FRIDAY
THROUGH THE UPCOMING WEEKEND.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES OBSERVED OVER THE LOWER DESERT THIS MORNING...
WITH SOME RATHER FLAT CUMULIFORM CLOUD DEVELOPMENT LIMITED TO
EASTERN GILA COUNTY. WEAK SUBSIDENCE FORECAST OVER REGION IN WAKE OF
TROF PASSAGE LAST NIGHT...SO MOSTLY SUNNY SKY CONDITION EXPECTED
OVER THE LOWER DESERT TODAY...WITH JUST SCTD STRATOCUMULUS CLOUDS.
EVEN WITH PLENTY OF SUNSHINE...MAX TEMPS WILL BE 6-8 DEGREES BELOW
NORMAL AT MOST SITES TODAY...GIVEN OBSERVED BOUNDARY LAYER TEMPS.
FORECAST HIGH FOR PHOENIX...63 DEGREES...IS 7 DEGREES BELOW NORMAL
FOR THE DATE.
NEXT WEATHER SYSTEM TO AFFECT OUR FORECAST AREA IS CURRENTLY WEST OF
THE WASHINGTON-OREGON COAST. MORNING NUMERICAL MODELS IN EXCELLENT
AGREEMENT REGARDING EVOLUTION/TRACK OF THIS AREA OF LOW PRESSURE...
WITH 500 MB REFLECTION OF THE LOW NEAR SAN DIEGO BY 12Z
WEDNESDAY...AND NEAR ORGAN PIPE NM BY 00Z THURSDAY.
FROM PREVIOUS DISCUSSION...NEXT SHORT WAVE TROUGH...CURRENTLY
APPROACHING THE PAC NW COAST...WILL IMPACT OUR CWA BEGINNING LATE
TUESDAY AND CONTINUING THROUGH EARLY THURSDAY. OPERATIONAL AND
ENSEMBLE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND
INTENSITY OF THIS LOW THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A
STRONG H25 SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY
ROUGHLY STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST-NOT EXACTLY OPTIMAL FOR INGESTING MOIST AIR
FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE INTO
OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP WITH
LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT OF THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
KPHX...KIWA...KIPL...AND KBLH...
TYPICAL LIGHT DIURNAL WINDS ARE EXPECTED TODAY AND TONIGHT WITH A
FEW OR SCATTERED STRATOCUMULUS CLOUDS BETWEEN 5 AND 7 THOUSAND FEET.
INCREASING HIGH CIRRIFORM CLOUDINESS IS EXPECTED LATE TONIGHT AFTER
ABOUT 0800 GMT TUESDAY MORNING WELL AHEAD OF A PACIFIC STORM SYSTEM.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KLOX 081713
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
910 AM PST MON FEB 8 2010
.SYNOPSIS...
ANOTHER STORM WILL BRING SHOWERS AND LOW ELEVATION SNOW AS WELL AS A
SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA TUESDAY INTO EARLY
WEDNESDAY. DRY WEATHER AND COOLER TEMPERATURES ARE EXPECTED THROUGH
THE REST OF THE WEEK...WITH THE EXCEPTION OF SOME LIGHT SHOWERS
POSSIBLE ACROSS THE CENTRAL COAST ON FRIDAY.
&&
.SHORT TERM (TODAY-WED)...
SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES THIS MORNING EXCEPT
CONTINUED MOSTLY CLOUDY SKIES CONTINUING OVER THE NORTH SLOPES
AND INTERIOR VALLEYS OF SLO/SBA COUNTIES. THESE CLOUDS SHOULD
DIMINISH BY EARLY AFTERNOON. THERE COULD BE A SPRINKLE OR A FLURRY
WITH THESE CLOUDS OVER THE NORTH SLOPES. TODAY WILL BE PARTLY CLOUDY
AND COOL.
GENERAL FORECAST FOR TUESDAY AND EARLY WEDNESDAY REMAINS ON TRACK.
A COLD UPPER LOW WILL PINCH OFF FROM ITS PARENT PAC NW TROF AND WORK
ITS WAY DOWN THE COAST. IT WILL BRING A CHANCE OF SHOWERS TO THE
CENTRAL COAST BY TUESDAY MORNING. LATEST 12Z NAM/GFS GUIDANCE SHOW
THAT SHOWERS WILL LIKELY SPREAD ACROSS MUCH OF THE FORECAST AREA
BY TUESDAY AFTERNOON...SO WILL BE BUMPING UP POPS TO LIKELY IN ALL
AREAS DURING THAT TIME FRAME. OTHER UPCOMING CHANGE WILL BE LOWERING
OF SNOW LEVELS. PER COORDINATION WITH SAN DIEGO OFFICE...WILL HAVE
SNOW LEVELS BETWEEN 3500 AND 4000 FEET TUESDAY AFTERNOON...LOWERING
TO AS LOW AS 2000 FEET LATE TUESDAY NIGHT. WINTER STORM WATCH WILL
BE POSTED WITH AFTERNOON PACKAGE FOR LA/VTU COUNTY MOUNTAINS. AND
WILL HIGHLIGHT OTHER LOW SNOW LEVEL IMPACTS FOR OTHER AREAS IN UPCOMING
SPECIAL WEATHER STATEMENT. THE LOW SNOW LEVELS COULD BRING SIGNIFICANT
IMPACT TO MAJOR TRAFFIC CORRIDOR SUCH AS INTERSTATE 5 NORTH OF CASTAIC
AS WELL AS HIGHWAY 14 THROUGH SOLEDAD CANYON.
*** FROM PREVIOUS DISCUSSION ***
RAINFALL AMOUNTS WITH THIS SYSTEM WILL BE TRICKY. THE CURRENT
FORECAST CALLS FOR 0.50" TO 1.00" ACROSS COASTAL/VALLEY AREAS WITH
UP TO 1.50" IN THE MOUNTAINS. UNFORTUNATELY THE AMOUNT OF RAINFALL
IS GREATLY DEPENDENT ON THE TRACK OF THE STORM. THE CURRENT TRACK IS
ABOUT HALF OVER LAND HALF OVER WATER. IF THE STORM TRACKS MORE
EASTWARD THERE WILL BE LESS RAIN AND IF IT MOVE WESTWARD MORE OVER
THE WATER IT WILL BE WETTER. WITH THUNDERSTORMS NOW IN THE MIX THERE
WILL BE A FEW AREAS THAT GET MORE RAINFALL AND WITH GREATER RATES
THAN THE OVERALL STORM SYSTEM. EXCEPT FOR THE SMALL POSSIBILITY OF
A DIRECT TSTM HIT...THE BURN AREAS SHOULD NOT BE TOO THREATENED BY
THIS SYSTEM.
.LONG TERM (THU-SUN)...
GFS AND EC IN QUITE GOOD AGREEMENT FOR THE LONG TERM. THURSDAY WILL
BE UNEVENTFUL WITH A COOLISH 570DM RIDGE OVERHEAD. A WEAK FRONT WILL
ROLL THROUGH THE AREA FRIDAY. IT WILL CLOUD THINGS UP BUT WILL ONLY
BRING A CHC OF RAIN TO THE AREA NORTH OF POINT CONCEPTION AND JUST A
SLIGHT CHC SOUTH. RIDGING PUSHES INTO THE AREA SATURDAY AND LASTS
INTO SUNDAY. SKIES WILL BE...AT WORST...PARTLY CLOUDY. TEMPS WILL
RISE SOME BUT HGTS WILL ONLY BE AROUND 573 DM AND NOW THE OFFSHORE
FLOW DOES NOT LOOK AS STRONG AS IT DID YDY SO DO NOT LOOK FOR A BIG
WARM UP.
&&
.AVIATION...
08/1200
THE ONLY CLOUDS WILL BE ALONG THE NORTH SLOPES AND IN THE INTERIOR
VLYS OF SLO AND SBA COUNTIES. LOCAL NORTH WIND GUSTS TO 40 MPH
THROUGH AND BELOW PASSES AND CANYONS THIS MORNING.
KLAX AND KBUR...HIGH CONFIDENCE IN THE CURRENT TAFS.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...BRUNO
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 081710
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1009 AM MST MON FEB 8 2010
.SYNOPSIS...
MOSTLY CLEAR SKIES AND BELOW NORMAL TEMPERATURES WILL PERSIST
THROUGH TUESDAY. ANOTHER LOW PRESSURE SYSTEM WILL BRING A CHANCE FOR
RAIN AND MOUNTAIN SNOW SHOWERS TO FAR SOUTHEAST CALIFORNIA AND THE
LOWER COLORADO RIVER LATE TUESDAY NIGHT AND EARLY WEDNESDAY...AND TO
SOUTHWEST AND SOUTH-CENTRAL ARIZONA WEDNESDAY AND WEDNESDAY EVENING.
DRIER CONDITIONS WILL PREVAIL BY THURSDAY...THOUGH IT WILL REMAIN
RATHER COOL. DRY CONDITIONS WITH SOMEWHAT WARMER TEMPERATURES ARE
EXPECTED FRIDAY THROUGH THE UPCOMING WEEKEND.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES OBSERVED OVER THE LOWER DESERT THIS MORNING...
WITH SOME RATHER FLAT CUMULIFORM CLOUD DEVELOPMENT LIMITED TO
EASTERN GILA COUNTY. WEAK SUBSIDENCE FORECAST OVER REGION IN WAKE OF
TROF PASSAGE LAST NIGHT...SO MOSTLY SUNNY SKY CONDITION EXPECTED
OVER THE LOWER DESERT TODAY...WITH JUST SCTD STRATOCUMULUS CLOUDS.
EVEN WITH PLENTY OF SUNSHINE...MAX TEMPS WILL BE 6-8 DEGREES BELOW
NORMAL AT MOST SITES TODAY...GIVEN OBSERVED BOUNDARY LAYER TEMPS.
FORECAST HIGH FOR PHOENIX...63 DEGREES...IS 7 DEGREES BELOW NORMAL
FOR THE DATE.
NEXT WEATHER SYSTEM TO AFFECT OUR FORECAST AREA IS CURRENTLY WEST OF
THE WASHINGTON-OREGON COAST. MORNING NUMERICAL MODELS IN EXCELLENT
AGREEMENT REGARDING EVOLUTION/TRACK OF THIS AREA OF LOW PRESSURE...
WITH 500 MB REFLECTION OF THE LOW NEAR SAN DIEGO BY 12Z
WEDNESDAY...AND NEAR ORGAN PIPE NM BY 00Z THURSDAY.
FROM PREVIOUS DISCUSSION...NEXT SHORT WAVE TROUGH...CURRENTLY
APPROACHING THE PAC NW COAST...WILL IMPACT OUR CWA BEGINNING LATE
TUESDAY AND CONTINUING THROUGH EARLY THURSDAY. OPERATIONAL AND
ENSEMBLE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND
INTENSITY OF THIS LOW THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A
STRONG H25 SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY
ROUGHLY STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST-NOT EXACTLY OPTIMAL FOR INGESTING MOIST AIR
FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE INTO
OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP WITH
LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT OF THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
KPHX...KIWA...KIPL...AND KBLH...
TYPICAL LIGHT DIURNAL WINDS ARE EXPECTED TODAY AND TONIGHT WITH A
FEW OR SCATTERED STRATOCUMULUS CLOUDS BETWEEN 5 AND 7 THOUSAND FEET.
INCREASING HIGH CIRRIFORM CLOUDINESS IS EXPECTED LATE TONIGHT AFTER
ABOUT 0800 GMT TUESDAY MORNING WELL AHEAD OF A PACIFIC STORM SYSTEM.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...DG/INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KMTR 081650
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
850 AM PST MON FEB 8 2010
.DISCUSSION...AS OF 8:50 AM PST MONDAY...SHOWERS RETURN ON TUESDAY
WITH SNOW LEVELS EXPECTED DOWN AS LOW AS 2000 FEET. ANOTHER CHANCE
FOR RAIN LATE THURSDAY INTO FRIDAY.
VISIBLE SATELLITE IMAGE SHOWS CLOUDS ACROSS A GOOD PORTION OF THE
CWA THIS MORNING. TEMPERATURES STARTED OUT GENERALLY IN THE 40S
ALTHOUGH A FEW MID 30S WERE REPORTED IN NORTH BAY VALLEYS. WITH
PLENTY OF LOW LEVEL MOISTURE IN PLACE AND A WEAK ONSHORE/WESTERLY
GRADIENT AT THE SURFACE...CLOUDS WILL BE SLOW TO BURN OFF AND WILL
LIKELY KEEP TEMPERATURES FROM WARMING UP MUCH ABOVE THE MID 50S.
SHOWERS WILL RETURN TO THE AREA OVERNIGHT TONIGHT AS A COLD SYSTEM
DROPS DOWN FROM THE NNW. MODEL GUIDANCE HAD VARIED GREATLY WITH THE
TRACK OF THIS FEATURE BUT IS FINALLY SETTLING ON A SOLUTION WHICH
BRINGS THE TROUGH AXIS PARALLEL TO THE COAST AND THE UPPER LEVEL
LOW WEST OF POINT REYES EARLY TUESDAY MORNING. THE LOW WILL THEN
MOVE JUST TO THE WEST OF MONTEREY BAY BY EARLY TUESDAY AFTERNOON AND
CONTINUE TO THE SOUTH INTO WEDNESDAY. AS THE LOW TRACKS TO THE
SOUTH...MOISTURE WRAPPING AROUND IT WILL ROTATE INTO OUR CWA AND
SPREAD FROM THE COAST TO INLAND SPOTS. LATEST FORECAST SOUNDINGS
CONTINUE TO SHOW SOME INSTABILITY ALONG WITH FREEZING LEVELS AROUND
3000 FEET AND VERY LOW CONVECTIVE TEMPERATURES. THEREFORE...WILL KEEP
A MENTION OF THUNDER AND SMALL HAIL IN THE FORECAST. DESPITE THE 3000
FOOT FREEZING LEVEL...ANY STRONG CELLS COULD EASILY DUMP SNOW DOWN TO
THE 2000 FOOT MARK. TIMING BRINGS PRECIP TO SF CLOSE TO THE MORNING
RUSH WITH EAST BAY/SANTA CLARA LOOKING MORE LIKE A LATE MORNING
START. PRECIP TOTALS HAVE BE UPPED A BIT AS THE TRACK OF THE LOW IS
FAVORABLE FOR HIGHER AMOUNTS PARTICULARLY FOR SAN MATEO SOUTHWARD.
FINAL TOTALS SHOULD BE LESS THAN 1/4" FOR MAIN METRO AREAS WITH UP TO
1/2" FOR HIGHER ELEVATIONS...IN PARTICULAR THE SANTA CRUZ AND SANTA
LUCIA MOUNTAINS. SNOW ADVISORY CRITERIA ONLY REQUIRE 2" IN 12 HOURS
FOR SPOTS UNDER 3000 FEET AND FOR THOSE TWO AREAS THAT SEEMS LIKELY
TO HAPPEN. 4-7" IS NECESSARY ABOVE 3000 FEET AND CONSIDERING THE
FREEZING LEVEL WILL BE THAT LOW...IT CERTAINLY SEEMS POSSIBLE. WILL
LIKELY ISSUE A SNOW ADVISORY WITH THE AFTERNOON PACKAGE. FINALLY...
BASED ON THE TRACK...THIS DOES NOT LOOK FAVORABLE FOR SNOWFALL OVER
THE NORTH BAY HILLS. 50-50 CALL NEAR THE DIABLO RANGE. THE SYSTEM
WILL EXIT TUESDAY NIGHT.
AFTER A DRY DAY ON WEDNESDAY AND MUCH OF THURSDAY...ANOTHER TROUGH
WILL MOVE TO THE COAST THURSDAY NIGHT. THIS PROGRESSIVE FEATURE
WILL PUSH RAIN WEST TO EAST ACROSS THE CWA. UNLIKE THE
CONVECTIVE SYSTEM ON TUESDAY...700 MB TEMPS ONLY DROP TO AROUND MINUS
3 WHILE LIFTED VALUES REMAIN POSITIVE. RAINFALL AMOUNTS WILL
GENERALLY BE UNDER 1/3" WITH COASTAL MOUNTAINS LOOKING FOR UP TO AN
INCH AT THE MOST. DRY WEATHER IS STILL EXPECTED FOR THE WEEKEND.
&&
.AVIATION...AS OF 3:42 AM MONDAY...THE LATEST IR SATELLITE IMAGE IS
SHOWING CONSIDERABLE LOW LEVEL CLOUDS MOVING ACROSS THE DISTRICT
UNDER MOIST NORTHWEST FLOW. LOW LEVEL CLOUDS ARE EXPECTED TO MIX OUT
BY LATE MORNING AS HIGH PRESSURE SLIDES EVER SO SLOWLY EAST. A LOW
PRESSURE SYSTEM WILL MOVE INTO THE AREA EARLY TUESDAY MORNING
BRINGING A SHOT OF RAIN TO THE TERMINALS TUESDAY MORNING.
VICINITY OF KSFO...MVFR CIGS BKN021 EXPECTED TO MIX OUT BY 1700 Z.
VFR WILL THEN PERSIST FOR THE REMAINDER OF THE DAY. WEST WINDS 5 TO
10 KT EXPECTED THROUGH THIS EVENING. RAIN AND MVFR TO RETURN BY
1600 Z TUESDAY.
KSFO BRIDGE APPROACH...SAME AS KSFO.
MRY BAY AREA TERMINALS...MVFR CIGS BKN025 EXPECTED TO MIX OUT BY 1730
Z. VFR WILL THEN PERSIST FOR THE REMAINDER OF THE DAY. GENERALLY WEST
WINDS 5 TO 10 KT EXPECTED THIS AFTERNOON THROUGH EVENING. MVFR
BKN020 WILL RETURN BY 0200 Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: LARRY
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSGX 081649
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
850 AM PST MON FEB 8 2010
.SYNOPSIS...
DRY AND A LITTLE WARMER TODAY UNDER WEAK HIGH PRESSURE. A COLD LOW
PRESSURE SYSTEM FROM THE NORTHWEST WILL BRING MODERATE PRECIPITATION
AMOUNTS LATE TUESDAY INTO WEDNESDAY WITH LOW SNOW LEVELS AND A
CHANCE OF THUNDERSTORMS. WEAK HIGH PRESSURE FOR THURSDAY...THEN
ANOTHER CHANCE OF PRECIPITATION THURSDAY NIGHT AND FRIDAY WITH
WARMING AND DRYING FOR NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...
HIGH PRESSURE RIDGE AND WEAK OFFSHORE FLOW TODAY FOR TEMPORARY
DRYING AND WARMING. A VERY COLD LOW IN THE VICINITY OF 48N 135W...
WITH A CENTRAL HEIGHT OF 5350 METERS AT 500 MB...IS FORECAST BY ALL
MODELS TO DROP SOUTH SOUTHEAST ALONG THE WEST COAST TONIGHT/TUESDAY
THEN HOOK INLAND ACROSS SOUTHERN CALIFORNIA TUESDAY NIGHT/WEDNESDAY.
VERY LOW THICKNESS VALUES IN THE CENTER OF THIS LOW AND STRONG
DIVERGENCE ALOFT AHEAD OF IT AS IT MAKES THE TURN INLAND INDICATE
SNOW LEVELS AS LOW AS 2000 FEET ACROSS SOUTHWEST CALIFORNIA AND
SIGNIFICANT AMOUNTS OF PRECIPITATION. SEE HYDROLOGY SECTION BELOW.
IN THE AFTERNOON PACKAGE AM STRONGLY LEANING TOWARDS ISSUING A
WINTER STORM WATCH VALID LATE TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR THE MOUNTAINS AND A SPECIAL WEATHER STATEMENT...WHICH
MAY EVENTUALLY MORPH INTO WINTER WEATHER ADVISORIES...FOR THE HIGH
DESERTS/INLAND EMPIRE/SAN DIEGO COUNTY INLAND VALLEYS. WRAP AROUND
MOISTURE...SHOWERS AND THUNDERSTORMS WITH SMALL HAIL LIKELY TO
CONTINUE THROUGH WEDNESDAY AFTERNOON.
&&
.LONG TERM...THURSDAY THROUGH SUNDAY...FROM PREVIOUS DISCUSSION...
YET ANOTHER TROUGH OF LOW PRESSURE COULD BRING A CHANCE
OF PRECIPITATION FOR THURSDAY NIGHT AND FRIDAY WITH THE MORE CLOSED
AND WESTWARD SOLUTIONS OF THE GFS AND DGEX BETTER FITTING THE
DOMINANT PATTERN AND FAVORED OVER THE ECMWF. CLOSED LOW PRESSURE
LINGERING OVER ARIZONA WOULD SLOW WARMING FOR SATURDAY...WITH
GREATER WARMING TO NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES FOR
SUNDAY AND MONDAY.
&&
.AVIATION...
081445Z...PATCHY RADIATIONAL FOG THIS MORNING IN SOME OF THE INLAND
VALLEY AREAS SHOULD BE GONE BY 17Z. OTHERWISE A MOSTLY CLEAR SKY
WITH UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH TONIGHT. SOME
RADIATIONAL FOG MAY DEVELOP...AGAIN...AROUND SUNRISE TUESDAY IN THE
USUAL LOCATIONS NEAR KCNO...KAJO AND KRNM. EXPECT AN INCREASE IN MID
AND HIGH CLOUDS WITH BASES AT OR ABOVE FL150 TUESDAY AFTERNOON AND
LOWER STRATOCU/CU WITH BASES BETWEEN FL030 AND FL040. HORTON
&&
.MARINE...
BUOYS CONTINUE TO SHOW THE SWELLS OVER THE COASTAL WATERS DECREASING
AND WILL LET THE HIGH SURF ADVISORY EXPIRE ON SCHEDULE.
&&
.HYDROLOGY...
FROM PREVIOUS DISCUSSION ON PRECIPITATION TIMING...LIGHT
PRECIPITATION MAY DEVELOP IN ADVANCE OF THE SYSTEM DURING THE DAY
TUESDAY...MAINLY OVER NORTHWEST AREAS. A PERIOD OF MODERATE
PRECIPITATION IS EXPECTED FOR MOST AREAS TUESDAY NIGHT WITH SHOWERS
LINGERING INTO WEDNESDAY. PERIODS OF HIGH INTENSITY PRECIPITATION
ARE POSSIBLE TUESDAY NIGHT AND EARLY WEDNESDAY.
CURRENT WATER EQUIVALENT QPF AMOUNTS ARE...
FOR ORANGE COUNTY/SW SAN BERNARDINO COUNTY...0.50 TO 1.00 INCHES AT
THE COAST TO 1.5 TO 2.5 INCHES ON THE COASTAL SLOPES...AND 0.50
INCHES HIGH DESERT VALLEY FLOORS.
FOR WESTERN RIVERSIDE/SAN DIEGO COUNTIES...0.50 TO 0.75 INCHES AT
THE COAST TO 1 TO 2 INCHES COASTAL SLOPES....AND 0.25 INCHES LOWER
DESERT VALLEY FLOORS.
REVISED SNOW FORECAST AMOUNTS...USING TEN TO ONE RATIO...
ABOVE 4500 FEET SAN GABRIEL/SAN BERNARDINO MOUNTAINS...12 TO 24 IN.
ABOVE 4500 FEET IN ORANGE/RIVERSIDE/SAN DIEGO COUNTIES...6 TO 12 IN.
ELEVATIONS 3500 TO 4500 FEET...2 TO 6 IN.
ELEVATIONS 2000 TO 3500 FT...TRACE TO 1 INCH.
HAIL ACCUMULATIONS WEDNESDAY COULD ADD ANOTHER INCH OR TWO AT LOWER
ELEVATIONS.
AM CONSIDERING USING A HIGHER SNOW TO WATER RATIO...TWELVE TO
ONE...ON WEDNESDAY WHICH WOULD BOOST ABOVE NUMBERS BY A FEW INCHES.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 10 AM PST THIS MORNING FOR SAN DIEGO
COUNTY COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS66 KHNX 081628
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
828 AM PST MON FEB 8 2010
.SYNOPSIS...
LOW CLOUDS AND FOG WILL PERSIST FOR MUCH OF TODAY THROUGH THE SAN
JOAQUIN VALLEY. SOME CLEARING CAN BE EXPECTED OVER THE NORTHERN AND
WESTERN REGIONS. THE NEXT FRONTAL SYSTEM WILL MOVE THROUGH THE
REGION TUESDAY NIGHT THROUGH WEDNESDAY PRODUCING RAIN AND HIGHER
ELEVATION SNOW.
&&
.DISCUSSION...RADAR STILL DEPICTS A FEW VERY LIGHT SPRINKLES OR
DRIZZLE IN THE VALLEY. ONE OR TWO BREAKS IN THE CLOUDS IN KERN
COUNTY OTHERWISE THE VALLEY AND SURROUNDING FOOTHILLS/MOUNTAINS
BELOW ABOUT 6000 FEET IS SOLIDLY CLOUDY. ISSUING AN UPDATE THIS
MORNING FOR A MOCLDY DAY EXCEPT OVER THE HIGH SIERRA WHERE THERE
COULD BE PLENTY OF SUNSHINE BEFORE HIGH CLOUDS BEGIN TO INCREASE
THIS AFTERNOON. NO OTHER CHANGES FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 410 AM PST MON FEB 8 2010/
DISCUSSION...MOST OF THE LINGERING LIGHT SHOWERS IN THE CYCLONIC
FLOW BEHIND THE DEPARTING UPPER LOW HAVE NOW DISSIPATED ACROSS THE
AREA. DESERT ZONES HAVE GENERALLY CLEAR SKIES...OTHERWISE A SOLID
CLOUD DECK COVERS MOST OF THE DISTRICT...WITH A LITTLE PATCHY FOG
IN THE CENTRAL VALLEY.
EXPECT A BRIEF BREAK FROM THE RECENT WET CONDITIONS TODAY AS WEAK
RIDGING SETS UP OVERHEAD. BY LATER TONIGHT PRECIPITATION MAY BEGIN
EDGING IN FROM THE NORTH IN ADVANCE OF THE NEXT APPROACHING
SYSTEM. MODELS ARE IN AGREEMENT DROPPING THE DEVELOPING UPPER LOW
DOWN THE CENTRAL COAST TUESDAY AND INTO CENTRAL CALIFORNIA BY
TUESDAY NIGHT/WEDNESDAY. THIS WILL SPREAD PRECIPITATION ACROSS THE
DISTRICT WITH SOME THUNDER POSSIBLE IN THE VALLEY AND DESERT ZONES
AS THE COLD UPPER LOW MOVES OVERHEAD. SNOW LEVELS WILL BE QUITE
LOW IN KERN COUNTY AS THE COLD SYSTEM SETTLES IN...AND A SPECIAL
WEATHER STATEMENT CONTINUES TO HIGHLIGHT THE EXPECTED WINTRY
WEATHER IN THE KERN COUNTY MOUNTAINS AND DESERTS.
THURSDAY BRINGS MORE RIDGING AND POSSIBLE VALLEY FOG AHEAD OF THE
NEXT SYSTEM PROGGED TO BRUSH THE DISTRICT FRIDAY. THIS WILL BRING
MORE PRECIPITATION CHANCES ACROSS THE DISTRICT FRIDAY WITH SNOW
LEVELS BACK UP TO A MORE NORMAL RANGE IN THE 5 TO 6 THOUSAND FOOT
NEIGHBORHOOD. THIS SYSTEM WILL THEN BE REPLACED AGAIN BY MORE
HIGH PRESSURE BUILDING INTO THE REGION...CONTINUING INTO THE FIRST
PART OF NEXT WEEK WITH MORE VALLEY FOG AND A GENERAL WARMING TREND
ACROSS THE DISTRICT.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...AREAS OF MVFR AND LOCAL IFR IN BR/FG
UNTIL 19Z...THEN VFR PREVAILING THROUGH 06Z TUES...LCL MVFR IN BR
FROM 06Z-12Z TUESDAY. IN THE SIERRA NEVADA AND TEHACHAPI
MOUNTAINS...AREAS OF IFR CIGS AND MOUNTAIN OBSCURATIONS THROUGH
18Z MON BECOMING MAINLY VFR THROUGH 06Z TUESDAY...THEN LOWERING
CEILINGS WITH -RA SPREADING IN FROM THE NORTH AFTER FROM 08Z-12Z
TUESDAY. IN THE KERN COUNTY DESERT...VFR THROUGH 12Z TUES.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BINGHAM/JEB
AVN/FW...BEAN/DCH
SYNOPSIS...WP
WEATHER.GOV/HANFORD
000
FXUS65 KPSR 081241 AAB
AFDPSR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
540 AM MST MON FEB 8 2010
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
PARTLY CLOUDY SKIES AND SEASONABLE TEMPERATURES ARE EXPECTED THROUGH
TUESDAY. A QUICK MOVING LOW PRESSURE SYSTEM WILL DROP OUT OF
CALIFORNIA...MOVE ACROSS SOUTHERN ARIZONA AND BRING A CHANCE OF RAIN
AND MOUNTAIN SNOW TO MOST OF THE REGION BY WEDNESDAY. HIGH PRESSURE
WILL RETURN THURSDAY LEADING TO MORE SUNSHINE AND WARMER WEATHER
HEADING INTO THE WEEKEND.
&&
.DISCUSSION...
RADAR ECHOES HAVE SUBSIDED THIS MORNING AS THE FINAL VORT MAX
ROTATING AROUND THE CLOSED LOW NEAR THE FOUR CORNERS EXITS OUR CWA.
H5 HEIGHTS WILL BE INCREASING TODAY INTO TUESDAY ALLOWING A DRY
FORECAST TO PREVAIL.
NEXT SHORT WAVE TROUGH...CURRENTLY APPROACHING THE PAC NW
COAST...WILL IMPACT OUR CWA BEGINNING LATE TUESDAY AND CONTINUING
THROUGH EARLY THURSDAY. OPERATIONAL AND ENSEMBLE MODELS ARE
GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND INTENSITY OF THIS LOW
THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A STRONG H25
SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY ROUGHLY
STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST - NOT EXACTLY OPTIMAL FOR INGESTING MOIST
AIR FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE
INTO OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP
WITH LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT AS THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
KPHX...KIWA...KIPL...AND KBLH...
TYPICAL LIGHT DIURNAL WINDS ARE EXPECTED TODAY AND TONIGHT WITH A
FEW OR SCATTERED STRATOCUMULUS CLOUDS BETWEEN 5 AND 7 THOUSAND FEET.
INCREASING HIGH CIRRIFORM CLOUDINESS IS EXPECTED LATE TONIGHT AFTER
ABOUT 0800 GMT TUESDAY MORNING WELL AHEAD OF A PACIFIC STORM SYSTEM.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY NIGHT THROUGH SUNDAY...
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EAST-SOUTHEAST ACROSS
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY AND SOUTHERN ARIZONA
NEAR THE MEXICAN BORDER WEDNESDAY NIGHT. THIS SYSTEM WILL BRING RAIN
AND MOUNTAIN SNOW SHOWERS MAINLY TO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA TUESDAY NIGHT...AND ESPECIALLY TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA WEDNESDAY.
SOME LINGERING SHOWERS ARE EXPECTED WEDNESDAY NIGHT...MAINLY EAST OF
PHOENIX. IT WILL ALSO BE COOLER WEDNESDAY WITH HIGHER RELATIVE
HUMIDITY.
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING A RETURN TO
RELATIVELY DRIER AIR AND A RECOVERY OF TEMPERATURES THURSDAY AND
FRIDAY WITH FURTHER WARMING THIS COMING WEEKEND. HOWEVER...MINIMUM
RELATIVE HUMIDITY IS EXPECTED TO STAY ABOVE 25 PERCENT WITH GOOD TO
EXCELLENT RECOVERY AT NIGHT. SOME WIND FROM THE NORTH IS EXPECTED IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS WEEKEND...ESPECIALLY
DOWN THE LOWER COLORADO RIVER VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...ELLIS
FIRE WEATHER...ELLIS
000
FXUS66 KEKA 081216
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
416 AM PST MON FEB 8 2010
.SYNOPSIS...A WEAK DISTURBANCE WILL BRING RAIN AND HIGH ELEVATION
SNOW TO THE AREA TONIGHT INTO TUESDAY. MORE PRECIPITATION IS
POSSIBLE ON THURSDAY.
&&
.DISCUSSION...A TROUGH AND ASSOCIATED WEAK DISTURBANCE IS
APPROACHING NORTHWEST CALIFORNIA. RADAR IS HINTING AT SOME LIGHT
PRECIPITATION APPROACHING THE REDWOOD COAST AT THIS TIME, SO PUT
PATCHY DRIZZLE INTO THE COASTAL LAND FORECAST FOR THIS MORNING
FOLLOWED BY A SLIGHT CHANCE OF LIGHT RAIN FOR THE LATE MORNING AND
AFTERNOON. MODELS ARE IN GOOD AGREEMENT SHOWING THE PRECIPITATION
MOVING THROUGH LATE THIS EVENING AND OVERNIGHT. MODELS ALSO SHOW
MORE COLD AIR, SO LOWERED SNOW LEVELS ABOUT 500 FT. QPF WILL BE
MINIMAL WITH TOTALS UNDER 0.25 INCHES AND SNOW ACCUMULATIONS BELOW
5,500 FT WILL BE NEAR 2 INCHES MAX. ALSO PUSHED THE THUNDERSTORM
THREAT BACK BY 6 HOURS SINCE THE MODELS SHOW THE COLD AIR ALOFT
AND THE ASSOCIATED INSTABILITY THAT IT WILL CREATE SLOWING DOWN.
BUT THE THUNDERSTORM THREAT REMAINS MINIMAL. PRECIPITATION WILL
DIMINISH ON TUESDAY AND HIGH PRESSURE WILL BUILD IN WEDNESDAY.
MORE PRECIPITATION IS LIKELY ON THURSDAY FROM ANOTHER FRONT.
THOUGH MODELS HAVE BEEN SLOWING THIS DOWN. STROZ
&&
.AVIATION...AN APPROACHING TROUGH ALOFT WILL BRING A FEW SHOWERS
TO THE REGION TODAY. SHOWER ACTIVITY AND COVERAGE WILL INCREASE
TONIGHT AS THE LOW MOVES CLOSER TO THE COAST AND GUSTY WINDS
DEVELOP. DJB
&&
.MARINE...HIGH PRES OVER THE E PAC WILL GENERATE A MODERATE
NORTHERLY WIND SURGE TONIGHT THROUGH TUE. A WEAK LOW WILL APPROACH
ON WED AND BRING A THREAT OF SOUTHERLY GALES BY THU. W SWELL FROM
THIS STORM WILL ARRIVE ON FRI. DJB
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY PZZ450-455-470-475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KHNX 081210
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
410 AM PST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY CONTROL THE WEATHER OVER THE REGION
TODAY BEFORE ANOTHER STORM SYSTEM BRINGS THE CHANCE OF RAIN AND
SNOW TUESDAY THROUGH WEDNESDAY.
&&
.DISCUSSION...MOST OF THE LINGERING LIGHT SHOWERS IN THE CYCLONIC
FLOW BEHIND THE DEPARTING UPPER LOW HAVE NOW DISSIPATED ACROSS THE
AREA. DESERT ZONES HAVE GENERALLY CLEAR SKIES...OTHERWISE A SOLID
CLOUD DECK COVERS MOST OF THE DISTRICT...WITH A LITTLE PATCHY FOG
IN THE CENTRAL VALLEY.
EXPECT A BRIEF BREAK FROM THE RECENT WET CONDITIONS TODAY AS WEAK
RIDGING SETS UP OVERHEAD. BY LATER TONIGHT PRECIPITATION MAY BEGIN
EDGING IN FROM THE NORTH IN ADVANCE OF THE NEXT APPROACHING
SYSTEM. MODELS ARE IN AGREEMENT DROPPING THE DEVELOPING UPPER LOW
DOWN THE CENTRAL COAST TUESDAY AND INTO CENTRAL CALIFORNIA BY
TUESDAY NIGHT/WEDNESDAY. THIS WILL SPREAD PRECIPITATION ACROSS THE
DISTRICT WITH SOME THUNDER POSSIBLE IN THE VALLEY AND DESERT ZONES
AS THE COLD UPPER LOW MOVES OVERHEAD. SNOW LEVELS WILL BE QUITE
LOW IN KERN COUNTY AS THE COLD SYSTEM SETTLES IN...AND A SPECIAL
WEATHER STATEMENT CONTINUES TO HIGHLIGHT THE EXPECTED WINTRY
WEATHER IN THE KERN COUNTY MOUNTAINS AND DESERTS.
THURSDAY BRINGS MORE RIDGING AND POSSIBLE VALLEY FOG AHEAD OF THE
NEXT SYSTEM PROGGED TO BRUSH THE DISTRICT FRIDAY. THIS WILL BRING
MORE PRECIPITATION CHANCES ACROSS THE DISTRICT FRIDAY WITH SNOW
LEVELS BACK UP TO A MORE NORMAL RANGE IN THE 5 TO 6 THOUSAND FOOT
NEIGHBORHOOD. THIS SYSTEM WILL THEN BE REPLACED AGAIN BY MORE
HIGH PRESSURE BUILDING INTO THE REGION...CONTINUING INTO THE FIRST
PART OF NEXT WEEK WITH MORE VALLEY FOG AND A GENERAL WARMING TREND
ACROSS THE DISTRICT.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...AREAS OF MVFR AND LOCAL IFR IN BR/FG
UNTIL 19Z...THEN VFR PREVAILING THROUGH 06Z TUES...LCL MVFR IN BR
FROM 06Z-12Z TUESDAY. IN THE SIERRA NEVADA AND TEHACHAPI
MOUNTAINS...AREAS OF IFR CIGS AND MOUNTAIN OBSCURATIONS THROUGH
18Z MON BECOMING MAINLY VFR THROUGH 06Z TUESDAY...THEN LOWERING
CEILINGS WITH -RA SPREADING IN FROM THE NORTH AFTER FROM 08Z-12Z
TUESDAY. IN THE KERN COUNTY DESERT...VFR THROUGH 12Z TUES.
&&
.AIR QUALITY ISSUES...
NONE
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JEB
AVN/FW...DCH
SYNOPSIS...PJ
WEATHER.GOV/HANFORD
000
FXUS66 KSTO 081207
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
405 AM PST MON FEB 8 2010
.DISCUSSION...
INTERIOR NORTHERN CALIFORNIA CURRENTLY UNDER THE INFLUENCE OF
SHORTWAVE RIDGING. WHILE MUCH OF THE AREA SAW MOSTLY CLEAR SKIES
THROUGH THE LATE EVENING AND EARLY MORNING HOURS...AN AREA OF LOW
STRATUS FORMED OVER THE SIERRA FOOTHILLS AND HAS BEEN STEADILY
SPREADING WESTWARD EARLY THIS MORNING. GENERALLY SOUTH OF
MARYSVILLE/YUBA CITY...THIS STRATUS DECK SHOULD LIKELY EFFECTIVELY
ELIMINATE ANY CHANCE OF DENSE FOG FORMATION IN THE SOUTHERN
SACRAMENTO AND NORTHERN SAN JOAQUIN VALLEYS THIS MORNING. WITH
SEVERAL HOURS OF GOOD RADIATIONAL COOLING...MOST LOWER ELEVATION
LOCALITIES ARE RUNNING SEVERAL DEGREES COOLER THAN 24 HOURS AGO.
LOOKING UPSTREAM...STARTING TO SEE HIGH CLOUDS APPROACHING NORTHERN
CALIFORNIA IN ASSOCIATION WITH A DECAYING FRONTAL SYSTEM. THIS
SYSTEM MAY PRODUCE A FEW ISOLATED SHOWERS TO THE MOUNTAINS GENERALLY
NORTH OF INTERSTATE-80 THIS AFTERNOON BUT SHOULD REMAIN OF LITTLE
IMPACT.
VORTEX CURRENTLY VISIBLE ON IR SATELLITE NEAR 49N 135W OFF THE
VANCOUVER ISLAND COAST WILL BE THE NEXT WEATHER SYSTEM TO IMPACT
NORTHERN CALIFORNIA...AS EARLY AS LATE TONIGHT TOWARDS THE NORTHERN
AND COASTAL MOUNTAINS. THE MODEL CONSENSUS IS FOR THE UPPER SYSTEM
TO FORM A CLOSED UPPER LOW THIS AFTERNOON OFF THE PACIFIC NORTHWEST
COAST...AND NEARLY PARALLEL THE NORTHERN CALIFORNIA COAST LATE
TONIGHT INTO TUESDAY BEFORE DROPPING SOUTH INTO CENTRAL/SOUTHERN CAL
TUESDAY NIGHT. THIS SYSTEM LACKS A SIGNIFICANT MOISTURE PLUME AND
THUS MOST AREAS SHOULD ONLY SEE LIGHT PRECIPITATION. HOWEVER...WITH
THE COLD NATURE OF THE UPPER LOW AND SUBSEQUENT INSTABILITY CANT
RULE OUT HEAVIER DOWNPOURS IN SHOWERS OR EVEN A SLIGHT CHANCE OF A
FEW THUNDERSTORMS. SNOW LEVELS SHOULD DIP DOWN TO AROUND 3000 FEET
OR POSSIBLY A BIT LOWER TONIGHT AND RISE TO PERHAPS 3500 TO 4500
FEET TUESDAY.
THE SYSTEM WILL QUICKLY EXIT THE AREA BY TUESDAY EVENING. AN UPPER
RIDGE WILL QUICKLY BUILD INTO NORTHERN CALIFORNIA...PROVIDING
ENHANCED SUBSIDENCE AND CLEARING SKIES FOR TUESDAY NIGHT. WITH THE
COLD AIRMASS ALREADY IN PLACE AND GOOD RADIATIONAL COOLING
EXPECTED...TUESDAY NIGHT COULD BE FAIRLY COLD WITH TEMPERATURES
THROUGH THE VALLEY DIPPING INTO THE MID TO UPPER 30S.
SOME OVERRUNNING PRECIPITATION MAY IMPACT THE FAR NORTH ON WEDNESDAY
AND THURSDAY BUT OTHERWISE WEDNESDAY AND THURSDAY TIMEFRAME LOOK
MAINLY DRY. OVERNIGHT AND EARLY MORNING FOG WILL BE A POSSIBILITY
TOWARDS THE SOUTHERN SACRAMENTO/NORTHERN SAN JOAQUIN VALLEYS AND
NEAR THE DELTA DURING THIS TIMEFRAME. DANG
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...
MODELS ARE IN GOOD AGREEMENT IN MOVING AN OPEN WAVE ACROSS INTERIOR
NORCAL ON FRI BRINGING A CHANCE OF PRECIP TO THE AREA. QPFS ARE
FORECAST TO BE HEAVIER ALONG THE COAST...BUT LIGHTER OVER THE
INTERIOR OF NORCAL...GENERALLY MORE IN THE .10 TO .30 INCH RANGE...A
WEAK TO MODEST SYSTEM AT BEST. THE OPEN WAVE IS FORECAST TO MOVE
INTO THE DESERT SW ALLOWING A POSITIVELY TILTED RIDGE TO BUILD OVER
NORCAL FOR THE WEEKEND...AND AHEAD OF A DEVELOPING GULF OF AK/ERN
PAC LONGER WAVE TROF. WE HAVE GONE WITH A DRY FORECAST FOR THE
WEEKEND AS ANY WAA PCPN IS EXPECTED TO STAY N AND W OF INTERIOR
NORCAL. THIS WILL BE A SEASONABLY MILD PATTERN WITH NEAR NORMAL
TEMPS AROUND 60 IN THE VALLEY...ALBEIT VALLEY STRATUS/FOG IS STILL A
MORNING CONCERN. THE AFOREMENTIONED DEVELOPING TROF IS FORECAST TO
MOVE INLAND SUN NITE AND MON WITH THE NEXT CHANCE OF PCPN. JHM
&&
.AVIATION...THE LOWER CLOUDS BANKED UP AGAINST THE FOOTHILLS OF THE
SIERRA...WITH MVFR CIGS...HAVE USED THE BACKDOOR AND SPREAD TO THE
SW INTO THE SRN SAC AND NRN SAN JOAQUIN VALLEYS. THE WRN OR LEADING
EDGE OF THE CLOUDS WAS LOCATED FROM KBAB-KSAC-RIO VISTA IN THE DELTA
AT 11Z. CIGS ARE GENERALLY AOA 4 KFT AT THE TAF SITES...LOWER IN THE
FOOTHILLS AND OCNLY MVFR CIGS. WATER VAPOR IMAGERY SHOWS A WEAK TROF
AND WEAKENING COLD FRONT MOVING INSIDE 130W AND APPROACHING THE
COAST. THIS SYSTEMS IS SHIFTING THE NARROW RIDGE AXIS INLAND AND
ALSO SHIFTING THE CYCLONIC/BACKWASH FLOW TO THE E. THIS MAY RETARD
THE WRN ADVANCE OF THE LOW CLOUDS THIS MORNING. THE ADVANCE OF THE
LOW CLOUDS WILL PRECLUDE RADIATION FOG FROM FORMING EVEN THO TEMP/TD
SPREADS ARE NARROW. AS FOR THE NRN SAC VLY...THE LIGHT DOWNSLOPE
WIND SHOULD PRECLUDE DENSE FOG THERE THIS MORNING.
MODELS ARE NOT HANDLING THE STRATOCUMULUS DECK IN THE SRN SAC/NRN SJ
VLYS WELL...BUT THE STRATOCUMULUS DECK IN THE VLY IS LIKELY TO ERODE
LATE MORNING OR AFTERNOON AS THE CYCLONIC/BACKWASH FLOW CONTINUES TO
SHIFT EWD. THE STRONGER UPSTREAM SYSTEM NEARING 140W IS EXPECTED TO
MOVE INTO THE AREA AFTER 06Z TUE...SPREADING MVFR CIGS AND SHOWERS
OVER THE INTERIOR OF NORCAL. BUFKIT FORECAST SOUNDINGS HOLD OFF ON
SHOWERS IN THE SRN SAC AND NRN SJ VALLEYS UNTIL AFT 12Z TUE.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KLOX 081205
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
350 AM PST MON FEB 8 2010
.SYNOPSIS...
IT WILL BE PARTLY CLOUDY AND DRY TODAY...EXCEPT FOR MOSTLY CLOUDY
SKIES OVER THE NORTH SLOPES AND THE INTERIORS OF SAN LUIS OBISBO
AND SANTA BARBARA COUNTIES. ANOTHER STORM WILL BRING RAIN AND LOW
ELEVATION SNOW AS WELL AS A SLIGHT CHANCE OF THUNDERSTORMS TO THE
AREA TUESDAY INTO EARLY WEDNESDAY. DRY WEATHER AND COOLER
TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH THE
EXCEPTION OF SOME LIGHT SHOWERS POSSIBLE ACROSS THE CENTRAL COAST ON
FRIDAY.
&&
.SHORT TERM (TODAY-WED)...
MOSTLY CLOUDY SKIES CONTINUE OVER THE NORTH SLOPES AND THE INTERIOR
OF SLO AND SBA COUNTIES. THESE CLOUDS SHOULD DIMINISH BY EARLY
AFTERNOON. THERE COULD BE A SPRINKLE OR A FLURRY WITH THESE CLOUDS
OVER THE NORTH SLOPES. NORTH FLOW HAS CREATED LOCAL NORTH WINDS TO
40 MPH THROUGH AND BELOW THE PASSES OF SOUTHERN SBA COUNTY...THESE
WINDS WILL DIMINISH LATER THIS MORNING. OTHERWISE TODAY WILL BE
PARTLY CLOUDY AND COOL.
GENERAL FORECAST FOR TUESDAY AND EARLY WEDNESDAY REMAINS ON TRACK. A
UPPER LOW WILL PINCH OFF FROM ITS PARENT PAC NW TROF AND WORK ITS
WAY DOWN THE COAST. IT WILL BRING A CHANCE OF RAIN TO THE CENTRAL
COAST BY TUESDAY MORNING. BY TUESDAY AFTERNOON RAIN WILL BECOME
LIKELY ACROSS THE CENTRAL COAST AND THEN RAIN WILL LIKELY OVERSPREAD
THE AREA SOUTH OF POINT CONCEPTION TUESDAY NIGHT. A NICE COLD POCKET
WITH 500 MB TEMPS OF -29 DEGREES C GOES OVER THE AREA TUE AFTERNOON
AND OVERNIGHT. THIS WILL DESTABILIZE THINGS ENOUGH TO WARRANT A
SLIGHT CHC OF TSTMS. THE SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY
MORNING WITH THE CHC OF SHOWERS ENDING BY LATE WED MORNING WITH THE
EXCEPTION OF THE NORTH SLOPES WHICH WILL STAY CLOUDY WITH A CHANCE
OF SHOWERS DUES TO NORTH FLOW WRAP AROUND. TUESDAY WILL BE COOL WITH
DUE TO THE CLOUDS AND RAIN AND DESPITE SOME AFTERNOON SUNSHINE
WEDNESDAY WILL BE THE SAME OR EVEN COOLER DUE TO 538DM THKNS
OVERHEAD IN THE WAKE OF THE LOW.
RAINFALL AMOUNTS WITH THIS SYSTEM WILL BE TRICKY. THE CURRENT
FORECAST CALLS FOR 0.50" TO 1.00" ACROSS COASTAL/VALLEY AREAS WITH
UP TO 1.50" IN THE MOUNTAINS. UNFORTUNATELY THE AMOUNT OF RAINFALL
IS GREATLY DEPENDENT ON THE TRACK OF THE STORM. THE CURRENT TRACK IS
ABOUT HALF OVER LAND HALF OVER WATER. IF THE STORM TRACKS MORE
EASTWARD THERE WILL BE LESS RAIN AND IF IT MOVE WESTWARD MORE OVER
THE WATER IT WILL BE WETTER. WITH THUNDERSTORMS NOW IN THE MIX THERE
WILL BE A FEW AREAS THAT GET MORE RAINFALL AND WITH GREATER RATES
THAN THE OVERALL STORM SYSTEM. EXCEPT FOR THE SMALL POSSIBILITY OF
A DIRECT TSTM HIT...THE BURN AREAS SHOULD NOT BE TOO THREATENED BY
THIS SYSTEM. SNOW LEVELS WILL BE RATHER LOW WITH THIS COLD SYSTEM
THEY WILL START OUT AT 5000 FEET BUT WILL QUICKLY DROP TO 4000 FEET
AND THEN DOWN TO NEAR 3000 FEET BY MID MORNING WEDNESDAY.
.LONG TERM (THU-SUN)...
GFS AND EC IN QUITE GOOD AGREEMENT FOR THE LONG TERM. THURSDAY WILL
BE UNEVENTFUL WITH A COOLISH 570DM RIDGE OVERHEAD. A WEAK FRONT WILL
ROLL THROUGH THE AREA FRIDAY. IT WILL CLOUD THINGS UP BUT WILL ONLY
BRING A CHC OF RAIN TO THE AREA NORTH OF POINT CONCEPTION AND JUST A
SLIGHT CHC SOUTH. RIDGING PUSHES INTO THE AREA SATURDAY AND LASTS
INTO SUNDAY. SKIES WILL BE...AT WORST...PARTLY CLOUDY. TEMPS WILL
RISE SOME BUT HGTS WILL ONLY BE AROUND 573 DM AND NOW THE OFFSHORE
FLOW DOES NOT LOOK AS STRONG AS IT DID YDY SO DO NOT LOOK FOR A BIG
WARM UP.
&&
.AVIATION...
08/1200
THE ONLY CLOUDS WILL BE ALONG THE NORTH SLOPES AND IN THE INTERIOR
VLYS OF SLO AND SBA COUNTIES. LOCAL NORTH WIND GUSTS TO 40 MPH
THROUGH AND BELOW PASSES AND CANYONS THIS MORNING.
KLAX AND KBUR...HIGH CONFIDENCE IN THE CURRENT TAFS.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...RORKE
AVIATION...BRUNO
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KLOX 081149
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
350 AM PST MON FEB 8 2010
.SYNOPSIS...
IT WILL BE PARTLY CLOUDY AND DRY TODAY...EXCEPT FOR MOSTLY CLOUDY
SKIES OVER THE NORTH SLOPES AND THE INTERIORS OF SAN LUIS OBISBO
AND SANTA BARBARA COUNTIES. ANOTHER STORM WILL BRING RAIN AND LOW
ELEVATION SNOW AS WELL AS A SLIGHT CHANCE OF THUNDERSTORMS TO THE
AREA TUESDAY INTO EARLY WEDNESDAY. DRY WEATHER AND COOLER
TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH THE
EXCEPTION OF SOME LIGHT SHOWERS POSSIBLE ACROSS THE CENTRAL COAST ON
FRIDAY.
&&
.SHORT TERM (TODAY-WED)...
MOSTLY CLOUDY SKIES CONTINUE OVER THE NORTH SLOPES AND THE INTERIOR
OF SLO AND SBA COUNTIES. THESE CLOUDS SHOULD DIMINISH BY EARLY
AFTERNOON. THERE COULD BE A SPRINKLE OR A FLURRY WITH THESE CLOUDS
OVER THE NORTH SLOPES. NORTH FLOW HAS CREATED LOCAL NORTH WINDS TO
40 MPH THROUGH AND BELOW THE PASSES OF SOUTHERN SBA COUNTY...THESE
WINDS WILL DIMINISH LATER THIS MORNING. OTHERWISE TODAY WILL BE
PARTLY CLOUDY AND COOL.
GENERAL FORECAST FOR TUESDAY AND EARLY WEDNESDAY REMAINS ON TRACK. A
UPPER LOW WILL PINCH OFF FROM ITS PARENT PAC NW TROF AND WORK ITS
WAY DOWN THE COAST. IT WILL BRING A CHANCE OF RAIN TO THE CENTRAL
COAST BY TUESDAY MORNING. BY TUESDAY AFTERNOON RAIN WILL BECOME
LIKELY ACROSS THE CENTRAL COAST AND THEN RAIN WILL LIKELY OVERSPREAD
THE AREA SOUTH OF POINT CONCEPTION TUESDAY NIGHT. A NICE COLD POCKET
WITH 500 MB TEMPS OF -29 DEGREES C GOES OVER THE AREA TUE AFTERNOON
AND OVERNIGHT. THIS WILL DESTABILIZE THINGS ENOUGH TO WARRANT A
SLIGHT CHC OF TSTMS. THE SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY
MORNING WITH THE CHC OF SHOWERS ENDING BY LATE WED MORNING WITH THE
EXCEPTION OF THE NORTH SLOPES WHICH WILL STAY CLOUDY WITH A CHANCE
OF SHOWERS DUES TO NORTH FLOW WRAP AROUND. TUESDAY WILL BE COOL WITH
DUE TO THE CLOUDS AND RAIN AND DESPITE SOME AFTERNOON SUNSHINE
WEDNESDAY WILL BE THE SAME OR EVEN COOLER DUE TO 538DM THKNS
OVERHEAD IN THE WAKE OF THE LOW.
RAINFALL AMOUNTS WITH THIS SYSTEM WILL BE TRICKY. THE CURRENT
FORECAST CALLS FOR 0.50" TO 1.00" ACROSS COASTAL/VALLEY AREAS WITH
UP TO 1.50" IN THE MOUNTAINS. UNFORTUNATELY THE AMOUNT OF RAINFALL
IS GREATLY DEPENDENT ON THE TRACK OF THE STORM. THE CURRENT TRACK IS
ABOUT HALF OVER LAND HALF OVER WATER. IF THE STORM TRACKS MORE
EASTWARD THERE WILL BE LESS RAIN AND IF IT MOVE WESTWARD MORE OVER
THE WATER IT WILL BE WETTER. WITH THUNDERSTORMS NOW IN THE MIX THERE
WILL BE A FEW AREAS THAT GET MORE RAINFALL AND WITH GREATER RATES
THAN THE OVERALL STORM SYSTEM. EXCEPT FOR THE SMALL POSSIBILITY OF
A DIRECT TSTM HIT...THE BURN AREAS SHOULD NOT BE TOO THREATENED BY
THIS SYSTEM. SNOW LEVELS WILL BE RATHER LOW WITH THIS COLD SYSTEM
THEY WILL START OUT AT 5000 FEET BUT WILL QUICKLY DROP TO 4000 FEET
AND THEN DOWN TO NEAR 3000 FEET BY MID MORNING WEDNESDAY.
.LONG TERM (THU-SUN)...
OUT SOON
&&
.AVIATION...
08/1200
KLAX AND KBUR...HIGH CONFIDENCE IN THE CURRENT TAFS.
...NOTE...
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...RORKE
AVIATION...BRUNO
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 081142
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
342 AM PST MON FEB 8 2010
.DISCUSSION...AS OF 3:00 AM PST MONDAY...CONSIDERABLE LOW LEVEL
MOISTURE REMAINS IN PLACE ACROSS OUR FORECAST AREA THIS MORNING.
WIDESPREAD LOW CLOUDS HAVE FORMED FROM SAN MATEO AND CONTRA COSTA
COUNTIES SOUTHWARD AND PATCHES OF DENSE FOG HAVE DEVELOPED IN THE
NORTH BAY VALLEYS. NORTH BAY VALLEY FOG WILL LIKELY CLEAR BY MID
MORNING. HOWEVER...LOW CLOUDS ACROSS THE SOUTHERN TWO-THIRDS OF THE
DISTRICT WILL PROBABLY LINGER UNTIL LATE MORNING OR EVEN EARLY
AFTERNOON. THESE CLOUDS MAY KEEP TEMPERATURES FROM RISING OUT OF THE
MID 50S TODAY.
EARLY MORNING SATELLITE IMAGERY SHOWS A COMPACT AND COOL WEATHER
SYSTEM SPINNING OFF THE COAST OF THE PAC NW. THE MODELS ARE IN GOOD
AGREEMENT AND ALL DROP THIS SYSTEM TO THE SSE OVER THE NEXT
48 HOURS...TRACKING THE CENTER OF A COLD UPPER LOW ALONG THE
CALIFORNIA COAST FROM LATE TONIGHT THROUGH TUESDAY EVENING.
SHOWERS PROBABLY WONT GET STARTED ACROSS OUR AREA UNTIL LATE
THIS EVENING...AND MORE LIKELY AFTER MIDNIGHT TONIGHT. SHOWERS WILL
THEN BECOME MORE NUMEROUS ON TUESDAY MORNING AS THE UPPER LOW CENTER
TRACKS JUST TO THE WEST OF SAN FRANCISCO. THE AIRMASS WILL BECOME
UNSTABLE ON TUESDAY. THE NAM FORECASTS SFC-BASED CAPE OF NEARLY 300
J/KG JUST OFF THE MONTEREY COUNTY COAST AT 18Z TUESDAY. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE...AND SMALL HAIL IS LIKELY IN
HEAVIER SHOWERS. RAINFALL TOTALS THROUGH TUESDAY EVENING AS FORECAST
BY THE CNRFC ARE IN THE ONE-TENTH TO HALF INCH RANGE...WITH
HEAVIEST AMOUNTS IN THE SANTA CRUZ AND SANTA LUCIA MOUNTAIN RANGES.
BOTH THE NAM AND GFS FORECAST 1000-500 MB THICKNESS VALUES TO DROP
TO AROUND 531 DM ON TUESDAY...WHICH CORRESPONDS TO A SNOW LEVEL OF
BETWEEN 2000 AND 2500 FEET. AN INCH OR TWO OF SNOW MAY ACCUMULATE
ABOVE 2500 FEET IN THE MOUNTAINS FROM SANTA CRUZ COUNTY SOUTH ON
TUESDAY. THE HIGHER END OF THAT RANGE WILL LIKELY BE ABOVE 3000
FEET AND THUS NO SNOW ADVISORIES ARE ANTICIPATED.
SHOWERS WILL BEGIN TO TAPER OFF FROM N TO S ON TUESDAY AFTERNOON AND
MAY LINGER ACROSS MONTEREY AND SAN BENITO COUNTIES INTO TUESDAY
EVENING. A MUCH DRIER NORTHERLY FLOW WILL DEVELOP BY LATE TUESDAY
NIGHT AND CLEARING WILL OCCUR BY WEDNESDAY MORNING. DRY WEATHER IS
FORECAST ON WEDNESDAY AND WEDNESDAY NIGHT. THE NEXT WEATHER SYSTEM
APPEARS TO BE RATHER WEAK AND LIGHT TO MODERATE AMOUNTS OF RAIN MAY
FALL ACROSS OUR REGION BETWEEN LATE THURSDAY AND EARLY FRIDAY.
THE LATEST GFS AND ECWMF AGREE THAT THE UPCOMING WEEKEND WILL
PROBABLY BE DRY.
&&
.AVIATION...AS OF 3:42 AM MONDAY...THE LATEST IR SATELLITE IMAGE IS
SHOWING CONSIDERABLE LOW LEVEL CLOUDS MOVING ACROSS THE DISTRICT
UNDER MOIST NORTHWEST FLOW. LOW LEVEL CLOUDS ARE EXPECTED TO MIX OUT
BY LATE MORNING AS HIGH PRESSURE SLIDES EVER SO SLOWLY EAST. A LOW
PRESSURE SYSTEM WILL MOVE INTO THE AREA EARLY TUESDAY MORNING
BRINGING A SHOT OF RAIN TO THE TERMINALS TUESDAY MORNING.
VICINITY OF KSFO...MVFR CIGS BKN021 EXPECTED TO MIX OUT BY 1700 Z.
VFR WILL THEN PERSIST FOR THE REMAINDER OF THE DAY. WEST WINDS 5 TO
10 KT EXPECTED THROUGH THIS EVENING. RAIN AND MVFR TO RETURN BY
1600 Z TUESDAY.
KSFO BRIDGE APPROACH...SAME AS KSFO.
MRY BAY AREA TERMINALS...MVFR CIGS BKN025 EXPECTED TO MIX OUT BY 1730
Z. VFR WILL THEN PERSIST FOR THE REMAINDER OF THE DAY. GENERALLY WEST
WINDS 5 TO 10 KT EXPECTED THIS AFTERNOON THROUGH EVENING. MVFR
BKN020 WILL RETURN BY 0200 Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...ROUGH BAR...SF BAR.
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: LARRY
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KREV 081130 CCA
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
320 AM PST MON FEB 8 2010
.SHORT TERM...
ABUNDANT LOW LEVEL MOISTURE STILL HANGING AROUND THE WESTERN GREAT
BASIN THIS MORNING IN THE WAKE OF A DEPARTING UPPER LOW. SHORTWAVE
RIDGING WILL CONTINUE TO BUILD OVERHEAD...WITH WINDS ALOFT REALLY
DROPPING OFF. FOG FORECAST THIS MORNING IS LOOKING LESS LIKELY...DUE
TO THE LINGERING CLOUDS NOT ALLOWING THE SURFACE TO COOL OFF AND FOG
IN. WE ARE SEEING SOME OF THE CLOUDS BEGINNING TO BREAK UP EAST OF
RENO. FREEZING FOG HAS NOT DEVELOPED YET...BUT WITH A FEW MORE HOURS
OF DARKNESS LEFT THIS MORNING...WE COULD SEE SOME PATCHY FOG
DEVELOPMENT IN THE BASIN VALLEYS EAST OF RENO.
A QUICK MOVING COLD LOW WILL SLIDE DOWN THE PACIFIC COAST
TUESDAY...POTENTIALLY BRINGING THE NEXT ROUND OF SNOW TO THE AREA.
THIS STORM WILL PRETTY COLD...WITH SNOW LEVELS DOWN TO VALLEY
FLOORS. LATEST MODEL RUNS ARE IN MUCH BETTER AGREEMENT...WITH THE
LOW PRESSURE TRACKING DIRECTLY ALONG THE CALIFORNIA COAST. AS THE
LOW TRACKS ALONG WESTERN CA...DEFORMATION ZONE PRECIP WILL SETUP
ALONG THE EASTERN EDGE OF THE UPPER LOW. NAM-GFS ARE HINTING THAT
THIS AREA OF ENHANCED PRECIP WILL SETUP OVER EASTERN CA AND WESTERN
NV...BRINGING SNOW ACCUMULATIONS DOWN TO THE VALLEY FLOORS TUESDAY.
00Z ECMWF ALSO TRACKS THE LOW PRESSURE OVER COASTAL CA AS WELL...BUT
KEEPS THE DEFORMATION ZONE PRECIP ALONG THE SIERRA CREST AND WESTERN
SLOPES. TRACK OF THE UPPER WILL BE EXTREMELY IMPORTANT TO THE AMOUNT
OF QPF/SNOW AMOUNTS THAT WE SEE IN OUR AREA.
NORMALLY WITH AN OUTSIDE SLIDER REGIME...WOULD PREFER TO SEE THE
UPPER LOW TRACK FURTHER INLAND OVER THE COASTAL RANGES OF NORCAL OR
EVEN OVER THE CENTRAL VALLEY...SO THAT THE DEFORMATION ZONE SETS UP
OVER US. BUT WITH NAM-GFS CONTINUING TO SHOW SOME IMPRESSIVE
FRONTOGENESIS AND 6-12 HOURS OF STRONG DENDRITIC ZONE OMEGA/LIFT
OVER RENO-TAHOE ROUGHLY BETWEEN 4AM TO 4PM...WILL CONTINUE WITH THE
SNOWY FORECAST. WITH EACH PASSING MODEL RUN...CONFIDENCE CONTINUES
TO INCREASE WITH REGARD TO QPF VALUES ON OUR SIDE OF THE SIERRA.
INCREASED POPS/QPF FOR THE SIERRA ZONES TUES-TUES NIGHT. WENT AHEAD
WITH CATEGORICAL SNOW FOR MOST OF THE SIERRA AND INTO RENO-CARSON
ZONE WEST OF HIGHWAY 395. SHOULD SEE MORE SHOWERY PRECIP OUTSIDE OF
THESE AREAS. AS FOR SNOW AMOUNTS WE COULD GET UP TO A COUPLE INCHES
IN THE WESTERN NV VALLEYS TUESDAY...INCLUDING RENO-CARSON
CITY-MINDEN...WITH 2 TO 4 INCHES IN THE FOOTHILLS WEST OF HIGHWAY
395. FOR THE EASTERN SIERRA COULD SEE ANYWHERE FROM 3 TO 6 INCHES
FROM WESTERN LASSEN DOWN THROUGH TAHOE AND MONO COUNTY...UP TO 8
INCHES ALONG THE CREST. IF THE FORECAST CONTINUES ON THIS
TRACK...MAY SEE SOME WINTER STATEMENTS LATER TODAY. HOON
.LONG TERM...THURSDAY THROUGH SUNDAY...
THERE IS A BIT MORE CONFIDENCE IN MODEL SOLNS THIS WEEKEND AS THE
ECMWF HAS COME CLOSER IN LINE WITH THE GFS/GEFS/GEM WHICH SHOW TROF
THU NGT-FRI FOLLOWED BY RIDGING THIS WEEKEND. ONE DIFFERENCE THAT
REMAINS IS HOW FAST TO PUSH THE FRI SYST EWD AS THE GFS IS MORE
CLOSED WITH FEATURE AND SLOWER THAN THE ECMWF TO ADVANCE IT EWD. THE
DETERMINISTIC ECMWF IS AT THE FAST SIDE OF THE ENVELOPE OF SOLNS AND
THUS THE FCST WAS KEPT CLOSER TO THE SLOWER GFS. HIGHEST POPS THU
NGT-FRI WERE TAPERED FROM N-S FRI NGT AND THEN DRIED OUT SAT-SUN AS
THERE IS NOW GOOD CONSENSUS FOR RDG. TEMPS NR OR SLGTLY BELOW NORMAL
THU-FRI ARE EXPECTED TO WARM SOME OVR THE WEEKEND ALTHOUGH PERIODS
OF MID-HI CLOUDS MAY MITIGATE THE POTENTIAL A BIT. HOHMANN
&&
.AVIATION...
FZFG BECOMING LESS A POTENTIAL THIS MRNG AS EXTENSIVE CLOUD COVER
HAS BEEN SLOW TO BREAK. LATEST SATELLITE PICTURES DID SHOW THINNING
AND EROSION OF THIS CLOUD DECK BUT IT WL NOT BE IN TIME TO ALLOW FOR
FOG DEVELOPMENT AT KRNO. LIFR CLOUD DECK HAS DEVELOPED AT KTRK WHERE
CLOUDS WERE THINNING ON WEST END AND THIS MAY LOWER FURTHER DURING
THE MRNG. SO WL CONT TO MENTION FZFG FOR KTRK AND KEEP IT THRU ABOUT
17Z. VFR ALL AREAS THIS AFTN/EVENING. NEXT SYST WL DROP DOWN THE W
COAST BEGINNING TNGT AND CONTG TUE WITH INCRG SNOW SHOWERS AND A
RETURN TO CIG/VSBY RESTRICTIONS INCLUDING MT OBSCUREMENT. CONDS WL
DETERIORATE 06Z-12Z AT KTVL/KTRK SITES WITH OCNL MVFR FLGT RULES IN
SNOW SHOWERS TUE AT KRNO AND WRN NV VLYS. ACCUMULATING SNOW IS
LIKELY AT SIERRA TAF SITES BUT UNLIKELY AT KRNO DUE TO TIMING OF
STORM DURING DAYLIGHT HOURS AND LIGHTER NATURE OF SNOW SHOWERS EAST
OF THE SIERRA. IF ONE OF THE MORE ISOLD HEAVIER BANDS MOVES ACRS THE
KRNO TERMINAL THEN SOME ACCUMULATION WOULD BE POSSIBLE BUT
SHORTLIVED. HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS65 KREV 081126
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
320 AM PST MON FEB 8 2010
.SHORT TERM...
ABUNDANT LOW LEVEL MOISTURE STILL HANGING AROUND THE WESTERN GREAT
BASIN THIS MORNING IN THE WAKE OF A DEPARTING UPPER LOW. SHORTWAVE
RIDGING WILL CONTINUE TO BUILD OVERHEAD...WITH WINDS ALOFT REALLY
DROPPING OFF. FOG FORECAST THIS MORNING IS LOOKING LESS LIKELY...DUE
TO THE LINGERING CLOUDS NOT ALLOWING THE SURFACE TO COOL OFF AND FOG
IN. WE ARE SEEING SOME OF THE CLOUDS BEGINNING TO BREAK UP EAST OF
RENO. FREEZING FOG HAS NOT DEVELOPED YET...BUT WITH A FEW MORE HOURS
OF DARKNESS LEFT THIS MORNING...WE COULD SEE SOME PATCHY FOG
DEVELOPMENT IN THE BASIN VALLEYS EAST OF RENO THIS MORNING.
A QUICK MOVING COLD LOW WILL SLIDE DOWN THE PACIFIC COAST
TUESDAY...POTENTIALLY BRINGING THE NEXT ROUND OF SNOW TO THE AREA.
THIS STORM WILL PRETTY COLD...WITH SNOW LEVELS DOWN TO VALLEY
FLOORS. LATEST MODEL RUNS ARE IN MUCH BETTER AGREEMENT...WITH THE
LOW PRESSURE TRACKING DIRECTLY ALONG THE CALIFORNIA COAST. AS THE
LOW TRACKS ALONG WESTERN CA...DEFORMATION ZONE PRECIP WILL SETUP
ALONG THE EASTERN EDGE OF THE UPPER LOW. NAM-GFS ARE HINTING THAT
THIS AREA OF ENHANCED PRECIP WILL SETUP OVER EASTERN CA AND WESTERN
NV...BRINGING SNOW ACCUMULATIONS DOWN TO THE VALLEY FLOORS TUESDAY.
00Z ECMWF ALSO TRACKS THE LOW PRESSURE OVER COASTAL CA AS WELL...BUT
KEEPS THE DEFORMATION ZONE PRECIP ALONG THE SIERRA CREST AND WESTERN
SLOPES. TRACK OF THE UPPER WILL BE EXTREMELY IMPORTANT TO THE AMOUNT
OF QPF/SNOW AMOUNTS THAT WE SEE IN OUR AREA.
NORMALLY WITH AN OUTSIDE SLIDER REGIME...WOULD PREFER TO SEE THE
UPPER LOW TRACK FURTHER INLAND OVER THE COASTAL RANGES OF NORCAL OR
EVEN OVER THE CENTRAL VALLEY...SO THAT THE DEFORMATION ZONE SETS UP
OVER US. BUT WITH NAM-GFS CONTINUING TO SHOW SOME IMPRESSIVE
FRONTOGENESIS AND 6-12 HOURS OF STRONG DENDRITIC ZONE OMEGA/LIFT
OVER RENO-TAHOE ROUGHLY BETWEEN 4AM TO 4PM...WILL CONTINUE WITH THE
SNOWY FORECAST. WITH EACH PASSING MODEL RUN...CONFIDENCE CONTINUES
TO INCREASE WITH REGARD TO QPF VALUES ON OUR SIDE OF THE SIERRA.
INCREASED POPS/QPF FOR THE SIERRA ZONES TUES-TUES NIGHT. WENT AHEAD
WITH CATEGORICAL SNOW FOR MOST OF THE SIERRA AND INTO RENO-CARSON
ZONE WEST OF HIGHWAY 395. SHOULD SEE MORE SHOWERY PRECIP OUTSIDE OF
THESE AREAS. AS FOR SNOW AMOUNTS WE COULD GET UP TO A COUPLE INCHES
IN THE WESTERN NV VALLEYS TUESDAY...INCLUDING RENO-CARSON
CITY-MINDEN...WITH 2 TO 4 INCHES IN THE FOOTHILLS WEST OF HIGHWAY
395. FOR THE EASTERN SIERRA COULD SEE ANYWHERE FROM 3 TO 6 INCHES
FROM WESTERN LASSEN DOWN THROUGH TAHOE AND MONO COUNTY...UP TO 8
INCHES ALONG THE CREST. IF THE FORECAST CONTINUES ON THIS
TRACK...MAY SEE SOME WINTER STATEMENTS LATER TODAY. HOON
.LONG TERM...THURSDAY THROUGH SUNDAY...
THERE IS A BIT MORE CONFIDENCE IN MODEL SOLNS THIS WEEKEND AS THE
ECMWF HAS COME CLOSER IN LINE WITH THE GFS/GEFS/GEM WHICH SHOW TROF
THU NGT-FRI FOLLOWED BY RIDGING THIS WEEKEND. ONE DIFFERENCE THAT
REMAINS IS HOW FAST TO PUSH THE FRI SYST EWD AS THE GFS IS MORE
CLOSED WITH FEATURE AND SLOWER THAN THE ECMWF TO ADVANCE IT EWD. THE
DETERMINISTIC ECMWF IS AT THE FAST SIDE OF THE ENVELOPE OF SOLNS AND
THUS THE FCST WAS KEPT CLOSER TO THE SLOWER GFS. HIGHEST POPS THU
NGT-FRI WERE TAPERED FROM N-S FRI NGT AND THEN DRIED OUT SAT-SUN AS
THERE IS NOW GOOD CONSENSUS FOR RDG. TEMPS NR OR SLGTLY BELOW NORMAL
THU-FRI ARE EXPECTED TO WARM SOME OVR THE WEEKEND ALTHOUGH PERIODS
OF MID-HI CLOUDS MAY MITIGATE THE POTENTIAL A BIT. HOHMANN
&&
.AVIATION...
FZFG BECOMING LESS A POTENTIAL THIS MRNG AS EXTENSIVE CLOUD COVER
HAS BEEN SLOW TO BREAK. LATEST SATELLITE PICTURES DID SHOW THINNING
AND EROSION OF THIS CLOUD DECK BUT IT WL NOT BE IN TIME TO ALLOW FOR
FOG DEVELOPMENT AT KRNO. LIFR CLOUD DECK HAS DEVELOPED AT KTRK WHERE
CLOUDS WERE THINNING ON WEST END AND THIS MAY LOWER FURTHER DURING
THE MRNG. SO WL CONT TO MENTION FZFG FOR KTRK AND KEEP IT THRU ABOUT
17Z. VFR ALL AREAS THIS AFTN/EVENING. NEXT SYST WL DROP DOWN THE W
COAST BEGINNING TNGT AND CONTG TUE WITH INCRG SNOW SHOWERS AND A
RETURN TO CIG/VSBY RESTRICTIONS INCLUDING MT OBSCUREMENT. CONDS WL
DETERIORATE 06Z-12Z AT KTVL/KTRK SITES WITH OCNL MVFR FLGT RULES IN
SNOW SHOWERS TUE AT KRNO AND WRN NV VLYS. ACCUMULATING SNOW IS
LIKELY AT SIERRA TAF SITES BUT UNLIKELY AT KRNO DUE TO TIMING OF
STORM DURING DAYLIGHT HOURS AND LIGHTER NATURE OF SNOW SHOWERS EAST
OF THE SIERRA. IF ONE OF THE MORE ISOLD HEAVIER BANDS MOVES ACRS THE
KRNO TERMINAL THEN SOME ACCUMULATION WOULD BE POSSIBLE BUT
SHORTLIVED. HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSGX 081028
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 AM PST MON FEB 8 2010
.SYNOPSIS...
DRY AND A LITTLE WARMER TODAY UNDER WEAK HIGH PRESSURE. A COLD LOW
PRESSURE SYSTEM FROM THE NORTHWEST WILL BRING MODERATE PRECIPITATION
AMOUNTS LATE TUESDAY INTO WEDNESDAY WITH LOW SNOW LEVELS AND A
CHANCE OF THUNDERSTORMS. WEAK HIGH PRESSURE FOR THURSDAY...THEN
ANOTHER CHANCE OF PRECIPITATION THURSDAY NIGHT AND FRIDAY WITH
WARMING AND DRYING FOR NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
WEAK HIGH PRESSURE WILL BRING DRYING AND MINOR WARMING TODAY.
FOR LATE TUESDAY THROUGH EARLY WEDNESDAY...A COLD CLOSED LOW
PRESSURE SYSTEM WILL MOVE SOUTHWARD ALONG THE WEST COAST...MOVING
INLAND ACROSS NORTHERN BAJA AND FAR SOUTHERN CALIFORNIA WEDNESDAY.
THE CURRENT TRACK WOULD BRING THE COLDEST MID LEVEL AIR ACROSS
SOUTHWEST CALIFORNIA LATE TUESDAY NIGHT AND EARLY WEDNESDAY.
LIGHT PRECIPITATION MAY DEVELOP IN ADVANCE OF THE SYSTEM DURING THE
DAY TUESDAY...MAINLY OVER NORTHWEST AREAS. A PERIOD OF MODERATE
PRECIPITATION IS EXPECTED FOR MOST AREAS TUESDAY NIGHT WITH SHOWERS
LINGERING INTO WEDNESDAY. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS
TUESDAY NIGHT THROUGH WEDNESDAY MORNING AS VERY COLD MID LEVEL AIR
DESTABILIZES THE ATMOSPHERE. SNOW LEVELS WILL ALSO BE QUITE
LOW...LOWERING TO 3000 TO 3500 FEET LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING. THIS WOULD BRING THE POSSIBILITY OF SNOWFALL TO
PORTIONS OF THE UPPER DESERTS.
PRELIMINARY AMOUNTS FOR NORTHERN AREAS ARE ONE HALF TO ONE INCH AT
THE COAST TO 1.5 TO 2.5 INCHES ON THE COASTAL SLOPES. FOR SOUTHERN
AREAS...AMOUNTS RANGING FROM AROUND ONE HALF TO THREE QUARTERS OF AN
INCH AT THE COAST TO 1 TO 2 INCHES ON THE COASTAL SLOPES. GENERALLY
ONE QUARTER TO ONE HALF INCH FOR THE UPPER DESERTS AND ONE QUARTER
INCH OR LESS FOR THE LOWER DESERTS.
PERIODS OF HIGH INTENSITY PRECIPITATION ARE POSSIBLE TUESDAY NIGHT
AND EARLY WEDNESDAY WHICH COULD INCREASE THE RUNOFF AND FLOODING
POTENTIAL...ESPECIALLY FOR NORTHERN AREAS NEARLY SATURATED FROM
RAINFALL FRIDAY NIGHT AND SATURDAY.
&&
.LONG TERM (THURSDAY THROUGH SUNDAY)...
YET ANOTHER TROUGH OF LOW PRESSURE COULD BRING A CHANCE OF
PRECIPITATION FOR THURSDAY NIGHT AND FRIDAY WITH THE MORE CLOSED AND
WESTWARD SOLUTIONS OF THE GFS AND DGEX BETTER FITTING THE DOMINANT
PATTERN AND FAVORED OVER THE ECMWF. CLOSED LOW PRESSURE LINGERING
OVER ARIZONA WOULD SLOW WARMING FOR SATURDAY...WITH GREATER WARMING
TO NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES FOR SUNDAY AND MONDAY.
&&
.AVIATION...
081000Z...GENERAL VFR CONDITIONS TODAY. A MODESTLY DEEP MOIST LAYER
WILL RESULT IN A SCATTERED TO LOCALLY BROKEN CLOUDS BTWN FL030-050
FM 19Z-23Z.
&&
.MARINE...
WIND: OUTER WATERS WINDS WERE 10-15 KTS EARLY THIS MORNING AND WILL
SUBSIDE THROUGH EARLY AFTERNOON.
SWELL: THE NSI OUTER BUOY AND THE TANNER BANK BUOY WERE STILL
REPORTING A 10-12 FOOT W SWELL AT 09Z. INNER BUOYS WERE REPORTING
6-8 FOOT SWELLS. THIS W SWELL WILL CONTINUE TO SLOWLY DECREASE TODAY
AND TONIGHT.
A HIGH SURF ADVISORY IS IN EFFECT FOR SAN DIEGO COUNTY THROUGH 10 AM
THIS MORNING.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 10 AM PST THIS MORNING FOR SAN DIEGO
COUNTY COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...MOEDE
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
000
FXUS65 KPSR 081000 AAA
AFDPSR
AREA FORECAST DISCUSSION...UPDATED SYNOPSIS
NATIONAL WEATHER SERVICE PHOENIX AZ
300 AM MST MON FEB 8 2010
.SYNOPSIS...
PARTLY CLOUDY SKIES AND SEASONABLE TEMPERATURES CAN BE EXPECTED
THROUGH TUESDAY. BY WEDNESDAY A QUICK MOVING LOW PRESSURE SYSTEM
WILL DROP OUT OF CALIFORNIA AND MOVE ACROSS SOUTHERN ARIZONA. THIS
WILL BRING CHANCES FOR RAIN AND SNOW SHOWERS TO MOST OF THE REGION.
HIGH PRESSURE WILL RETURN THURSDAY LEADING TO A MORE SUNSHINE ALONG
WITH WARMING TEMPERATURES HEADING INTO THE WEEKEND.
&&
.DISCUSSION...
RADAR ECHOES HAVE SUBSIDED THIS MORNING AS THE FINAL VORT MAX
ROTATING AROUND THE CLOSED LOW NEAR THE FOUR CORNERS EXITS OUR CWA.
H5 HEIGHTS WILL BE INCREASING TODAY INTO TUESDAY ALLOWING A DRY
FORECAST TO PREVAIL.
NEXT SHORT WAVE TROUGH...CURRENTLY APPROACHING THE PAC NW
COAST...WILL IMPACT OUR CWA BEGINNING LATE TUESDAY AND CONTINUING
THROUGH EARLY THURSDAY. OPERATIONAL AND ENSEMBLE MODELS ARE
GENERALLY IN GOOD AGREEMENT WITH THE TRACK AND INTENSITY OF THIS LOW
THOUGH THERE ARE DIFFERENCES IN THE DETAILS. A STRONG H25
SUBTROPICAL JET WILL BE DEVELOPING MONDAY AND TUESDAY ROUGHLY
STRETCHING FROM AZ TO FL. THE H5 LOW WILL TAKE A TRAJECTORY
PARALLELING THE CA COAST - NOT EXACTLY OPTIMAL FOR INGESTING MOIST
AIR FROM THE SOUTH. STRONG HEIGHT FALLS IN EXCESS OF 100M WILL MOVE
INTO OUR WESTERN CWA AROUND 12Z WED. JET CIRCULATION WILL DEVELOP
WITH LOW LEVEL WINDS OF 30KTS FROM THE SOUTH...NOT VERY STRONG. WHEN
COUPLED WITH FORECAST MIXING RATIOS IN THE LOW LEVELS OF ONLY 3-4
G/KG THAT YIELDS MOISTURE ADVECTION VALUES OF 50 GM/KGS AT BEST
/VALUES OF 100 OR HIGHER WOULD BE SOMETHING TO GET EXCITED ABOUT/.
THE LOW CONTINUES TO DROP THROUGH THE CENTER OF OUR CWA DURING THE
DAY WED. THOUGH THE HEIGHT FALLS WEAKEN WITH TIME THE MID-LEVELS
WILL BE COOLING CONSIDERABLY /H7 TEMPS NEARING -12 DEG C/ AND
COUPLED WITH THE TIME OF DAY I EXPECT WE/LL SEE A LINE OF CONVECTION
DEVELOP WITH THE INCOMING LOW. THUS TSTMS WERE ADDED TO THE
FORECAST. EVEN THOUGH THE SYSTEM DOES HAVE SOME FAVORABLE FORCING
WITH IT /PREVIOUSLY MENTIONED AND GOOD-VERTICALLY CORRELATED QG
CONVERGENCE/ THE LACK OF MOISTURE STOPS ME FROM RAISING POPS MUCH
HIGHER THEN WAS CURRENTLY FORECAST. IT APPEARS THAT THIS SYSTEM
WON/T DIP INTO THE SUBTROPICAL JET MOISTURE UNTIL IT IS MAINLY SE OF
OUR FORECAST AREA. WE/LL MONITOR THAT CRUCIAL ASPECT AS THIS
STORM...SHOULD IT APPEAR THAT MOISTURE WILL BE MORE READILY
AVAILABLE THAN CURRENTLY THOUGHT PRECIP CHANCES WOULD EASILY GO UP.
NOT SURPRISINGLY...SNOW LEVELS WILL FALL FROM 5-6KFT AHEAD OF THE
SYSTEM TO AS LOW AS 4KFT AS THE COLD POOL PASSES BY. AT THIS TIME
THE LOW QPF AMOUNTS YIELD ONLY 1-2 INCHES OF SNOW FOR AREAS ABOVE
4KFT. BUT AGAIN...SHOULD MOISTURE LOOK MORE AVAILABLE SNOW AMOUNTS
WILL GO UP WHICH WOULD RAISE THE POSSIBILITY OF A WINTER WEATHER
ADVISORY.
LOW QUICKLY MOVES OUT EARLY THURSDAY. A STRONG SHORT WAVE RIDGE
BEHIND THE LOW SHOULD KEEP IT MOVING ALONG SO POPS WILL COME DOWN
PRETTY QUICK. VARYING MODEL SOLUTIONS BEYOND THOUGH SOME AGREEMENT
THERE WILL BE A TROUGH/LOW MOVING THROUGH THE GREAT BASIN OVER THE
WEEKEND. AT THIS TIME IT LOOKS LIKE IT WILL BE FAR ENOUGH NORTH TO
NOT POSE A SIGNIFICANT THREAT TO OUR AREA.
&&
.AVIATION...
KPHX AND KIWA...
THROUGH 09Z MON...SCT TO BKN CLOUDS AOA 9 THSD MSL ARE EXPECTED...
ALONG WITH ISOLATED LIGHT SHOWERS. BETWEEN 09Z MON AND 23Z MON...
SCT CLDS NEAR 9 THSD MSL. LIGHT WIND.
KIPL AND KBLH...
MOSTLY CLEAR SKIES EXPECTED THROUGH 10Z MON...WITH THE EXCEPTION OF
SCT TO BKN CLOUDS NEAR 8 THSD MSL AT KBLH. AFTER 10Z AND CONTINUING
THROUGH 23Z MON...CLEAR SKIES AND LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A BRIEF INTERLUDE OF DRIER WEATHER THROUGH TUESDAY. ANOTHER PACIFIC
LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION WEDNESDAY INTO
THURSDAY...BRINGING RAIN AND MOUNTAIN SNOW SHOWERS TO PORTIONS OF
SOUTHEAST CALIFORNIA AND SOUTH-CENTRAL ARIZONA. OVERALL...EXPECT
COOLER TEMPERATURES...ELEVATED HUMIDITY LEVELS...AND SOME LOCALLY
GUSTY WINDS ASSOCIATED WITH THE STRONGER STORMS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL TO 5 PM MST SUNDAY AZZ024.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...MEYERS
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