[top]
000
FXUS66 KLOX 040126
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
620 PM PDT FRI JUL 3 2009
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
SEASONAL STRONG HIGH PRESSURE CONTINUES FOR SOUTHWEST UNITED STATES
AND CALIFORNIA THROUGH MONDAY...ALONG WITH WARM TEMPERATURES AND LOW
HUMIDITIES INLAND. LOOK FOR SLIGHTLY COOLER BEGINNING TUESDAY AS THE
RIDGE OF HIGH PRESSURE MOVES EAST. COAST WILL CONTINUE COOLER WITH
AN ONGOING MARINE LAYER.
&&
.SHORT TERM (TODAY-MON)...TODAY VERY SIMILAR TO THE LAST SEVERAL
DAYS. MARINE LYR STICKING CLOSE TO THE BEACHES IN MANY AREAS,
DAYTIME TEMPS WITHIN 2 OR 3 DEGREES IN MOST LOCATIONS, AND NO
AFTERNOON CONVECTION IN THE MTNS AND DESERTS. REALLY DON`T SEE MUCH
CHANGE IN THIS PATTERN THROUGH THE HOLIDAY WEEKEND. PERHAPS AN EVER
SO SLIGHT DECREASE IN MARINE LYR DEPTH TONIGHT AND A DEGREE OR TWO
WARMER. OTHERWISE, WHAT YOU`VE SEEN IS WHAT YOU WILL GET.
.LONG TERM (TUE-FRI)...MODELS HAVE BEEN ADVERTISING A TROF ALONG THE
COAST FOR NEXT WEEK, AND WHILE THIS IS STILL THE CASE, 12Z GFS AND
ECMWF WERE BOTH WEAKER WITH IT, ESPECIALLY THE ECMWF, WITH MORE
EMPHASIS PLACED ON THE UPPER HIGH OVER SRN AZ/NRN MX. AS A RESULT,
MOS GUIDANCE HIGHS FOR NEXT WEEK WERE 3-5 DEGREES WARMER THAN
EARLIER RUNS. NUDGED UP HIGHS SLIGHTLY FOR NEXT WEEK, BUT OTHERWISE
LEFT THE FORECAST LARGELY UNCHANGED. THE TROF WILL CERTAINLY
MAINTAIN A DECENT MARINE LYR PRESENCE AT THE COAST WITH SOME INLAND
PUSH EACH NIGHT. DRY WEST/SOUTHWEST FLOW ALOFT WILL KEEP ALL
CONVECTION WELL TO THE EAST. OVERALL A VERY DULL FORECAST, BUT VERY
PLEASANT CONDITIONS ACROSS OUR AREA.
&&
.AVIATION...04/0100Z.
MARINE LAYER NEAR 1200 FT DEEP THIS AFTERNOON. EXPECT MOSTLY VFR
CONDITIONS THIS AFTERNOON...EXCEPT PESKY STRATUS AFFECTING KLAX
THROUGH 02Z. SOME EARLIER THEN EXPECTED STRATUS NOW MOVING INTO THE
CENTRAL COAST. GOOD CONFIDENCE FOR IFR CIGS TO AFFECT KSMX BY 02-04Z
AND KSBY A FEW HOURS LATER. MODERATE CONFIDENCE FOR IFR/MVFR CIGS TO
AFFECT COASTAL SITES IN LA/VTU/SBA COUNTIES BETWEEN 07-09Z. LOW
CONFIDENCE FOR CIGS TO AFFECT KBUR/KVNY OVERNIGHT...IF IT
DOES...AFTER 11Z AND SHORT LIVED. SKIES ACROSS COASTAL AREAS SHOULD
BURNOFF BY 18Z IN MOST AREAS.
KLAX...PATCHY IFR CIGS AFFECTING RUNWAYS THROUGH 02Z...THEN GOOD
CONFIDENCE FOR VFR CONDS THROUGH 6Z...THEN GOOD CONFIDENCE FOR
IFR/MVFR CIGS BETWEEN 08-09Z TONIGHT AND PERSIST THROUGH 16-18Z THEN
BECOME VFR SATURDAY AFTERNOON.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH SATURDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...WOFFORD
AVIATION...KAPLAN
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
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000
FXUS66 KMTR 032337
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
236 PM PDT FRI JUL 3 2009
.DISCUSSION...AS OF 2:35 PM PDT FRIDAY...SO FAR A VERY PLEASANT DAY
AROUND THE SAN FRANCISCO AND MONTEREY BAY AREA. SIMILAR TO YESTERDAY
THE STRATUS CLEARED OUT AND AFTERNOON TEMPERATURES HAVE MADE IT INTO
THE MID 60S TO LOWER 70S ALONG THE COAST AND MID 70S TO LOWER 90S
INLAND. A QUICK GLIMPSE AT THE VISIBLE SATELLITE IMAGE DOES SHOW
STRATUS JUST OFF OF THE COAST AND THE FORT ORD PROFILER IS
INDICATING THAT THE MARINE LAYER IS ABOUT 1600 FEET DEEP.
THEREFORE...EXPECT STRATUS TO RETURN TO THE AREA ONCE AGAIN TONIGHT.
TOMORROW...INDEPENDENCE DAY...WILL AGAIN BE PLEASANT WITH SIMILAR
CONDITIONS EXPECTED.
A COOL DOWN IS STILL EXPECTED BEGINNING EARLY NEXT WEEK. THIS IS
DUE TO A TROUGH OF LOW PRESSURE WHICH IS BEING WELL ADVERTISED BY
BOTH THE 1200 UTC ECMWF AND OPERATIONAL GFS. THE TROUGH IS EXPECTED
TO REACH THE PACIFIC NORTHWEST BY MONDAY MORNING AND 500MB HEIGHTS
WILL BEGIN TO FALL ACROSS THE CWA. THE ECMWF SEEMS TO BE COMING
INTO BETTER AGREEMENT WITH THE GFS ON THE MAGNITUDE OF THE LOW
HOWEVER THE GFS IS STILL RUNNING ABOUT 3 TO 5 DM LOWER AT 500MB.
WITH THE GFS ADVERTISING 850 TEMPERATURES TO DROP TO 10 DEGREES
CELSIUS TUESDAY MORNING OVER THE SAN FRANCISCO BAY AREA EXPECT
SURFACE TEMPERATURES OF ABOUT 68 IN SAN FRANCISCO AND 74 IN SAN JOSE.
ALTHOUGH...THE TWO MODELS ARE DIFFERING ON THE OF MAGNITUDE OF THIS
TROUGH BOTH SOLUTIONS ARE RATHER STRONG FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 4:30 PM PDT FRIDAY...AFTERNOON SATELLITE
IMAGERY SHOWS MORE LOW CLOUDS ALONG THE COAST THAN YESTERDAY.
ALTHOUGH PRESSURE GRADIENTS AND MARINE LAYER IS BASICALLY
UNCHANGED FROM YESTERDAY...THE PRESENCE OF MORE LOW CLOUDS AT THE
COAST THIS AFTERNOON SUGGESTS THE LOW CLOUDS WILL MOVE IN A LITTLE
EARLIER THAN YESTERDAY. CONFIDENCE IS LOW BECAUSE THE MODELS ARE
SUGGESTING LESS LOW CLOUDS PENETRATING INLAND TONIGHT DUE TO WEAK
OFFSHORE FLOW. AT THE PRESENT TIME THIS OFFSHORE FLOW HAS NOT BEEN
OBSERVED. IRREGARDLESS VFR CONDITIONS ARE EXPECTED THROUGH THE
AIRPORT EVENING RUSH HOUR.
VICINITY OF KSFO...VFR CONDITIONS THROUGH THE AIRPORT EVENING RUSH
HOUR WITH LOW CEILINGS EXPECTED AFTER 06Z. BASES NEAR 1000 FEET.
GUSTS TO 25 KT THROUGH EARLY EVENING.
KSFO BRIDGE APPROACH...VFR CONDITIONS THROUGH THE AIRPORT EVENING
RUSH HOUR WITH LOW CEILINGS EXPECTED AFTER 06Z. BASES NEAR 1000
FEET.
MONTEREY BAY TERMINALS...STRATUS FILLING IN OVER SOUTHERN MRY BAY
AND SHOULD MOVE INTO MRY EARLY TONIGHT AROUND 03Z WHILE SNS
SHOULD HAVE CEILINGS BY 06Z. BASES NEAR 1000 FEET.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: SSA/W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
[top]
000
FXUS65 KPSR 032238
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
330 PM MST FRI JUL 3 2009
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
LATEST RUC ANALYSIS PLACES THE MAIN 500 MB ANTICYCLONE ACROSS TX BUT
WITH A RIDGE AXIS EXTENDING BACK INTO SW AZ. AFTERNOON SAT/RADAR
TRENDS SHOW SCATTERED CONVECTION NORTH OF THE CWA HAVING A HARD TIME
MOVING AGAINST THE ANTICYCLONIC FLOW AND INTO THE LOWER ELEVATIONS.
ATMOSPHERE REMAINS PRIMED ACROSS THE PHOENIX METRO AREA...THOUGH IT
WILL TAKE AN OUTFLOW BOUNDARY TO REALIZE THE INSTABILITY.
LATEST GFS SUGGESTS A VORT MAX LIFTING NORTH OUT OF SONORA WILL
PRODUCE THUNDERSTORMS FIRST ACROSS SE AZ...BEFORE PROPAGATING
TOWARDS THE SOUTHEASTERN CWA THIS EVENING. RAIN CHANCES WILL BE
HIGHEST IN THE PHOENIX METRO AREA THIS EVENING AS THE FLOW VEERS
AROUND THE RIDGE...ADDITIONAL ACTIVITY DEVELOPS SOUTH AND EAST OF
THE AREA AND THE LOW LEVEL MOISTURE CONVERGENCE IS MAXIMIZED.
HOWEVER...OFFICIAL FORECAST (20% FOR PHOENIX) IS GENERALLY BELOW
LATEST MAVS AND CLOSER TO MOS RELIABILITY VALUES.
PREVIOUS DISCUSSION...
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
CU AND TCU BUILDING OVER MOUNTAINS AT 17Z PER 88D AND PIREPS...IN
RATHER MOIST ENVIRONMENT. IN FACT...YOUR LATEST PHOENIX SOUNDING HAD
1.69 INCHES OF P/WATER WITH A WEAK STABLE LAYER AT 20 THSD FEET.
CONVECTION IS UNDERWAY...AND STEERING FLOW REMAINS IDEAL FOR ISOLD
ACTIVITY TO DRIFT INTO THE AREA AFTER 00Z. OUTFLOW WINDS COULD
BE STRONG ENUF TO KICK UP DUST BUT STILL NOT CONFIDENT TOO SHOW THAT
HAZARD IN 18Z TAFS. FOR THE 4TH...WITH A POSSIBLE INCREASE IN
MOISTURE WE COULD SEE MORE CLOUDS BTWN 9 AND 12 THD FT.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS UNTIL LATE TONIGHT WHEN
SOUTHERLY WINDS KICK UP AND A GULF SURGE ARRIVES FOR YOUR 4TH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/ESTLE
AVIATION...SIPPLE
FIRE WEATHER...INIGUEZ
[top]
000
FXUS65 KREV 032235
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
335 PM PDT FRI JUL 3 2009
.SHORT TERM...
ISOLD CONVECTION HAS DEVELOPED ACROSS NWRN NV THIS AFTERNOON NORTH
OF LOVELOCK-GERLACH LINE ADN IN ERN CHURCHILL COUNTY ALTHOUGH MID
LEVEL CAP HAS LIMITED CELL INTENSITY. THE WEAK SHORTWAVE OVER NRN
CA WHICH HAS BEEN ABLE TO TRIGGER THIS CONVECTION WILL FINALLY
EJECT NEWD OVERNIGHT. A FEW SHOWERS MAY SURVIVE IN FAR NWRN NV THRU
LATE TONIGHT UNTIL THIS SYSTEM COMPLETELY CLEARS THE REGION.
DRY WEATHER WILL PREVAIL FOR THE HOLIDAY WEEKEND INTO EARLY NEXT
WEEK AS SW FLOW ALOFT SETS UP OVER THE REGION. THERE IS A REMOTE
CHANCE THAT A BRIEF TSTM CELL MAY DEVELOP IN FAR NWRN NV/SURPRISE
VLY NORTH OF CEDARVILLE LATE SAT AFTN AND MOVE QUICKLY NORTH OF
THE OREGON BORDER AS SOME LEFTOVER INSTBY IS INDICATED IN THIS
AREA. HOWEVER...THIS POTENTIAL IS NOT SIGNIFICANT ENOUGH TO
INCLUDE IN THE FORECAST AT THIS TIME. MID LEVEL MOISTURE WILL ALSO
GENERATE SCT CUMULUS BUILDUPS OVER PARTS OF MINERAL-MONO
COUNTIES...BUT STRONGER MID LEVEL CAP WILL PREVENT ANY MEANINGFUL
VERTICAL GROWTH FROM THESE CLOUDS.
WINDS ON SATURDAY ARE EXPECTED TO BE PRIMARILY LATE DAY ZEPHYR
TYPE BREEZES WITH GUSTS 25-30 MPH LASTING UNTIL AROUND 10 PM IN
THE RENO-SPARKS-CARSON AREAS BUT DIMINISHING BY DUSK IN THE TAHOE
BASIN. AS TROF APPROACHES THE NWRN US BY SUNDAY...WINDS WILL
INCREASE SLIGHTLY WITH GUSTS UP TO 35 MPH. TEMPS WILL REMAIN A FEW
DEGREES ABOVE NORMAL THRU THIS WEEKEND WITH MOST VALLEYS REACHING
THE 90S...AS COOLING IS NOT EXPECTED TO REACH THE REGION UNTIL SUN
NIGHT AND MONDAY..BY MONDAY...LOWER 500 MB HEIGHTS WITH TIGHTER
PRESSURE GRADIENT WILL BRING A START TO A COOLING TREND AND ALSO
PRODUCE A FURTHER INCREASE IN WIND SPEEDS WITH SOME GUSTS NEAR 40
MPH. MJD
.LONG TERM...TUESDAY THROUGH FRIDAY...
NO MAJOR CHANGES TO LONG TERM FORECAST FOR NOW. GOOD AGREEMENT WITH
TROUGH OVER THE WEST COAST THOUGH THE MIDDLE OF NEXT WEEK...WITH DRY
AND STABLE SOUTHWEST FLOW ALOFT. WE WILL SEE A BIT OF COOLING OFF
TUES-WED AS THE A WEAK COOL FRONT MOVES OVER THE FORECAST
AREA...POSSIBLY EVEN A SLIGHT CHANCE OF SHOWERS IN THE NORTHERN
ZONES. BREEZY TO WINDY AFTN/EVE WINDS CAN BE EXPECTED THROUGH THE
LONG TERM WITH THE INCREASED PRESSURE/TEMPERATURE GRADIENT.
STRONG UPPER RIDGE WILL RETROGRADE AND BUILD INTO THE SOUTHWESTERN
STATES AS WE GO INTO NEXT WEEKEND...THU-SAT. EURO IS SHOWING A BIG
BUBBLE 599 DM HIGH OVER NEW MEXICO...WITH VALUES IN THE NEAR 590 DM
OVER CA/NV. THIS COULD MEAN TEMPS WELL ABOVE NORMAL. DIDN`T JUST ON
THE WAGON ALL THE WAY YET...BUT BEGAN TRENDING TEMPS UP AND HUMIDITY
DOWN FOR BIG RIDGE. GFS IS SHOWING A TROUGH BREAKING DOWN THE RIDGE
THU-FRI...BUT TEND TO BELIEVE THE STRONGER RIDGE OF THE EC DUE THE
MIDSUMMER TIMEFRAME. HOON
&&
.FIRE WEATHER...
ONLY ISOLD TSTM EXPECTED ACROSS NORTHERN/ERN THIRD OF AREA BEFORE
DRYING SW FLOW REALLY TAKES HOLD BY TOMORROW. EXPECT DAYTIME RH TO
DROP TO SINGLE DIGITS SUN IN WRN NV VALLEYS AND NEAR 10 PCT SIERRA
VALLEYS. WINDS WILL GRADUALLY INCREASE EACH DAY WITH A TYPICAL
ZEPHYR THIS EVENING AND SAT WITH AN ENHANCED ZEPHYR FOR SUN AS
POTENT TROUGH MOVES OFF THE PACNW COAST.
NORMALLY...SUN COULD BE A RED FLAG DAY...BUT FUELS ARE STILL
SOMEWHAT MARGINAL AFTER CALLS YESTERDAY TO LCL GACCS/FMO-S. RH
CRITERIA WILL BE HIT...BUT WITH WIND GUSTS ONLY PEAKING NEAR 30
MPH SUN...A MARGINAL EVENT...WILL LET IT GO GIVEN FUELS.
HOWEVER...STRONGER WINDS ARE EXPECTED MON AND TUE WITH RH AGAIN
5-10%. ATTM...ONE OF THE TWO DAYS WILL LIKELY SEE WIDESPREAD GUSTS
CLOSE TO 40 MPH AND WITH SUCH A POTENTIALLY STG EVENT...THE MARGINAL
FUELS ARE A BIT LESS OF A FACTOR. GFS SHOWS MON BEING THE STRONGEST
AND EC TUE THE STRONGEST. GIVEN UNCERTAINTY...WILL NOT GO WITH A
WATCH YET FOR MON...AND JUST KEEP AN EYE ON THINGS. FOR FIRE
MANAGERS OUT THERE WE HAVE NOT SPOKEN TO...WE WOULD APPRECIATE ANY
INPUT YOU HAVE ON CURRENT STATE OF FUELS IN YOUR AREA ESP IF OUR
CURRENT THINKING ABOVE CONCERNS YOU. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
[top]
000
FXUS66 KHNX 032210
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
310 PM PDT FRI JUL 3 2009
.DISCUSSION...INTERIOR CENTRAL CALIFORNIA REMAINS ON THE PERIPHERY
OF AN UPPER RIDGE OVER THE WESTERN US. THIS IS PRODUCING A DRY
SOUTHWESTERLY FLOW ACROSS THE REGION AND ONLY A FEW SMALL CU HAVE
BEEN NOTED OVER THE MOUNTAINS THIS AFTERNOON. TEMPERATURES ARE
GENERALLY RUNNING WITHIN PLUS OR MINUS A DEGREE OR SO OF THIS
TIME YESTERDAY AND HIGHS SHOULD AGAIN TOP OUT AROUND 4-8 DEGREES
ABOVE SEASONAL AVERAGES.
LITTLE CHANGE IN CONDITIONS IS EXPECTED THROUGH THE HOLIDAY
WEEKEND AS THE REGION REMAINS BETWEEN THE RIDGE AND A DEVELOPING
TROUGH OVER THE NORTHEAST PACIFIC. MODELS HAVE SOME DIFFERENCES IN
THEIR DEPICTION OF THE EVOLUTION OF THE TROUGH...THE GFS BEING A
BIT MORE AGGRESSIVE. A SOMEWHAT MIDDLE OF THE ROAD SOLUTION BEGINS
A COOLING TREND OVER THE DISTRICT BY MONDAY...DROPPING TEMPS TO
AROUND CLIMO AS HEIGHTS AND THICKNESSES DECREASE AND ONSHORE FLOW
INCREASES.
COOLING SHOULD CONTINUE THROUGH WEDNESDAY AS THE TROUGH MOVES
ONSHORE...WITH TEMPERATURES DROPPING TO A FEW DEGREES BELOW
SEASONAL NORMS. THURSDAY AND FRIDAY WILL THEN SEE TEMPERATURES
REWARMING TOWARD CLIMO AS THE UPPER RIDGE PUSHES INTO THE REGION.
NO SIGNIFICANT MOISTURE ACCOMPANIES THE APPROACHING TROUGH AND THE
FORECST REMAINS POP-FREE THROUGHOUT THE PERIOD.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA
INTERIOR THROUGH 12Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 3 2009... UNHEALTHY IN KERN COUNTY. UNHEALTHY FOR
SENSITIVE GROUPS IN FRESNO... KINGS... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JEB
AVN/FW...DCH
WEATHER.GOV/HANFORD
[top]
000
FXUS66 KEKA 032207
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
305 PM PDT FRI JUL 3 2009
.SYNOPSIS...A WEAK AREA OF LOW PRESSURE ALONG THE COAST WILL WEAKEN
AND SHIFT INLAND OVERNIGHT...WITH A SLIGHT CHANCE OF THUNDERSTORMS
ACROSS TRINITY AND EASTERN MENDOCINO COUNTIES COMING TO AN END.
ANOTHER SERIES OF DISTURBANCES WILL IMPACT THE REGION NEXT
WEEK...BRINGING MUCH COOLER TEMPERATURES TO INLAND LOCATIONS AND A
MIX OF CLOUDS AND SUNSHINE TO THE COAST.
&&
.DISCUSSION...THE MAIN FORECAST CONSIDERATIONS CONTINUE TO BE
THUNDERSTORM CHANCES THIS EVENING AND THE PATTERN EVOLUTION NEXT
WEEK.
VAPOR IMAGERY SHOWS A WEAK LOW PRESSURE AREA ALONG THE COAST AT
EARLY AFTERNOON...WITH CUMULUS STRUGGLING TO BUILD DUE TO A WEAKLY
CAPPED ENVIRONMENT AND DRIER WESTERLY FLOW MOVING INTO THE AREA. THE
BEST CHANCE FOR THUNDERSTORM DEVELOPMENT IS OVER THE YOLLA BOLLYS
AND ALONG THE MENDOCINO/LAKE/GLENN COUNTY BORDER. THUS...WE WILL
RETAIN THE MENTION OF ISOLATED THUNDER FOR THE EVENING HOURS ACROSS
TRINITY/EASTERN MENDOCINO COUNTIES. ALONG THE COAST...THE MARINE
INVERSION REMAINS STRONG AND THUS LITTLE CHANGE IN SENSIBLE WX IS
EXPECTED OVERNIGHT WITH LOW CLOUDS/FOG AND PERHAPS A LITTLE DRIZZLE.
INDEPENDENCE DAY WILL BRING LITTLE CHANGE IN THE SYNOPTIC SITUATION
ASIDE FROM CONVECTIVE PARAMETERS LOOKING EVEN LESS FAVORABLE...SO
WILL PRECLUDE THEM. WHILE SOME AFTERNOON CLEARING IS POSSIBLE ALONG
THE COAST...AN APPROACHING TROUGH WILL BEGIN TO DEEPEN THE MARINE
LAYER. SO...FOR EVENING FESTIVITIES...THE BEST ESTIMATION AT THIS
POINT CONTINUES TO BE FOR A LOW OVERCAST ALONG THE COAST WITH CLEAR
AND PLEASANT WX INLAND. A NUMBER OF IMPULSES DROP INTO THE OFFSHORE
TROUGH THROUGH THE EARLY AND MIDDLE PORTIONS OF NEXT WEEK...HELPING
TO STALL ITS EASTWARD PROGRESSION AND CARVE OUT A DEEPER SYSTEM.
CONVECTIVE PARAMETERS AT FACE VALUE ARE SURPRISINGLY LOW...AND WILL
ACCEPT THIS AS OF NOW...BUT THIS WILL NEED TO BE CAREFULLY MONITORED
AS THE COLD POOL ALOFT AND IMPROVED DYNAMICS MAKE THEIR WAY TOWARDS
THE NORTH STATE. IT IS LIKELY THAT THE BOUNDARY LAYER WILL COOL
ENOUGH TO WASH OUT THE MARINE INVERSION TO SOME EXTENT BY TUESDAY
NIGHT...BUT REMAINING MOISTURE WILL PROBABLY BE LIFTED TO FORM A
HAPHAZARD PATTERN OF STRATOCU EXTENDING INLAND FROM TIME TO TIME.
OTHERWISE...LOOK FOR UNSEASONABLY COOL WEATHER FOR INLAND AREAS WITH
HIGHS ONLY MANAGING THE 70S FOR OUR VALLEYS FOR TUESDAY AND
WEDNESDAY. BURGER
&&
.AVIATION...PER SATELLITE...LOW COASTAL CLOUDS AND FOG CONTINUE TO
SHROUD MUCH OF THE IMMEDIATE NORTH COAST. KEEPING WITH PERSISTENCE
OVER THE PAST FEW DAYS...EXPECT SOME PARTIAL CLEARING THROUGH EARLY
EVENING. ALTHOUGH MUCH OF THE STRATUS WILL PEEL BACK TO THE BEACHES
THROUGH LATE AFTERNOON...POCKETS OF IFR/LIFR CLOUDS WILL PERSIST
OVER THE BAYS...COVES AND INLETS. HIGH FIVE TO THE PREVIOUS
DISCUSSION THAT MVFR/IFR CONDITIONS NEAR THE COAST WILL AGAIN
PREDOMINATE AFTER SUNRISE...DROPPING INTO LIFR CATEGORY SOON
AFTERWARDS. VFR WILL PREVAIL INLAND WITH THE THREAT OF LATE
AFTERNOON...ISOLATED CONVECTION. ASHFORD
&&
.MARINE...LIGHT WINDS AND LOW SEAS WILL PREVAIL THROUGH THE WEEKEND
AS THE PRESSURE GRADIENT REMAINS WEEK. A LONG PERIOD S SWELL AND
SHORT PERIOD NW SWELL WILL PREVAIL THROUGH THE WEEKEND INTO EARLY
NEXT WEEK. A COLD FRONT WILL PUSH ACROSS THE WATERS MON WITH HIGH
PRESSURE BUILDING IN ITS WAKE. A TIGHTENING PRESSURE GRADIENT BEHIND
THE FRONT WILL RESULT IN INCREASING N WINDS AND BUILDING SEAS EARLY
NEXT WEEK. BC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
[top]
000
FXUS66 KSTO 032150
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
250 PM PDT FRI JUL 03 2009
.DISCUSSION...
UPPER LOW IS CROSSING THE NORTHWEST CAL COAST AND IS FORECAST TO
GRADUALLY FILL AS IT SLOWLY LIFTS ACROSS THE FAR NORTHERN INTERIOR
OVERNIGHT. SATELLITE IMAGERY SHOWING TCU OVER THE COASTAL RANGE BUT
NOTHING ON RADAR AS OF YET. STRONGER CELLS HAVE DEVELOPED OVER THE
LASSEN PARK/WESTERN PLUMAS AREAS WITH A STORM DEVELOPING JUST
SOUTHWEST OF CHESTER. THREAT OF ISOLATED SHOWERS OR THUNDERSTORMS
WILL BE POSSIBLE N OF A KUKI-KOVE-KRNO UNTIL SUNSET.
AFTERNOON TEMPS RUNNING NEAR TO SLIGHTLY COOLER THIS AFTERNOON AS
UPPER LOW IMPARTING SOME WEAK SYNOPTIC COOLING. DELTA BREEZE
SLIGHTLY WEAKER THAN 24 HOURS AGO BUT MARINE LAYER IS ABOUT 400 FEET
LOWER THAN YESTERDAY. WEAKER DELTA BREEZE FORECAST TONIGHT WILL
RESULT IN LESS LOW LEVEL CAA THROUGH DELTA INTO SOUTHERN SAC VALLEY.
DRIER SOUTHWESTERLY FLOW OVER ALL OF INTERIOR NORCAL SATURDAY WITH
NEAR TO SLIGHTLY WARMER TEMPS. ANOTHER LOW PRESSURE SYSTEM DEEPENS
IN THE EASTERN PACIFIC AND FORECAST TO LIFT ACROSS THE PAC NW SUN
INTO MONDAY AS LONG WAVE TROUGH BECOMES ESTABLISHED NEAR 130W. THIS
SETS UP COOLING TREND SUNDAY INTO WEDNESDAY WITH INCREASED ONSHORE
FLOW AND SYNOPTIC COOLING AS SERIES OF SHORT WAVES MOVE INTO PAC NW.
VALLEY TEMPS EXPECTED IN THE 80S MONDAY THROUGH THURSDAY OF NEXT
WEEK WITH 60S TO 70S IN THE HIGHER ELEVATIONS. ECMWF/GFS KEEP ANY
PRECIP WITH ASSOCIATED SHORT WAVES MAINLY ALONG THE FAR NW CAL COAST
AND NEAR THE ORCA BORDER NORTHWARD. PERIODS OF GUSTY SOUTHWEST WIND
THROUGH THE DELTA AND OVER HIGHER TERRAIN CAN BE EXPECTED NEXT WEEK
WITH PASSING SHORT WAVES.
PCH
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)...
COOLER THAN NORMAL TEMPERATURES ARE EXPECTED FOR MOST OF THE
EXTENDED PERIOD AS THE WEST COAST WILL BE UNDER THE INFLUENCE OF LOW
PRESSURE. BOTH THE GFS AND ECMWF AGREE WELL ON THE OVERALL PICTURE
WITH A LONGWAVE TROUGH CENTERED OVER THE PACIFIC NORTHWEST. THE MAIN
DIFFERENCE WILL BE HOW DEEP THE LOW WILL BE...AND HOW MUCH THAT WILL
INFLUENCE NORCAL`S TEMPERATURES. THE GFS PROGS LOWER HEIGHTS AND
THICKNESSES THAN THE ECMWF...WHICH WOULD TRANSLATE INTO SLIGHTLY
COOLER TEMPS. IN EITHER CASE...WE ARE CURRENTLY LOOKING AT
TEMPERATURES IN THE NEIGHBORHOOD OF 5 TO 10 DEGREES COOLER THAN
NORMAL FOR MUCH OF NEXT WEEK...AS THE UPPER TROUGH WILL BE SLOW TO
MOVE OUT.
&&
.AVIATION...VFR CONDITIONS EXPECTED THE NEXT 24 HOURS. CUMULUS
CLOUDS ARE BUILDING UP ALONG PORTIONS OF THE COASTAL RANGE...THE
NORTHERN INTERIOR MOUNTAINS...AND THE WESTERN SLOPES OF THE NORTHERN
SIERRA. A FEW SHOWERS AND/OR THUNDERSTORMS MAY FORM ALONG THE
COASTAL RANGE CREST AND TOWARDS LASSEN PARK. GENERALLY LIGHT WINDS
ARE EXPECTED EXCEPT WIND GUSTS TO 35 KT OUT OF THE DELTA TONIGHT AND
EARLY SATURDAY MORNING. IFR STRATUS MAY BE POSSIBLE NEAR THE DELTA
EARLY SATURDAY MORNING.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KMTR 032136
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
236 PM PDT FRI JUL 3 2009
.DISCUSSION...AS OF 2:35 PM PDT FRIDAY...SO FAR A VERY PLEASANT DAY
AROUND THE SAN FRANCISCO AND MONTEREY BAY AREA. SIMILAR TO YESTERDAY
THE STRATUS CLEARED OUT AND AFTERNOON TEMPERATURES HAVE MADE IT INTO
THE MID 60S TO LOWER 70S ALONG THE COAST AND MID 70S TO LOWER 90S
INLAND. A QUICK GLIMPSE AT THE VISIBLE SATELLITE IMAGE DOES SHOW
STRATUS JUST OFF OF THE COAST AND THE FORT ORD PROFILER IS
INDICATING THAT THE MARINE LAYER IS ABOUT 1600 FEET DEEP.
THEREFORE...EXPECT STRATUS TO RETURN TO THE AREA ONCE AGAIN TONIGHT.
TOMORROW...INDEPENDENCE DAY...WILL AGAIN BE PLEASANT WITH SIMILAR
CONDITIONS EXPECTED.
A COOL DOWN IS STILL EXPECTED BEGINNING EARLY NEXT WEEK. THIS IS
DUE TO A TROUGH OF LOW PRESSURE WHICH IS BEING WELL ADVERTISED BY
BOTH THE 1200 UTC ECMWF AND OPERATIONAL GFS. THE TROUGH IS EXPECTED
TO REACH THE PACIFIC NORTHWEST BY MONDAY MORNING AND 500MB HEIGHTS
WILL BEGIN TO FALL ACROSS THE CWA. THE ECMWF SEEMS TO BE COMING
INTO BETTER AGREEMENT WITH THE GFS ON THE MAGNITUDE OF THE LOW
HOWEVER THE GFS IS STILL RUNNING ABOUT 3 TO 5 DM LOWER AT 500MB.
WITH THE GFS ADVERTISING 850 TEMPERATURES TO DROP TO 10 DEGREES
CELSIUS TUESDAY MORNING OVER THE SAN FRANCISCO BAY AREA EXPECT
SURFACE TEMPERATURES OF ABOUT 68 IN SAN FRANCISCO AND 74 IN SAN JOSE.
ALTHOUGH...THE TWO MODELS ARE DIFFERING ON THE OF MAGNITUDE OF THIS
TROUGH BOTH SOLUTIONS ARE RATHER STRONG FOR THIS TIME OF YEAR.
&&
.AVIATION...AS OF 10:37 AM PDT FRIDAY...WIDESPREAD STRATUS ALONG THE
COAST WITH AN ONSHORE GRADIENT OF 1.7 MB. DEPTH IS ABOUT 1500 FEET
FEET PER FT ORD AND SODARS. WILL USE PERSISTENCE FORECAST BRINGING
STRATUS BACK IN OVERNIGHT...LATE IN THE BAY AREA...AFTER 08Z...AND
EARLIER AROUND MONTEREY BAY.
VICINITY OF KSFO...VFR CONDITIONS THIS AFTERNOON WITH OCCASIONAL
GUSTS AT KSFO. WILL ALLOW FOR SOME PATCHY STRATUS TONIGHT BUT MAYBE
A LITTLE LESS COMPARED TO THIS MORNING. CEILINGS AFTER 08Z.
KSFO BRIDGE APPROACH...SIMILAR CONDITIONS TO KSFO. APPROACH IS VFR.
MONTEREY BAY TERMINALS...VFR TODAY. STRATUS WILL MOVE IN EARLY
TONIGHT ONCE AGAIN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: SSA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 032055
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
155 PM PDT FRI JUL 3 2009
.SYNOPSIS...
SEASONAL STRONG HIGH PRESSURE CONTINUES FOR SOUTHWEST UNITED STATES
AND CALIFORNIA THROUGH MONDAY...ALONG WITH WARM TEMPERATURES AND LOW
HUMIDITIES INLAND. LOOK FOR SLIGHTLY COOLER BEGINNING TUESDAY AS THE
RIDGE OF HIGH PRESSURE MOVES EAST. COAST WILL CONTINUE COOLER WITH
AN ONGOING MARINE LAYER.
&&
.SHORT TERM (TODAY-MON)...TODAY VERY SIMILAR TO THE LAST SEVERAL
DAYS. MARINE LYR STICKING CLOSE TO THE BEACHES IN MANY AREAS,
DAYTIME TEMPS WITHIN 2 OR 3 DEGREES IN MOST LOCATIONS, AND NO
AFTERNOON CONVECTION IN THE MTNS AND DESERTS. REALLY DON`T SEE MUCH
CHANGE IN THIS PATTERN THROUGH THE HOLIDAY WEEKEND. PERHAPS AN EVER
SO SLIGHT DECREASE IN MARINE LYR DEPTH TONIGHT AND A DEGREE OR TWO
WARMER. OTHERWISE, WHAT YOU`VE SEEN IS WHAT YOU WILL GET.
.LONG TERM (TUE-FRI)...MODELS HAVE BEEN ADVERTISING A TROF ALONG THE
COAST FOR NEXT WEEK, AND WHILE THIS IS STILL THE CASE, 12Z GFS AND
ECMWF WERE BOTH WEAKER WITH IT, ESPECIALLY THE ECMWF, WITH MORE
EMPHASIS PLACED ON THE UPPER HIGH OVER SRN AZ/NRN MX. AS A RESULT,
MOS GUIDANCE HIGHS FOR NEXT WEEK WERE 3-5 DEGREES WARMER THAN
EARLIER RUNS. NUDGED UP HIGHS SLIGHTLY FOR NEXT WEEK, BUT OTHERWISE
LEFT THE FORECAST LARGELY UNCHANGED. THE TROF WILL CERTAINLY
MAINTAIN A DECENT MARINE LYR PRESENCE AT THE COAST WITH SOME INLAND
PUSH EACH NIGHT. DRY WEST/SOUTHWEST FLOW ALOFT WILL KEEP ALL
CONVECTION WELL TO THE EAST. OVERALL A VERY DULL FORECAST, BUT VERY
PLEASANT CONDITIONS ACROSS OUR AREA.
&&
.AVIATION...03/1915Z.
PORTIONS OF THE COAST WILL BE DEALING WITH THE MARINE LEECH (LOW
CLOUDS CLINGING TO THE COAST) THROUGH THE AFTERNOON...KLAX AND THE
CENTRAL COAST ESPECIALLY. KLAX MAY SEE AN OCCASIONAL BKN SKY
CONDITION THIS AFTERNOON AS COVERED IN THE TAF. THESE LOCATIONS WILL
ALSO BE SUSCEPTIBLE TO AN EARLY RETURN OF THE IFR CONDITIONS
ASSOCIATED WITH THE MARINE CLOUDS. PRETTY GOOD CONFIDENCE IN THE TAF
PACKAGE.
KLAX...GOOD CONFIDENCE IN SCT TO BKN CONDITIONS THIS AFTERNOON
FOLLOWED BY BKN TO OVC CONDITIONS WITH IFR CEILINGS EARLY THIS
EVENING THROUGH MUCH OF SATURDAY MORNING.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH SATURDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...WOFFORD
AVIATION...SWEET
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
[top]
000
FXUS66 KSGX 032028
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
130 PM PDT FRI JUL 3 2009
.SYNOPSIS...FAIR AND WARM WEATHER WILL CONTINUE THROUGH THE HOLIDAY
WEEKEND...EXCEPT ALONG THE COAST WHERE SEA BREEZES WILL KEEP THE
DAYS COOLER...AND PERIODS OF LOW CLOUDS AND FOG WILL CONTINUE. THERE
IS THE OUTSIDE CHANCE OF A SHOWER OR THUNDERSTORM OVER THE MOUNTAINS
AND DESERTS AS WELL. HIGH PRESSURE ALOFT WILL WEAKEN NEXT WEEK...
BRINGING STRONGER ONSHORE FLOW...COOLER WEATHER...AND MORE EXTENSIVE
LOW CLOUDS WEST OF THE MOUNTAINS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
VISIBLE SATELLITE IMAGERY AT 20Z SHOWED AREAS OF LOW CLOUDS/HAZE
ALONG THE IMMEDIATE COAST...AND CU OVER THE MOUNTAINS AND NORTHERN
DESERTS. OTHER PATCHY AREAS OF MID-LEVEL CLOUDS WERE DEVELOPING OVER
COASTAL AND VALLEY AREAS OF SAN DIEGO COUNTY. SURFACE PRESSURE
GRADIENTS WERE 5-7 MBS ONSHORE FROM THE COAST TO THE DESERTS. NO
SHOWERS WERE INDICATED BY RADAR THROUGH 20Z...BUT A SLIGHT CHANCE
FOR SHOWERS CONTINUES THROUGH THIS EVENING IN THE MOUNTAINS AND
DESERTS AS HEATING PROGRESSES.
HIGH PRESSURE CENTERED OVER TEXAS TODAY IS FORECAST TO EXPAND
WESTWARD ALONG 30N OVER THE WEEKEND. THIS WILL RESULT IN SLIGHT
HEIGHT/THICKNESS RISES OVER SOCAL THROUGH MON AND A STRENGTHENING
THERMAL LOW OVER THE LOWER COLORADO RIVER VALLEY. THE INCREASING
ONSHORE FLOW WILL COUNTER THE BUILDING HIGH ALOFT AND COME TO SOME
BALANCE WHICH WILL LIKELY BE SOME THINNING OF THE MARINE LAYER...
BUT A STRONGER INVERSION. EXPECT THIS WILL MAKE IT INCREASINGLY
DIFFICULT TO CLEAR THE BEACHES. JUST ENOUGH MOISTURE AND INSTABILITY
REMAIN IN THE MID-LEVELS TO KEEP A SLIGHT CHANCE OF THUNDER IN THE
FORECAST FOR THE MOUNTAINS AND DESERTS INTO SAT AFTERNOON/EVENING.
OTHERWISE...MOSTLY CLEAR INLAND FROM THE COAST.
THE FLOW OF MID-LEVEL MOISTURE GETS SHUT OFF AFTER SAT AS THE UPPER-
LEVEL HIGH PRESSURE RIDGE BUILDS DIRECTLY OVERHEAD...SO AFTER
THAT...ANY CHANCE OF A SHOWER OR THUNDERSTORM APPEARS TOO REMOTE TO
MENTION. BY SUN AND MON...UPPER LEVEL WESTERLY FLOW WILL BE
INCREASING AS LOW PRESSURE STRENGTHENS SOUTHWARD FROM THE PACNW AND
THE HIGH PRESSURE RIDGE SETTLES FARTHER SOUTH. THIS SHOULD SET US UP
FOR TYPICAL SOCAL EARLY SUMMER WEATHER WITH PERIODS OF NIGHT AND
MORNING LOW CLOUDS/FOG WEST OF THE MOUNTAINS AND MAX TEMPS RANGING
FROM THE 60S TO LOWER 70S AT THE BEACHES...TO THE 80S TO NEAR 90 IN
THE INLAND VALLEYS. FOR THE FOOTHILLS...MOUNTAINS AND DESERTS EXPECT
SLIGHT COOLING BUT CONTINUED QUITE WARM WITH MAX TEMPS IN THE 90S TO
NEAR 104 AT LOWER ELEVATIONS...AND LOCALLY GUSTY WINDS EACH
AFTERNOON AND EVENING MUCH OF THE WEEK.
AS NEXT WEEK PROGRESSES...THERE IS CONSIDERABLE DISAGREEMENT BETWEEN
THE 12Z ECMWF/GFS RUNS IN AMPLITUDE OF THE SUBTROPICAL HIGH OVER THE
LOWER 48. THE EC BUILDS A MASSIVE 599 MB CENTER NEAR THE FOUR
CORNERS AREA BY NEXT WEEKEND...WHILE THE GFS KEEPS A LOWER AMPLITUDE
RIDGE CENTERED FARTHER TO THE EAST. IT ALSO KEEPS A WEAK UPPER
TROUGH ALONG THE WEST COAST...WHICH WOULD KEEP OUR WEATHER MORE
SEASONAL. AT THIS TIME WOULD BE INCLINED TO FOLLOW SOMETHING CLOSER
TO THE GFS SOLUTION SINCE IT IS MORE CONSISTENT WITH PREVIOUS RUNS
AND THE EC IS NOT. THAT IMPLIES DRY AND SEASONAL CONDITIONS TO
PERSIST LATE IN THE WEEK.
&&
.AVIATION...
032015Z...MARINE LAYER DEPTH CURRENTLY NEAR FL018 AND FORECAST TO
LOWER TO FL012 DURING NEXT 12 HOURS DUE TO STRENGTHENING AND
LOWERING SUBSIDENCE INVERSION CAUSED BY BUILDING HIGH PRESSURE
ALOFT. CURRENTLY BROKEN-SCATTERED STRATUS LAYER OVER WATER AND
INLAND 5SM WITH BASES FL007-010 AND TOPS AROUND FL017. THIS LAYER
EXPECTED TO INCREASE TO OVERCAST AFTER 0300 UTC...THEN LAYER
LOWERING WITH BASES FL004 AND TOPS FL012...SPREADING SLOWLY INLAND
10-15SM AFTER 04/1000. STRATUS RETREATING BACK TO IMMEDIATE COAST
AFTER 04/1600 UTC BUT LIKELY REMAINING OVERCAST-BROKEN DUE TO
STRONGER INVERSION. OVER MOUNTAINS/DESERTS SCATTERED CLOUDS BETWEEN
FL100-FL200 THROUGH 0300 UTC AND AGAIN 04/1800-05/0300 UTC WITH
ISOLATED THUNDERSTORMS TO FL370.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...JAD
AVIATION...BALFOUR
000
FXUS66 KLOX 031915
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1215 PM PDT FRI JUL 3 2009
NEW AVIATION DISCUSSION
.SYNOPSIS...
SEASONAL STRONG HIGH PRESSURE CONTINUES FOR SOUTHWEST UNITED STATES
AND CALIFORNIA THROUGH MONDAY...ALONG WITH WARM TEMPERATURES AND LOW
HUMIDITIES INLAND. LOOK FOR SLIGHTLY COOLER BEGINNING TUESDAY AS THE
RIDGE OF HIGH PRESSURE MOVES EAST. COAST WILL CONTINUE COOLER WITH
AN ONGOING MARINE LAYER.
&&
.SHORT TERM (TODAY-SUN)...MARINE LYR JUST A TAD DEEPER THIS MORNING
AND LOCAL SOUNDINGS AND OBSERVATIONS CONFIRM 1-3 DEGREES COOLING AT
THE LOWER ELEVATIONS. SIMILAR IMPACT EXPECTED ON THE HIGHS FOR TODAY
AND THE LONG STRING OF BELOW NORMAL HIGHS AT DOWNTOWN LA WILL
CONTINUE FOR ANOTHER DAY AND QUITE LIKELY ANOTHER WEEK AT LEAST.
MODELS HAVE DONE A REALLY POOR JOB HANDLING THE MOISTURE AND
STABILITY PARAMETERS THIS WEEK AND WE`VE PULLED THE PLUG ON ANY
CONVECTIVE THREAT FOR THE MTNS AND DESERTS. NAM HAD SHOWN 850
DEWPOINTS IN EXCESS OF 10C FOR TODAY AND 12Z NKX SOUNDING INDICATED
A TD OF -7C SO NOT EVEN IN THE RIGHT ZIP CODE.
VERY LITTLE CHANGE EXPECTED FOR THE WEEKEND OVERALL. PROBABLY A
COUPLE DEGREES OF WARMING SOUTH OF PT CONCEPTION SAT/SUN AS HIGH
PRESSURE ALOFT STRENGTHENS SLIGHTLY. MARINE LYR WILL LIKELY REMAIN
AT OR AROUND 1200 FEET (+/- A FEW HUNDRED FEET), KEEPING CLOUDS
CONFINED TO THE COAST AND LOWER COASTAL VALLEYS OVERNIGHT. OVERALL
WEATHER EXCITEMENT METER IS EXTREMELY LOW.
*** LONG TERM FROM PREVIOUS DISCUSSION ***
.LONG TERM (MON-THU)...
EC AND GFS AGREE THAT PAC NW LOW WILL ROTATE THROUGH THE AREA MONDAY
THROUGH THU. NOT MUCH CHANGE MONDAY AS THE HGTS REMAIN NR 588.
ONSHORE FLOW MIGHT BE A LITTLE STRONGER WHICH WOULD HINDER BURN OFF
AT THE COAST. FROM TUESDAY ON THE TROF SETS UP OVER THE WEST COAST.
HGTS FALL TO NR 582DM AND ONSHORE FLOW INCREASES WHICH SHOULD BRING
THE MARINE LAYER INTO THE VLYS WHICH WILL LIKELY SEE 6 TO 10 DEGREES
OF COOLING AS A RESULT. COASTAL AREAS WILL NOT SEE MUCH CHANGE AND
THE INLAND AREAS WILL SEE SOME COOLING DUE TO THE LOWER HGTS.
&&
.AVIATION...03/1915Z.
PORTIONS OF THE COAST WILL BE DEALING WITH THE MARINE LEECH (LOW
CLOUDS CLINGING TO THE COAST) THROUGH THE AFTERNOON...KLAX AND THE
CENTRAL COAST ESPECIALLY. KLAX MAY SEE AN OCCASIONAL BKN SKY
CONDITION THIS AFTERNOON AS COVERED IN THE TAF. THESE LOCATIONS WILL
ALSO BE SUSCEPTIBLE TO AN EARLY RETURN OF THE IFR CONDITIONS
ASSOCIATED WITH THE MARINE CLOUDS. PRETTY GOOD CONFIDENCE IN THE TAF
PACKAGE.
KLAX...GOOD CONFIDENCE IN SCT TO BKN CONDITIONS THIS AFTERNOON
FOLLOWED BY BKN TO OVC CONDITIONS WITH IFR CEILINGS EARLY THIS
EVENING THROUGH MUCH OF SATURDAY MORNING.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH SATURDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...WOFFORD/RORKE
AVIATION...SWEET
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 031747 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1045 AM MST FRI JUL 3 2009
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
STRONG VORT MAX DID IN FACT DEVELOP OVERNIGHT ACROSS NORTHERN
SONORA/SE AZ...BUT FAILED TO PRODUCE PRECIPITATION ACROSS THE
FORECAST AREA. DEBRIS CLOUDINESS WITH THIS CIRCULATION HAS BEEN
CONFINED TO EASTERN AZ THIS MORNING. FULL SUNSHINE ACROSS MUCH OF
THE CWA MAKES TODAYS FORECAST MORE OF TEXTBOOK CASE. CLOUDS ARE
ALREADY FORMING ALONG THE MOGOLLON RIM AND ACROSS THE PEAKS OF NW
AZ. STEERING FLOW WILL CONTINUE TO VEER...SUGGESTING THAT ISOLATED
ACTIVITY ALONG THE RIM WILL SLOWLY WORK ITS WAY INTO THE LOWER
ELEVATIONS LATE THIS AFTERNOON AND THIS EVENING.
MODELS HAVE INITIALIZED WELL THIS MORNING AND INDICATE SUFFICIENT
CAPE FOR ISOLATED THUNDERSTORMS IN THE PHOENIX METRO AREA LATER
TODAY. EARLY 12Z ACARS SOUNDING SHOWED A LITTLE BIT OF A CAP AROUND
500 MB...THOUGH THAT HAS DIMINISHED AS OF 15Z. FLOW GENERALLY
REMAINS DIVERGENT ALOFT...THOUGH WITHOUT MUCH OF A DYNAMIC
TRIGGER...IT WILL TAKE INTENSE HEATING OR AN OUTFLOW BOUNDARY TO
REALIZE THE INSTABILITY.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
PREVIOUS DISCUSSION...
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
CU AND TCU BUILDING OVER MOUNTAINS AT 17Z PER 88D AND PIREPS...IN
RATHER MOIST ENVIRONMENT. IN FACT...YOUR LATEST PHOENIX SOUNDING HAD
1.69 INCHES OF P/WATER WITH A WEAK STABLE LAYER AT 20 THSD FEET.
CONVECTION IS UNDERWAY...AND STEERING FLOW REMAINS IDEAL FOR ISOLD
ACTIVITY TO DRIFT INTO THE AREA AFTER 00Z. OUTFLOW WINDS COULD
BE STRONG ENUF TO KICK UP DUST BUT STILL NOT CONFIDENT TOO SHOW THAT
HAZARD IN 18Z TAFS. FOR THE 4TH...WITH A POSSIBLE INCREASE IN
MOISTURE WE COULD SEE MORE CLOUDS BTWN 9 AND 12 THD FT.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS UNTIL LATE TOIGHT WHEN
SOUTHERLY WINDS KICK UP AND A GULF SURGE ARRIVES FOR YOUR 4TH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/ESTLE
AVIATION...SIPPLE
FIRE WEATHER...INIGUEZ
000
FXUS66 KMTR 031737
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1037 AM PDT FRI JUL 3 2009
...ANOTHER PLEASANT DAY IN-STORE FOR THE CENTRAL COAST...
.DISCUSSION...AS OF 9:03 AM PDT FRIDAY...TODAY WILL BE MUCH LIKE
YESTERDAY ACROSS THE DISTRICT WITH THE LATEST VISIBLE SATELLITE
IMAGE SHOWING STRATUS ALONG THE COAST AND INLAND VALLEYS. THE FORT
ORD PROFILER IS INDICATING THAT THE MARINE LAYER IS AROUND 1400 FEET
DEEP THIS MORNING WHICH IS SHALLOWER THAN AT THIS TIME YESTERDAY SO
EXPECT THE STRATUS TO BURN OFF SLIGHTLY EARLIER THIS MORNING. SKIES
WILL BECOME MOSTLY CLEAR WITH AFTERNOON TEMPERATURES EXPECTED TO
REACH THE MID 60S TO MID 70S ALONG THE COAST AND UPPER 70S TO LOW 90S
INLAND. TOMORROW...INDEPENDENCE DAY...WILL AGAIN BE PLEASANT WITH
SIMILAR CONDITIONS TO TODAY EXPECTED.
A COOL DOWN IS STILL EXPECTED BEGINNING EARLY NEXT WEEK. THIS IS
DUE TO A TROUGH OF LOW PRESSURE WHICH IS BEING WELL ADVERTISED BY
BOTH THE 0000 UTC ECMWF AND 0600 UTC GFS. THE TROUGH IS EXPECTED TO
REACH THE PACIFIC NORTHWEST BY MONDAY AND 500MB HEIGHTS WILL BEGIN TO
FALL ACROSS THE CWA. THE MODELS ARE HOWEVER DIFFERING ON THE
MAGNITUDE OF THE TROUGH BY 5 TO 10 DM OVER THE SAN FRANCISCO BAY AREA
SO JUST HOW MUCH SURFACE TEMPERATURE WILL FALL IS QUESTIONABLE.
ANOTHER INDICATOR OF COOLING IS THE 850 TEMPERATURE WHICH IS EXPECTED
TO DROP TO 10 DEGREES CELSIUS TUESDAY MORNING OVER THE BAY AREA
TRANSLATING TO A SURFACE TEMPERATURE OF ABOUT 68 IN SAN FRANCISCO
AND 74 IN SAN JOSE. ALTHOUGH...THE TWO MODELS ARE DIFFERING ON THE OF
MAGNITUDE OF THIS TROUGH BOTH SOLUTIONS ARE RATHER STRONG FOR
THIS TIME OF YEAR.
&&
.AVIATION...AS OF 10:37 AM PDT FRIDAY...WIDESPREAD STRATUS ALONG THE
COAST WITH AN ONSHORE GRADIENT OF 1.7 MB. DEPTH IS ABOUT 1500 FEET
FEET PER FT ORD AND SODARS. WILL USE PERSISTENCE FORECAST BRINGING
STRATUS BACK IN OVERNIGHT...LATE IN THE BAY AREA...AFTER 08Z...AND
EARLIER AROUND MONTEREY BAY.
VICINITY OF KSFO...VFR CONDITIONS THIS AFTERNOON WITH OCCASIONAL
GUSTS AT KSFO. WILL ALLOW FOR SOME PATCHY STRATUS TONIGHT BUT MAYBE
A LITTLE LESS COMPARED TO THIS MORNING. CEILINGS AFTER 08Z.
KSFO BRIDGE APPROACH...SIMILAR CONDITIONS TO KSFO. APPROACH IS VFR.
MONTEREY BAY TERMINALS...VFR TODAY. STRATUS WILL MOVE IN EARLY
TONIGHT ONCE AGAIN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDA...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: SSA
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KHNX 031722
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
1022 AM PDT FRI JUL 3 2009
.DISCUSSION...DRY SOUTHWEST FLOW ALOFT CONTINUES OVER THE REGION
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL SYNOPTIC PATTERN.
LOOK FOR GENERALLY SUNNY AND VERY WARM CONDITIONS TODAY...SIMILAR
TO YESTERDAY. HIGHS WILL AGAIN RUN SEVERAL DEGREES ABOVE
CLIMO...AROUND THE 100 DEGREE NEIGHBORHOOD IN THE VALLEY...LOWER
FOOTHILL AND DESERT ZONES. DO NOT EXPECT TO SEE ANY CONVECTION
DEVELOPING OVER OUR MOUNTAIN OR DESERT ZONES IN THE DRY FLOW
REGIME. NO UPDATE IS REQUIRED FOR THE FORECAST TODAY. A DEVELOPING
TROUGH IN THE NORTHEAST PACIFIC IS STILL EXPECTED TO BRING SOME
COOLING TO INTERIOR CENTRAL CALIFORNIA BY EARLY NEXT WEEK.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA
INTERIOR THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 3 2009... UNHEALTHY IN KERN COUNTY. UNHEALTHY FOR
SENSITIVE GROUPS IN FRESNO... KINGS... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JEB
AVN/FW...DCH
WEATHER.GOV/HANFORD
000
FXUS65 KPSR 031627
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
930 AM MST FRI JUL 3 2009
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
STRONG VORT MAX DID IN FACT DEVELOP OVERNIGHT ACROSS NORTHERN
SONORA/SE AZ...BUT FAILED TO PRODUCE PRECIPITATION ACROSS THE FORECAST
AREA. DEBRIS CLOUDINESS WITH THIS CIRCULATION HAS BEEN CONFINED TO
EASTERN AZ THIS MORNING. FULL SUNSHINE ACROSS MUCH OF THE CWA MAKES
TODAYS FORECAST MORE OF TEXTBOOK CASE. CLOUDS ARE ALREADY FORMING
ALONG THE MOGOLLON RIM AND ACROSS THE PEAKS OF NW AZ. STEERING FLOW
WILL CONTINUE TO VEER...SUGGESTING THAT ISOLATED ACTIVITY ALONG THE
RIM WILL SLOWLY WORK ITS WAY INTO THE LOWER ELEVATIONS LATE THIS
AFTERNOON AND THIS EVENING.
MODELS HAVE INITIALIZED WELL THIS MORNING AND INDICATE SUFFICIENT
CAPE FOR ISOLATED THUNDERSTORMS IN THE PHOENIX METRO AREA LATER
TODAY. EARLY 12Z ACARS SOUNDING SHOWED A LITTLE BIT OF A CAP AROUND
500 MB...THOUGH THAT HAS DIMINISHED AS OF 15Z. FLOW GENERALLY REMAINS
DIVERGENT ALOFT...THOUGH WITHOUT MUCH OF A DYNAMIC TRIGGER...IT WILL
TAKE INTENSE HEATING OR AN OUTFLOW BOUNDARY TO REALIZE THE
INSTABILITY.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
PREVIOUS DISCUSSION...
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EASTERLY FLOW TO CONTINUE INTO THIS EARLY AFTERNOON BEFORE SLOWLY
TURNING TO THE SW...ALBEIT WEAKLY. DATA FROM THIS MORNING/S BALLOON
LAUNCH SHOWS INSTABILITY HAS INCREASED FROM YESTERDAY YET A
WEAKENING CAP REMAINS. NO CLEAR TRIGGERING MECHANISMS EXPECTED FOR
THIS AFTERNOON SO CONVECTION MAY END UP BEING SPOTTY AND MORE AROUND
PHX THAN OVER IT. HAVE INCLUDED CBS AS WE/LL LIKELY SEE STORMS
WITHIN 50 NM OF THE AIRPORTS. LESS CLOUDS THIS MORNING THOUGH COULD
MEAN AN EARLIER START TO STORMS IN THE AREA...WE/LL WATCH HOW THINGS
DEVELOP THROUGH THE MORNING.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/ESTLE
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
000
FXUS66 KLOX 031614
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
915 AM PDT FRI JUL 3 2009
.SYNOPSIS...
SEASONAL STRONG HIGH PRESSURE CONTINUES FOR SOUTHWEST UNITED STATES
AND CALIFORNIA THROUGH MONDAY...ALONG WITH WARM TEMPERATURES AND LOW
HUMIDITIES INLAND. LOOK FOR SLIGHTLY COOLER BEGINNING TUESDAY AS THE
RIDGE OF HIGH PRESSURE MOVES EAST. COAST WILL CONTINUE COOLER WITH
AN ONGOING MARINE LAYER.
&&
.SHORT TERM (TODAY-SUN)...MARINE LYR JUST A TAD DEEPER THIS MORNING
AND LOCAL SOUNDINGS AND OBSERVATIONS CONFIRM 1-3 DEGREES COOLING AT
THE LOWER ELEVATIONS. SIMILAR IMPACT EXPECTED ON THE HIGHS FOR TODAY
AND THE LONG STRING OF BELOW NORMAL HIGHS AT DOWNTOWN LA WILL
CONTINUE FOR ANOTHER DAY AND QUITE LIKELY ANOTHER WEEK AT LEAST.
MODELS HAVE DONE A REALLY POOR JOB HANDLING THE MOISTURE AND
STABILITY PARAMETERS THIS WEEK AND WE`VE PULLED THE PLUG ON ANY
CONVECTIVE THREAT FOR THE MTNS AND DESERTS. NAM HAD SHOWN 850
DEWPOINTS IN EXCESS OF 10C FOR TODAY AND 12Z NKX SOUNDING INDICATED
A TD OF -7C SO NOT EVEN IN THE RIGHT ZIP CODE.
VERY LITTLE CHANGE EXPECTED FOR THE WEEKEND OVERALL. PROBABLY A
COUPLE DEGREES OF WARMING SOUTH OF PT CONCEPTION SAT/SUN AS HIGH
PRESSURE ALOFT STRENGTHENS SLIGHTLY. MARINE LYR WILL LIKELY REMAIN
AT OR AROUND 1200 FEET (+/- A FEW HUNDRED FEET), KEEPING CLOUDS
CONFINED TO THE COAST AND LOWER COASTAL VALLEYS OVERNIGHT. OVERALL
WEATHER EXCITEMENT METER IS EXTREMELY LOW.
*** LONG TERM FROM PREVIOUS DISCUSSION ***
.LONG TERM (MON-THU)...
EC AND GFS AGREE THAT PAC NW LOW WILL ROTATE THROUGH THE AREA MONDAY
THROUGH THU. NOT MUCH CHANGE MONDAY AS THE HGTS REMAIN NR 588.
ONSHORE FLOW MIGHT BE A LITTLE STRONGER WHICH WOULD HINDER BURN OFF
AT THE COAST. FROM TUESDAY ON THE TROF SETS UP OVER THE WEST COAST.
HGTS FALL TO NR 582DM AND ONSHORE FLOW INCREASES WHICH SHOULD BRING
THE MARINE LAYER INTO THE VLYS WHICH WILL LIKELY SEE 6 TO 10 DEGREES
OF COOLING AS A RESULT. COASTAL AREAS WILL NOT SEE MUCH CHANGE AND
THE INLAND AREAS WILL SEE SOME COOLING DUE TO THE LOWER HGTS.
&&
.AVIATION...03/1200Z.
A 1200 FOOT MARINE LAYER WILL BRING LOW CLOUDS INTO ALL THE COASTAL
AIR FIELDS. BURN OFF WILL LIKELY OCCUR DURING THE LATE MORNING.
SITES VERY CLOSE TO THE BEACHES COULD SEE SOME CIGS DURING THE
AFTERNOON. LOW CLOUDS WILL LIKELY RETURN EARLY THIS EVENING TO THE
COASTAL SITES. NO WIND ISSUES TODAY.
KLAX...GOOD CONFIDENCE IN TAF. MVFR CIGS WILL LIKELY PULSE IN AND
OUT THIS AFTERNOON.
KBUR...VERY GOOD CONFIDENCE IN VFR TAF.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...WOFFORD/RORKE
AVIATION...BRUNO
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 031603
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
903 AM PDT FRI JUL 3 2009
...ANOTHER PLEASANT DAY IN-STORE FOR THE CENTRAL COAST...
.DISCUSSION...AS OF 9:03 AM PDT FRIDAY...TODAY WILL BE MUCH LIKE
YESTERDAY ACROSS THE DISTRICT WITH THE LATEST VISIBLE SATELLITE
IMAGE SHOWING STRATUS ALONG THE COAST AND INLAND VALLEYS. THE FORT
ORD PROFILER IS INDICATING THAT THE MARINE LAYER IS AROUND 1400 FEET
DEEP THIS MORNING WHICH IS SHALLOWER THAN AT THIS TIME YESTERDAY SO
EXPECT THE STRATUS TO BURN OFF SLIGHTLY EARLIER THIS MORNING. SKIES
WILL BECOME MOSTLY CLEAR WITH AFTERNOON TEMPERATURES EXPECTED TO
REACH THE MID 60S TO MID 70S ALONG THE COAST AND UPPER 70S TO LOW 90S
INLAND. TOMORROW...INDEPENDENCE DAY...WILL AGAIN BE PLEASANT WITH
SIMILAR CONDITIONS TO TODAY EXPECTED.
A COOL DOWN IS STILL EXPECTED BEGINNING EARLY NEXT WEEK. THIS IS
DUE TO A TROUGH OF LOW PRESSURE WHICH IS BEING WELL ADVERTISED BY
BOTH THE 0000 UTC ECMWF AND 0600 UTC GFS. THE TROUGH IS EXPECTED TO
REACH THE PACIFIC NORTHWEST BY MONDAY AND 500MB HEIGHTS WILL BEGIN TO
FALL ACROSS THE CWA. THE MODELS ARE HOWEVER DIFFERING ON THE
MAGNITUDE OF THE TROUGH BY 5 TO 10 DM OVER THE SAN FRANCISCO BAY AREA
SO JUST HOW MUCH SURFACE TEMPERATURE WILL FALL IS QUESTIONABLE.
ANOTHER INDICATOR OF COOLING IS THE 850 TEMPERATURE WHICH IS EXPECTED
TO DROP TO 10 DEGREES CELSIUS TUESDAY MORNING OVER THE BAY AREA
TRANSLATING TO A SURFACE TEMPERATURE OF ABOUT 68 IN SAN FRANCISCO
AND 74 IN SAN JOSE. ALTHOUGH...THE TWO MODELS ARE DIFFERING ON THE OF
MAGNITUDE OF THIS TROUGH BOTH SOLUTIONS ARE RATHER STRONG FOR
THIS TIME OF YEAR.
&&
.AVIATION...AS OF 4:23 AM PDT FRIDAY...WIDESPREAD STRATUS ALONG THE
COAST IS NOW INLAND WITH AN ONSHORE GRADIENT OF 2.5-3MB. DEPTH IS
ROUGHLY 1300-1600 FEET PER FT ORD AND SODARS. WILL USE PERSISTENCE
TODAY WHICH MEANS 16-18Z FOR CLEARING. STRATUS TONIGHT WILL BE
DIFFICULT AS MODEL GUIDANCE SUGGEST LESS BL MOISTURE AND A SLIGHT N
TO NE FLOW OVER THE N BAY.
VICINITY OF KSFO...STRATUS COVERS THE ENTIRE BAY WITH CIGS 1200-1400
FEET. CLEARING TIME WILL BE CLOSE TO YESTERDAY AROUND 17-1730Z. VFR
CONDITIONS THIS AFTERNOON WITH AN OCCASIONAL GUST AT KSFO. WILL
ALLOW FOR SOME PATCHY STRATUS TONIGHT BUT MAYBE A LITTLE LESS
COMPARED TO THIS MORNING.
KSFO BRIDGE APPROACH...SIMILAR CONDITIONS TO KSFO. APPROACH MAY
CLEAR A LITTLE LATER THAN KSFO.
MONTEREY BAY TERMINALS...STRATUS OVER MRY BAY THROUGH AT
LEAST 18Z. CIGS CLOSE TO 800-1200 FEET. STRATUS WILL MOVE IN EARLY
TONIGHT ONCE AGAIN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: MM
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KSGX 031541
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
840 AM PDT FRI JUL 3 2009
.SYNOPSIS...FAIR AND WARM WEATHER WILL CONTINUE THROUGH THE HOLIDAY
WEEKEND...EXCEPT ALONG THE COAST WHERE SEA BREEZES WILL KEEP THE
DAYS COOLER...AND PERIODS OF LOW CLOUDS AND FOG WILL CONTINUE. THERE
IS THE OUTSIDE CHANCE OF A SHOWER OR THUNDERSTORM OVER THE MOUNTAINS
AND DESERTS AS WELL. HIGH PRESSURE ALOFT WILL WEAKEN NEXT WEEK...
BRINGING STRONGER ONSHORE FLOW...COOLER WEATHER...AND MORE EXTENSIVE
LOW CLOUDS WEST OF THE MOUNTAINS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
BASED ON PIREPS AND OBSERVATIONS...MARINE STRATUS LAYER ALONG THE
COAST AT 15Z THIS MORNING IS ABOUT 800 FT THICK. THE 12Z MIRAMAR
SOUNDING HAD THE BASE OF THE 10 DEGREE C INVERSION NEAR 1500 FT.
SURFACE PRESSURE GRADIENTS WERE RUNNING ABOUT 5 MBS ONSHORE TO THE
LOWER DESERTS. FARTHER INLAND...A FEW CLOUDS WERE ALREADY EVIDENT
OVER THE MOUNTAINS OF SAN BERNARDINO AND RIVERSIDE COUNTIES.
NOT MUCH CHANGE AGAIN TODAY AS WE REMAIN IN A PERSISTENT ONSHORE
FLOW PATTERN WITH THE THERMAL LOW WELL DEVELOPED OVER THE LOWER
DESERTS AND HIGH PRESSURE ALOFT. THE HIGH IS FORECAST TO STRENGTHEN
SLIGHTLY AND HOLD INTO MON. SEA SURFACE TEMPS IN THE 50S AND 60S...
COMBINED WITH MODERATE ONSHORE FLOW WILL ENSURE TEMPS REMAIN IN
CHECK ALONG THE COAST...AND PERIODS OF LOW CLOUDS AND FOG CONTINUE.
DUE TO THE STRONG INVERSION...WHICH MAY LOWER FURTHER INTO SUN...LOW
CLOUDS/FOG/HAZE MAY LINGER AT SOME BEACHES INTO THE AFTERNOONS FOR
THE BALANCE OF THE HOLIDAY WEEKEND. JUST ENOUGH MOISTURE AND
INSTABILITY REMAIN IN THE MID-LEVELS TO KEEP A SLIGHT CHANCE OF
THUNDER IN THE FORECAST FOR THE MOUNTAINS AND DESERTS.
THE FLOW OF MID-LEVEL MOISTURE GETS SHUT OFF AFTER SAT AS THE UPPER-
LEVEL HIGH PRESSURE RIDGE BUILDS DIRECTLY OVERHEAD...SO AFTER THAT
ANY CHANCE OF A SHOWER OR THUNDERSTORM APPEARS TOO REMOTE TO
MENTION. BY SUN AND MON...UPPER LEVEL WESTERLY FLOW WILL BE
INCREASING AS LOW PRESSURE STRENGTHENS SOUTHWARD FROM THE PACNW AND
THE HIGH PRESSURE RIDGE SETTLES FARTHER SOUTH. THIS SHOULD SET US UP
FOR TYPICAL SOCAL EARLY SUMMER WEATHER WITH PERIODS OF NIGHT AND
MORNING LOW CLOUDS/ FOG WEST OF THE MOUNTAINS AND MAX TEMPS RANGING
FROM THE 60S TO LOWER 70S AT THE BEACHES...TO THE 80S TO NEAR 90 IN
THE INLAND VALLEYS. FOR THE FOOTHILLS...MOUNTAINS AND DESERTS EXPECT
WARM TO HOT AND SUNNY DAYS WITH MAX TEMPS IN THE 90S TO NEAR 104 AT
LOWER ELEVATIONS...AND LOCALLY GUSTY WINDS EACH AFTERNOON AND
EVENING MUCH OF THE WEEK.
LOOKING AHEAD TO NEXT WEEKEND...THERE IS SOME DISAGREEMENT BETWEEN
THE LATEST AVAILABLE ECMWF AND THE GFS SOLUTIONS. BOTH MODELS KEEP
THE MASSIVE SUBTROPICAL...SUMMER HIGH CENTERED OVER THE GREAT
PLAINS...BUT THE EC BUILDS HEIGHTS FARTHER TO THE WEST...WHICH
THROWS US INTO A WEAK SE FLOW ALOFT AND COULD REOPEN THE DOOR TO
ISOLATED CONVECTION. THE GFS HOLDS ONTO LOWER 500 MB HEIGHTS ALONG
THE W COAST AND LOOKS MUCH DRIER. TEMPS SHOULD BE CLOSE TO SEASONAL
AVERAGES WITH EITHER PATTERN...BUT THE GFS WOULD BE A BIT COOLER...
AND THE ECMWF A BIT WARMER.
&&
.AVIATION...
031445Z...MARINE LAYER DEPTH BELOW FL020. OVERCAST STRATUS LAYER
WITH BASES FL007-010 AND TOPS AROUND FL017 EXTENDING INLAND 15-20SM
AND BEGINNING TO RETREAT. BELOW STRATUS LAYER VISIBILITY 2-5SM IN
HAZE. SUBSIDENCE INVERSION STILL VERY STRONG...ABOUT 11C/17F BETWEEN
FL018-FL030 SO EXPECT BROKEN-SCATTERED STRATUS WILL PERSIST OVER
WATER AND INLAND 3-5SM AFTER 1700 UTC THEN INCREASE BACK TO OVERCAST
AFTER 0300 UTC. INVERSION WILL BECOME EVEN STRONGER AND LOWER
TONIGHT/SATURDAY DUE TO BUILDING HIGH PRESSURE ALOFT AND STRATUS
LAYER BASES SHOULD LOWER TO AROUND FL004 WHICH WOULD IMPACT KCRQ
WITH VERY LOW VISIBILITY/CEILINGS AND OTHER COASTAL
AIRPORTS...KSNA/KSAN WITH LOW CEILINGS DURING EARLY/MID MORNING
HOURS SATURDAY...04/1000-1600 UTC. OVER MOUNTAINS/DESERTS STILL
ENOUGH RESIDUAL MOISTURE FOR CUMULUS CLOUDS BETWEEN FL100-FL200 BUT
WITH AIRMASS BECOMING MORE STABLE ONLY ISOLATED THUNDERSTORMS
EXPECTED WITH TOPS TO FL370...AND THESE MORE LIKELY WILL FORM WELL
SOUTH...OVER BAJA CALIFORNIA MOUNTAINS...OR WELL TO THE NORTH...WITH
LITTLE TO NO IMPACT ON SOUTHERN APPROACH ROUTES.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...JAD
AVIATION...BALFOUR
000
FXUS66 KSTO 031530
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
830 AM PDT FRI JUL 03 2009
.DISCUSSION...
UPPER LOW IS APPROACHING THE NORTHWEST CAL COAST THIS MORNING AND IS
FORECAST TO GRADUALLY FILL AS IT SLOWLY LIFTS ACROSS THE FAR
NORTHERN INTERIOR LATE TODAY THROUGH TONIGHT. SOME INSTABILITY
DEPICTED OVER THE NORTHERN AND NORTHEAST MOUNTAINS THIS AFTERNOON
WITH GREATEST AMOUNT OVER THE COASTAL MOUNTAINS IN CLOSER PROXIMITY
TO LOW CENTER. THIS AREA ALSO HAVING HIGHEST PWS THIS AFTERNOON AND
WILL BE BEST CHANCES FOR AFTERNOON DEEP MOIST CONVECTION HOWEVER
PROBABILITY REMAINS IN THE SLIGHT CATEGORY. DRIER SOUTHWESTERLY
MID-LEVEL FLOW SOUTH OF A KCIC-KSVE LINE AND STRONGER MID-LEVEL CAP
PER KRNO SOUNDING EXPECTED TO KEEP REMAINDER OF WESTERN PORTIONS OF
SIERRA NEVADA STORM FREE TODAY.
850 MB TEMPS ONLY DROP ABOUT A DEGREE OR SO OVER THE INTERIOR THUS
AFTERNOON HIGHS TODAY EXPECTED TO BE NEAR TO SLIGHTLY COOLER.
EXCEPTION MAY BE NEAR THE DELTA AND NEARBY VALLEY LOCALES AS ONSHORE
GRADIENT IS WEAKER AND MARINE LAYER SHALLOWER THAN YESTERDAY.
DRIER SOUTHWESTERLY FLOW OVER ALL OF NORCAL SATURDAY WITH NEAR TO
SLIGHTLY WARMER TEMPS FOR THE INTERIOR. ANOTHER LOW PRESSURE SYSTEM
DEEPENS IN THE EASTERN PACIFIC AND FORECAST TO LIFT ACROSS THE PAC
NW SUN INTO MONDAY AS LONG WAVE TROUGH BECOMES ESTABLISHED NEAR
130W. THIS SETS UP COOLING TREND SUNDAY INTO WEDNESDAY WITH
INCREASED ONSHORE FLOW AND SYNOPTIC COOLING AS SERIES OF SHORT WAVES
MOVE INTO PAC NW. VALLEY TEMPS EXPECTED IN THE 80S MONDAY THROUGH
THURSDAY OF NEXT WEEK WITH 60S TO 70S IN THE HIGHER ELEVATIONS.
ECMWF/GFS KEEP ANY PRECIP WITH ASSOCIATED SHORT WAVES MAINLY ALONG
THE FAR NW CAL COAST AND NEAR THE ORCA BORDER NORTHWARD. PERIODS OF
GUSTY SOUTHWEST WIND THROUGH THE DELTA AND OVER HIGHER TERRAIN CAN
BE EXPECTED NEXT WEEK WITH PASSING SHORT WAVES.
PCH
&&
.AVIATION...
UPR LOW FCST TO GRDLY WKN AS IT SLOLY MOVS ACRS FAR NRN INTR TNGT.
VFR CONDS OVR INTR NORCAL EXC ISOLD MVFR/IFR POSS IN -TSRA N OF A
KUKI-KCIC-KSVE LN BTWN 22Z-04Z AND ISOLD IFR IN ST NEAR DELTA TIL
17Z. S-SWLY FLOW ALF BCMG WLY TNGT.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPSR 031256 AAA
AFDPSR
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PHOENIX AZ
555 AM MST FRI JUL 3 2009
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
EVENING CONVECTION LAST NIGHT WENT TO BED PRETTY QUICKLY...AND EARLY
MORNING SATELLITE PIX SHOW GENERALLY CLEAR SKIES ACROSS MOST OF THE
PHX CWA. ONLY EXCEPTION TO THIS WAS OVER THE FAR ERN CWA...WHERE A
LARGE SWWD PROPAGATING MCS DOWN OVER SONORA MEXICO WAS THROWING SOME
MID/HIGH LEVEL MOISTURE UP THAT WAY.
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EASTERLY FLOW TO CONTINUE INTO THIS EARLY AFTERNOON BEFORE SLOWLY
TURNING TO THE SW...ALBEIT WEAKLY. DATA FROM THIS MORNING/S BALLOON
LAUNCH SHOWS INSTABILITY HAS INCREASED FROM YESTERDAY YET A
WEAKENING CAP REMAINS. NO CLEAR TRIGGERING MECHANISMS EXPECTED FOR
THIS AFTERNOON SO CONVECTION MAY END UP BEING SPOTTY AND MORE AROUND
PHX THAN OVER IT. HAVE INCLUDED CBS AS WE/LL LIKELY SEE STORMS
WITHIN 50 NM OF THE AIRPORTS. LESS CLOUDS THIS MORNING THOUGH COULD
MEAN AN EARLIER START TO STORMS IN THE AREA...WE/LL WATCH HOW THINGS
DEVELOP THROUGH THE MORNING.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...ESTLE
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
000
FXUS66 KLOX 031155
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PDT FRI JUL 3 2009
.SYNOPSIS...
SOUTHWEST FLOW ALOFT AND ONSHORE FLOW AT THE SURFACE WILL KEEP A
COASTAL MARINE LAYER PATTERN AND A WARM CLEAR INLAND REGIME IN PLACE
THROUGH MONDAY. AFTER TUESDAY AN UPPER LOW WILL DEEPEN THE MARINE
LAYER AND LOWER TEMPERATURES.
&&
.SHORT TERM (TODAY-SUN)...
VERY DULL WEATHER PATTERN ON TAP FOR THE NEXT FEW DAYS OR MORE.
THROUGH SUNDAY SOCAL WILL BE IN BETWEEN A LARGE HIGH PRESSURE SYSTEM
OVER THE CENTER OF THE COUNTRY AND LOW PRESSURE OVER THE EAST PAC.
THE RESULTANT BENIGN SW FLOW PATTERN WILL KEEP A FAIR WEATHER
PATTERN OVER THE AREA. THE SW FLOW WILL BE DRY AND THERE WILL BE NO
CHC OF TSTMS. THE HGTS ARE QUITE HIGH BETWEEN 588 AND 590 DM SO THE
MARINE LAYER WILL BE SQUASHED OUT OF THE VLYS. THE HIGH HGTS WILL
ALSO ALLOW FOR ABOVE NORMAL TEMPS OVER THE VLYS MTNS AND DESERTS.
THE NIGHT THROUGH MORNING LOW CLOUD PATTERN WILL CONTINUE OVER THE
COASTAL SECTIONS WHERE MAX TEMPS WILL BE A FEW DEGREES BELOW NORMAL.
(DOWNTOWN HAS BEEN BELOW NORMAL EVERY DAY NOW SINCE MAY 21ST OR 43
DAYS NOW)
.LONG TERM (MON-THU)...
EC AND GFS AGREE THAT PAC NW LOW WILL ROTATE THROUGH THE AREA MONDAY
THROUGH THU. NOT MUCH CHANGE MONDAY AS THE HGTS REMAIN NR 588.
ONSHORE FLOW MIGHT BE A LITTLE STRONGER WHICH WOULD HINDER BURN OFF
AT THE COAST. FROM TUESDAY ON THE TROF SETS UP OVER THE WEST COAST.
HGTS FALL TO NR 582DM AND ONSHORE FLOW INCREASES WHICH SHOULD BRING
THE MARINE LAYER INTO THE VLYS WHICH WILL LIKELY SEE 6 TO 10 DEGREES
OF COOLING AS A RESULT. COASTAL AREAS WILL NOT SEE MUCH CHANGE AND
THE INLAND AREAS WILL SEE SOME COOLING DUE TO THE LOWER HGTS.
&&
.AVIATION...
03/1200Z.
A 1200 FOOT MARINE LAYER WILL BRING LOW CLOUDS INTO ALL THE COASTAL
AIR FIELDS. BURN OFF WILL LIKELY OCCUR DURING THE LATE MORNING.
SITES VERY CLOSE TO THE BEACHES COULD SEE SOME CIGS DURING THE
AFTERNOON. LOW CLOUDS WILL LIKELY RETURN EARLY THIS EVENING TO THE
COASTAL SITES. NO WIND ISSUES TODAY.
KLAX...GOOD CONFIDENCE IN TAF. MVFR CIGS WILL LIKELY PULSE IN AND
OUT THIS AFTERNOON.
KBUR...VERY GOOD CONFIDENCE IN VFR TAF.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...BRUNO
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 031127
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
427 AM PDT FRI JUL 3 2009
.DISCUSSION...AS OF 3:50 AM PDT FRIDAY...IF YOU LIKED THE WEATHER
YESTERDAY THEN YOU WILL LIKE TODAY AS WELL WITH LITTLE CHANGE IN THE
PATTERN. SATL IMAGERY INDC STRATUS ALONG THE COAST AND INTO THE BAYS
AND COASTAL VALLEYS. THE FORT ORD PROFILER IS INDC A MARINE INVERSION
AROUND 1600 FEET DEEP. TEMPS THIS MORNING ARE MAINLY IN THE 50S...
WITH 60S AND 70S IN THE HILLS ABOVE THE MARINE LAYER. TEMPS ARE
LITTLE CHANGED FROM YESTERDAY MORNING. THE GRADIENT PICTURE IS ALSO
LITTLE CHANGED...A RELATIVELY FLAT GRADIENT BETWEEN ARCATA-SFO AND A
2.7 MB ONSHORE GRADIENT BETWEEN SFO-SAC.
MODELS ARE IN AGREEMENT IN BUILDING A WEAK SHORTWAVE RIDGE...WHICH IS
IN RESPONSE TO A DEEPENING TROF ALONG 140W. THIS COULD BRING A FEW
DEGREES OF WARMING INLAND...OTHERWISE LITTLE CHANGE WITH STRATUS
ALONG THE COAST. THE TROF SLOWLY DEEPENS AND MOVES TO THE COAST OVER
THE WEEKEND...FLATTENING THE RIDGE. THE TROF WILL MOVE INTO THE COAST
AND CONTINUE TO DEEPEN. THIS TROF WILL BE UNUSUALLY STRONG FOR THIS
TIME OF YEAR. WHILE THERE WILL NOT BE ANY PRECIPITATION TEMPS WILL BE
QUITE COOL FOR THIS TIME OF YEAR...IN FACT TEMPS WILL BE ANYWHERE
FROM 5 TO AS MUCH AS 15 DEGREES BELOW NORMAL. THE BIGGEST QUESTION
WILL BE THE STRATUS. THE ECMWF HAS A MORE NORTHERLY FLOW...KEEPING
THE STRATUS OUT OF THE NORTH BAY WHILE THE GFS HAS MORE OF A NNW FLOW
WHICH COULD KEEP STRATUS IN THE NORTH BAY. THE GFS CONTINUES TO BE
SEVERAL DEGREES COOLER AT 850 MB...WHICH IF VERIFIES WOULD MIX OUT
THE MARINE LAYER. IF THAT HAPPENS...THE COAST COULD BE WARMER THAN
FORECAST. REGARDLESS...TEMPS INLAND WILL BE MORE LIKE LATE MAY THAN
EARLY JULY. HIGH PRESSURE BEGINS TO BUILD INTO THE STATE FROM THE
DESERT SW BY THE END OF NEXT WEEK FOR WARMER TEMPERATURES.
&&
.AVIATION...AS OF 4:23 AM PDT FRIDAY...WIDESPREAD STRATUS ALONG THE
COAST IS NOW INLAND WITH AN ONSHORE GRADIENT OF 2.5-3MB. DEPTH IS
ROUGHLY 1300-1600 FEET PER FT ORD AND SODARS. WILL USE PERSISTENCE
TODAY WHICH MEANS 16-18Z FOR CLEARING. STRATUS TONIGHT WILL BE
DIFFICULT AS MODEL GUIDANCE SUGGEST LESS BL MOISTURE AND A SLIGHT N
TO NE FLOW OVER THE N BAY.
VICINITY OF KSFO...STRATUS COVERS THE ENTIRE BAY WITH CIGS 1200-1400
FEET. CLEARING TIME WILL BE CLOSE TO YESTERDAY AROUND 17-1730Z. VFR
CONDITIONS THIS AFTERNOON WITH AN OCCASIONAL GUST AT KSFO. WILL
ALLOW FOR SOME PATCHY STRATUS TONIGHT BUT MAYBE A LITTLE LESS
COMPARED TO THIS MORNING.
KSFO BRIDGE APPROACH...SIMILAR CONDITIONS TO KSFO. APPROACH MAY
CLEAR A LITTLE LATER THAN KSFO.
MONTEREY BAY TERMINALS...STRATUS OVER MRY BAY THROUGH AT
LEAST 18Z. CIGS CLOSE TO 800-1200 FEET. STRATUS WILL MOVE IN EARLY
TONIGHT ONCE AGAIN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: MHS
AVIATION/MARINE: MM
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 031110
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
410 AM PDT FRI JUL 3 2009
.DISCUSSION...AS OF 3:50 AM PDT FRIDAY...IF YOU LIKED THE WEATHER
YESTERDAY THEN YOU WILL LIKE TODAY AS WELL WITH LITTLE CHANGE IN THE
PATTERN. SATL IMAGERY INDC STRATUS ALONG THE COAST AND INTO THE BAYS
AND COASTAL VALLEYS. THE FORT ORD PROFILER IS INDC A MARINE INVERSION
AROUND 1600 FEET DEEP. TEMPS THIS MORNING ARE MAINLY IN THE 50S...
WITH 60S AND 70S IN THE HILLS ABOVE THE MARINE LAYER. TEMPS ARE
LITTLE CHANGED FROM YESTERDAY MORNING. THE GRADIENT PICTURE IS ALSO
LITTLE CHANGED...A RELATIVELY FLAT GRADIENT BETWEEN ARCATA-SFO AND A
2.7 MB ONSHORE GRADIENT BETWEEN SFO-SAC.
MODELS ARE IN AGREEMENT IN BUILDING A WEAK SHORTWAVE RIDGE...WHICH IS
IN RESPONSE TO A DEEPENING TROF ALONG 140W. THIS COULD BRING A FEW
DEGREES OF WARMING INLAND...OTHERWISE LITTLE CHANGE WITH STRATUS
ALONG THE COAST. THE TROF SLOWLY DEEPENS AND MOVES TO THE COAST OVER
THE WEEKEND...FLATTENING THE RIDGE. THE TROF WILL MOVE INTO THE COAST
AND CONTINUE TO DEEPEN. THIS TROF WILL BE UNUSUALLY STRONG FOR THIS
TIME OF YEAR. WHILE THERE WILL NOT BE ANY PRECIPITATION TEMPS WILL BE
QUITE COOL FOR THIS TIME OF YEAR...IN FACT TEMPS WILL BE ANYWHERE
FROM 5 TO AS MUCH AS 15 DEGREES BELOW NORMAL. THE BIGGEST QUESTION
WILL BE THE STRATUS. THE ECMWF HAS A MORE NORTHERLY FLOW...KEEPING
THE STRATUS OUT OF THE NORTH BAY WHILE THE GFS HAS MORE OF A NNW FLOW
WHICH COULD KEEP STRATUS IN THE NORTH BAY. THE GFS CONTINUES TO BE
SEVERAL DEGREES COOLER AT 850 MB...WHICH IF VERIFIES WOULD MIX OUT
THE MARINE LAYER. IF THAT HAPPENS...THE COAST COULD BE WARMER THAN
FORECAST. REGARDLESS...TEMPS INLAND WILL BE MORE LIKE LATE MAY THAN
EARLY JULY. HIGH PRESSURE BEGINS TO BUILD INTO THE STATE FROM THE
DESERT SW BY THE END OF NEXT WEEK FOR WARMER TEMPERATURES.
&&
.AVIATION...AS OF 10:30 PM PDT THURSDAY...STRATUS IS STARTING TO
FILTR INTO SFO AND MRY BAY. BASES WILL BE BELOW 1000 FEET NEAR THE
COAST AND 1000-1200 FEET INLAND.
VICINITY OF KSFO...STRATUS SPREADING THROUGH THE GAPS WILL MOVE
OVER SFO BY 09Z AND STAY THROUGH 17-18Z WITH BASES AROUND
1000-1200 FEET.
KSFO BRIDGE APPROACH...STRATUS WILL AFFECT THE APPROACH AFTER 08Z.
BASES EXPECTED TO BE AROUND 1000-1200 FEET. CLEARING BY 18Z.
MONTEREY BAY TERMINALS...STRATUS GRADUALLY SPREADING OVER ALL OF
MRY BAY WITH CEILINGS STARTING OUT AT 1000-1500 FEET BEFORE LOWERING
TO 500-1000 FEET A COUPLE OF HOURS LATER. CLEARING BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: MHS
AVIATION/MARINE: W PI/MM
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 031055
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
355 AM MST FRI JUL 3 2009
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
EVENING CONVECTION LAST NIGHT WENT TO BED PRETTY QUICKLY...AND EARLY
MORNING SATELLITE PIX SHOW GENERALLY CLEAR SKIES ACROSS MOST OF THE
PHX CWA. ONLY EXCEPTION TO THIS WAS OVER THE FAR ERN CWA...WHERE A
LARGE SWWD PROPAGATING MCS DOWN OVER SONORA MEXICO WAS THROWING SOME
MID/HIGH LEVEL MOISTURE UP THAT WAY.
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...ESTLE
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS66 KLOX 031051
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PDT FRI JUL 3 2009
.SYNOPSIS...
SOUTHWEST FLOW ALOFT AND ONSHORE FLOW AT THE SURFACE WILL KEEP A
COASTAL MARINE LAYER PATTERN AND A WARM CLEAR INLAND REGIME IN PLACE
THROUGH MONDAY. AFTER TUESDAY AN UPPER LOW WILL DEEPEN THE MARINE
LAYER AND LOWER TEMPERATURES.
&&
.SHORT TERM (TODAY-SUN)...
VERY DULL WEATHER PATTERN ON TAP FOR THE NEXT FEW DAYS OR MORE.
THROUGH SUNDAY SOCAL WILL BE IN BETWEEN A LARGE HIGH PRESSURE SYSTEM
OVER THE CENTER OF THE COUNTRY AND LOW PRESSURE OVER THE EAST PAC.
THE RESULTANT BENIGN SW FLOW PATTERN WILL KEEP A FAIR WEATHER
PATTERN OVER THE AREA. THE SW FLOW WILL BE DRY AND THERE WILL BE NO
CHC OF TSTMS. THE HGTS ARE QUITE HIGH BETWEEN 588 AND 590 DM SO THE
MARINE LAYER WILL BE SQUASHED OUT OF THE VLYS. THE HIGH HGTS WILL
ALSO ALLOW FOR ABOVE NORMAL TEMPS OVER THE VLYS MTNS AND DESERTS.
THE NIGHT THROUGH MORNING LOW CLOUD PATTERN WILL CONTINUE OVER THE
COASTAL SECTIONS WHERE MAX TEMPS WILL BE A FEW DEGREES BELOW NORMAL.
(DOWNTOWN HAS BEEN BELOW NORMAL EVERY DAY NOW SINCE MAY 21ST OR 43
DAYS NOW)
.LONG TERM (MON-THU)...
EC AND GFS AGREE THAT PAC NW LOW WILL ROTATE THROUGH THE AREA MONDAY
THROUGH THU. NOT MUCH CHANGE MONDAY AS THE HGTS REMAIN NR 588.
ONSHORE FLOW MIGHT BE A LITTLE STRONGER WHICH WOULD HINDER BURN OFF
AT THE COAST. FROM TUESDAY ON THE TROF SETS UP OVER THE WEST COAST.
HGTS FALL TO NR 582DM AND ONSHORE FLOW INCREASES WHICH SHOULD BRING
THE MARINE LAYER INTO THE VLYS WHICH WILL LIKELY SEE 6 TO 10 DEGREES
OF COOLING AS A RESULT. COASTAL AREAS WILL NOT SEE MUCH CHANGE AND
THE INLAND AREAS WILL SEE SOME COOLING DUE TO THE LOWER HGTS.
&&
.AVIATION...
03/1100Z.
KLAX...
KBUR...
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...BRUNO
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KEKA 031048
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
348 AM PDT FRI JUL 3 2009
.SYNOPSIS...A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO MOVE ACROSS
NORTHWEST CALIFORNIA TODAY AND MAINTAIN THE THREAT OF ISOLATED
THUNDERSTORMS ACROSS TRINITY COUNTY. OVERNIGHT AND MORNING LOW
MARINE CLOUDS AND PATCHY FOG WILL CONTINUE ALONG THE COAST THROUGH
THE WEEKEND. AN UPPER LEVEL TROUGH WILL BRING AN INCREASE IN CLOUDS
AND COOLER TEMPERATURES ACROSS THE REGION NEXT WEEK.
&&
.DISCUSSION...A WEAK LOW OVER NW CA TRIGGERED THUNDERSTORMS THU
AFTERNOON JUST NE OF THE EKA FORECAST AREA...MAINLY OVER SISKIYOU
COUNTY. THE LOW WILL WEAKEN TODAY AS IT MOVES NE ACROSS THE FORECAST
AREA YET CONTINUE THE THREAT OF HIGH ELEVATION THUNDERSTORMS THIS
AFTERNOON. THE THUNDERSTORMS WILL BE ISOLATED AND DIURNAL
DRIVEN...WITH SE MID-LEVEL FLOW WILL WHISKING ANY STORMS THAT DO
DEVELOP OVER TRINITY COUNTY QUICKLY TO THE NE ACROSS SISKIYOU
COUNTY.
MARINE STRATUS AND PATCHY FOG WILL CONTINUE TO HOVER ALONG THE COAST
TODAY...AND INTO NEXT WEEK AS WINDS WILL BE LIGHT AND MIXING
LIMITED.
THE NEXT POTENTIAL WEATHER MAKER IS AN UPPER LEVEL TROUGH CURRENTLY
OVER THE NE PACIFIC NEAR 47N 145W. THIS TROUGH WILL CONTINUE TO MOVE
ACROSS THE NE PACIFIC TODAY AND SATURDAY AND NEAR NORTHWESTERN CA
SUNDAY. A SERIES OF SHORTWAVES EMBEDDED WITH IN THE TROUGH WILL MOVE
OVER THE REGION MON THROUGH WED. THIS WILL MAINTAIN A WEAK PRESSURE
GRADIENT AND SUPPORT COASTAL STRATUS INTO NEXT WEEK. ALTHOUGH TIMING
OF THE WAVES ARE STILL UNCERTAIN MODELS ARE IN FAIR AGREEMENT OF A
SHORTWAVE TROUGH AXIS MOVING OVER TRINITY COUNTY TUE AFTERNOON AND
HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS. THE MAIN IMPACTS OF
THIS TROUGH WILL BE COOLER INLAND TEMPERATURES AND AN INCREASE OF
MID LEVEL CLOUDS...AND THE POSSIBILITY OF INTERIOR CONVECTION. TH
&&
.AVIATION...AS WITH THE LAST COUPLE DAYS MARINE STRATUS CONTINUES
ALONG THE NORTH COAST. VSBYS ARE LIFR BUT WILL BECOME VFR BY MID
MORNING AS THE MARINE STRATUS LIFTS AFTER SUNRISE. CIGS WILL REMAIN
IFR AT THE COASTAL SITES. SOME PARTIAL CLEARING MAY BE SEEN LATER
THIS AFTERNOON AS THE STRATUS LAYER BURNS OFF TO NEAR THE BEACHES.
LIFR CONDITIONS WILL AGAIN RETURN AFTER SUNSET. VFR INLAND...WITH
ISOLATED THUNDERSTORMS OVER THE HIGHER TERRAIN THIS AFTERNOON AND
EVENING. NORDQUIST
&&
.MARINE...THE PRESSURE GRADIENT ALONG THE COAST HAS WEAKENED AND LOW
PRESSURE IN THE AREA WILL KEEP IT THAT WAY THROUGH THE WEEKEND. INTO
EARLY NEXT WEEK THE TIGHT PRESSURE GRADIENT REMAINS TO OUR NORTH AND
WITH THE APPROACHING UPPER LEVEL SYSTEM AT MID WEEK WILL LIKELY
STAY NORTH OF THE AREA WELL INTO MID WEEK. SEAS CONTINUE TO LAY
DOWN AND WINDS WILL REMAIN LIGHT THROUGH THE WEEKEND. A LONG PD S
SWELL AND SHORT PD NW SWELL WILL CONTINUE TO DOMINATE THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. NORDQUIST
&&
.FIRE WEATHER...THE THREAT OF ISOLATED CONVECTION CONTINUES THIS
AFTERNOON AND EARLY EVENING...WITH LIGHTNING STRIKES CAPABLE OF
INDUCING ADDITIONAL WILDFIRE STARTS. LIMITED MOISTURE ACROSS THE
REGION WILL RESULT IN VERY LIGHT RAINFALL WITH THESE STORMS AND
ISOLATED DRY LIGHTNING STRIKES ARE POSSIBLE. THUNDERSTORMS SHOULD
BE LIMITED TO EASTERN TRINITY COUNTY AND QUICKLY MOVE TO THE SE. TH
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KSTO 031027
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 AM PDT FRI JUL 03 2009
.DISCUSSION...
WEAKENING LOW OFF THE NORTHERN CALIFORNIA COAST WILL MOVE THROUGH
THE NORTHERN PORTION OF THE AREA TODAY INTO TONIGHT. LITTLE (WITHIN
A COUPLE OF DEGREES) TO NO CHANGE IS EXPECTED IN TEMPERATURES TODAY
COMPARED TO YESTERDAY. A LITTLE INSTABILITY OVER THE NORTHERN
MOUNTAINS THIS AFTERNOON (WITH A VORT MOVING THROUGH) WILL BRING
SOME CUMULUS DEVELOPMENT BUT MOST OF THE SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO STAY NORTH AND EAST OF THE AREA (WHERE THERE IS MORE
INSTABILITY). MARINE LAYER REMAINS AROUND 1800 FEET ON THE FORD ORD
PROFILER THIS MORNING. SFO-SAC SURFACE PRESSURE GRADIENT AROUND 3
MB AND SFO-VCB AROUND 4.5 MB THIS MORNING INDICATING MODERATE
ONSHORE FLOW. THIS ONSHORE GRADIENT WILL CONTINUE THE DELTA BREEZE
THROUGH THIS MORNING. THE DELTA BREEZE IS EXPECTED TO BE WEAKER
TONIGHT AS THE PRESSURE GRADIENT DECREASES.
WEAK RIDGING ON SATURDAY AHEAD OF THE TROUGH OUT IN THE NORTHEAST
PACIFIC. THIS WILL WARM THE TEMPERATURES UP A LITTLE (1 TO 3
DEGREES) FOR INDEPENDENCE DAY. ALTHOUGH THE DELTA BREEZE IS EXPECTED
TO BE WEAKER SATURDAY SO THE DELTA AREA MAY SEE A BIT MORE WARMING.
THE RIDGE WEAKENS SUNDAY AS THE TROUGH APPROACHES THE WEST COAST.
THIS WILL BE THE START OF A COOLING TREND WITH TEMPERATURES COOLING
ABOUT 5 TO 10 DEGREES COMPARED TO SATURDAY. 850MB TEMPERATURES DROP
FROM AROUND 24 DEGREES ON SATURDAY TO AROUND 20 DEGREES ON SUNDAY
INDICATING A COOLER AIR MASS. IN ADDITION...THE ONSHORE GRADIENT
WILL INCREASE ALONG WITH A DEEPENING OF THE MARINE LAYER AS THE
TROUGH APPROACHES THE COAST WHICH WILL BRING ADDITIONAL COOLING TO
THE DELTA AND ADJACENT VALLEY LOCATIONS.
THE TROUGH REMAINS OVER THE WEST COAST THROUGH AT LEAST THURSDAY
NEXT WEEK BRINGING BELOW NORMAL TEMPERATURES (HIGHS IN THE 80S IN
THE VALLEY AND 60S IN THE MOUNTAINS) AND ONSHORE FLOW. SHORT WAVES
WILL MOVE THROUGH THE TROUGH BRINGING SOME CLOUDS...ESPECIALLY OVER
THE MOUNTAINS. THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
OVER THE SHASTA COUNTY MOUNTAINS ON TUESDAY AS THE LOW MOVES INTO
THE PACIFIC NORTHWEST.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE TO PREVAIL ACROSS THE NORTHERN INTERIOR
THROUGH THE NEXT 24 HOURS...AS A WEAK SYSTEM LIFTS OVER THE REGION.
EXPECT GUSTY CONDITIONS TO ALSO CONTINUE THROUGH THE CARQUINEZ
STRAIT...WITH LOCAL GUSTS UP TO 35 KTS POSSIBLE THIS MORNING AND
AGAIN TONIGHT. LOCAL IFR CIGS MAY ALSO BE POSSIBLE WEST OF KSUU
UNTIL 16Z. SOME CUMULUS MAY DEVELOP OVER COASTAL MTNS AND
SHASTA/WRN PLUMAS COUNTIES THIS AFTERNOON /AFT 19Z-20Z/...BUT
CONVECTION EXPECTED TO BE FURTHER E AND WELL INTO NV.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KREV 031013
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
312 AM PDT FRI JUL 3 2009
.SHORT TERM...
ONE MORE DAY OF CONVECTION BEFORE QUIET WEATHER RETURNS TO THE
REGION. MOISTURE AND LLVL INSTABILITY COMBINED TO PRODUCE STRONG TO
SEVERE TSTMS AND LOCALLY HEAVY RAINFALL THURSDAY AFTN AND EVENING
ACROSS THE KREV CWFA.
MOISTURE IS STILL IN PLACE ACROSS THE REGION AND MOSTLY SUNNY SKIES
AND WARM SFC TEMPERATURES WILL AGAIN DESTABILIZE THE LOWER
ATMOSPHERE AND HELP TO PRODUCE TSTMS THIS AFTN AND EVENING.
HOWEVER...THE UPPER LEVEL WINDS HAVE TURNED TO MORE WLY AND THIS
WILL HELP TO PUSH THE CONVECTION TO THE EAST AS THE EVENING
PROGRESSES.
THE INDEPENDENCE DAY WEEKEND WILL BE DRY WITH SEASONABLY WARM
TEMPERATURES. AFTN HIGHS BOTH SATURDAY AND SUNDAY WILL BE IN THE
MIDDLE TO UPPER 90S IN WRN NEVADA WITH READINGS IN THE 80S IN THE
SIERRA. WINDS COULD BE GUSTY STARTING SUNDAY AFTN AS AN UPPER LEVEL
TROUGH APPROACHES THE NRN CALIFORNIA COAST. O`HARA
.LONG TERM...MONDAY THROUGH THURSDAY...
TROUGH LIKELY TO REMAIN OVER THE WEST UNTIL THE END OF THE WEEK.
WITH THE MAIN LOW OVER THE PACIFIC NORTHWEST...A DRY AND STABLE
SOUTHWEST FLOW WOULD SET UP OVER THE AREA. BREEZY TO WINDY
AFTERNOONS AND EVENINGS ARE COMMON DURING THIS TYPE OF PATTERN.
TEMPERATURES SHOULD BE NEAR TO BELOW NORMAL THROUGH THE PERIOD.
MONDAY AND TUESDAY LOOK TO BE THE DAYS WITH THE HIGHEST WINDS AS A
JET SEGMENT AND WAVE PASS OVER THE NORTHERN AREAS. GUSTS 30-45 MPH
POSSIBLE WITH LOW TO VERY LOW AFTERNOON HUMIDITY DESPITE THE COOLER
TEMPERATURES. MODELS SHOW THE FLOW ALOFT RELAXES A BIT FOR
WEDNESDAY AND THURSDAY...BUT POSITION OF LOW IS STILL FAVORABLE FOR
SHORT WAVE ENERGY TO AFFECT THE AREA AND MAINTAIN THE GUSTY WINDS.
BRONG
&&
.AVIATION...
STABLE SOUTHWEST FLOW WILL KEEP THUNDERSTORMS AWAY FROM RENO-TAHOE
TODAY. ISOLATED THUNDERSTORMS ARE POSSIBLE TODAY ARE FOR AREAS
NORTH AND EAST OF SUSANVILLE-FERNLEY-BRIDGEPORT LINE.
STRONGER TROUGH SET TO APPROACH THE WEST COAST SATURDAY AND REMAIN
STATIONARY ALONG THE COAST THROUGH NEXT WEEK. WINDS LIKELY TO
INCREASE WITH AFTERNOON GUSTS NEAR 35 KTS POSSIBLE MOST AREAS NEXT
WEEK. BRONG
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSGX 030940
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
300 AM PDT FRI JUL 3 2009
.SYNOPSIS...FAIR WEATHER WILL CONTINUE EXCEPT FOR JUST A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE MOUNTAINS AND DESERTS THIS
AFTERNOON. A SHALLOW MARINE LAYER WILL CONTINUE TO BRING LOW CLOUDS
AND FOG NEAR THE COAST EACH NIGHT AND MORNING THROUGH THE HOLIDAY
WEEKEND. HIGH PRESSURE WILL GRADUALLY WEAKEN NEXT WEEK BRINGING
COOLER WEATHER WITH MORE EXTENSIVE LOW CLOUDS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
SKIES WERE MOSTLY CLEAR THIS MORNING WITH SOME LOW CLOUDS NEAR THE
COAST MOVING INLAND. THESE LOW CLOUDS COULD PUSH INTO THE CORNERS OF
THE INLAND EMPIRE BY SUNRISE. THIS AFTERNOON SOME CUMULUS WILL
DEVELOP IN THE MOUNTAINS AND DESERTS WITH AN ISOLATED THUNDERSTORM
POSSIBLE. OTHERWISE MORE OF THE SAME WEATHER IS EXPECTED THROUGH THE
HOLIDAY WEEKEND WITH MOSTLY SUNNY DAYS AND WARM SEASONAL WEATHER. A
TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE WEST COAST AND HEIGHTS
OVER SOUTHERN CALIFORNIA WILL DIP SLIGHTLY. THIS WILL MEAN A DEEPER
MARINE LAYER WITH MORE EXTENSIVE LOW CLOUDS AND COOLER WEATHER FOR
ALL AREAS MONDAY THROUGH THURSDAY. THE UPPER HIGH OVER THE SOUTHWEST
APPEARS TO EXPAND AGAIN BY NEXT FRIDAY TO INCREASE TEMPERATURES
AGAIN AND SQUASH THE MARINE INFLUENCE. THE TIMING FOR THESE DETAILS
IS NOT LOCKED IN AS MODELS DIFFER A BIT ON WHEN WARMING OR COOLING
TRENDS BEGIN AND END.
&&
.AVIATION...
030900Z...MARINE LAYER DEPTH THIS MORNING WAS AROUND 1500 FEET.
MARINE LAYER SHOULD LOWER TO AROUND 1000 FEET OR LESS TONIGHT AND
SATURDAY. AREAS OF STRATUS WITH BASES AROUND 1000 FEET MSL ALONG THE
IMMEDIATE COAST AND LOCALLY INTO THE INLAND VALLEY AREAS SHOULD
BREAK UP BETWEEN 15Z AND 17Z. EXPECT STRATUS TO RETURN TO THE
IMMEDIATE COAST BY SUNSET AND SPREAD LOCALLY INLAND BETWEEN 05Z AND
08Z. COULD BE VLIFR CONDITIONS AT SOME COASTAL AIRPORTS SUCH AS KCRQ
BETWEEN 08Z AND SUNRISE SATURDAY MORNING AND CEILINGS AT KSAN COULD
GO BELOW LOCALIZER RNWY 27 MINIMUMS BEFORE SUNRISE ON SATURDAY AS
WELL.
ABOVE THE MARINE LAYER...SCATTERED CU/ISOLATED TCU/CBS/TSTMS WITH
BASES AT OR ABOVE FL090 AND TOPS TO OR ABOVE FL350 AT TIMES ARE
EXPECTED OVER THE MOUNTAINS DURING THE AFTERNOON...OTHERWISE A
MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES WILL CONTINUE
THROUGH SATURDAY. HORTON
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MM
AVIATION...HORTON
000
FXUS66 KHNX 030833
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
133 AM PDT FRI JUL 3 2009
.DISCUSSION...DRY AND STABLE AIR HAS SPREAD OVER THE AREA AS THE
SHORTWAVE TROUGH HAS PUSHED INTO CALIFORNIA. THIS HAS ELIMINATED THE
THREAT OF THUNDERSTORMS OVER THE SIERRA AND KERN COUNTY DESERTS
AND MOUNTAINS AND THE DRY FLOW WILL CONTINUE FOR THE NEXT SEVERAL
DAYS AT LEAST. FORECAST MODELS KEEP THE TROUGH OVER CALIFORNIA
TODAY AND THEN KEEP A DRY SOUTHWEST FLOW IN PLACE OVER THE
WEEKEND. LITTLE CHANGE IN HEIGHTS IS PROJECTED, THUS TEMPERATURES
WILL SHOW LITTLE DAY TO DAY CHANGE THROUGH SUNDAY. BY MONDAY BOTH
THE GFS AND ECMWF MODELS PUSH THE NEXT PACIFIC LOW PRESSURE SYSTEM
TOWARD THE WASHINGTON COAST HOWEVER THE GFS CONTINUES TO PROJECT
THIS FEATURE DEEPER THAN THE ECMWF. THROUGH MID WEEK THE LOW IS
PROJECTED TO STALL OUT OVER THE PACIFIC NORTHWEST AND A ROBUST
ONSHORE FLOW WILL ENSUE. GIVEN THIS, TEMPERATURES WILL COOL
CONSIDERABLY OVER THE CENTRAL CALIFORNIA INTERIOR TO LEVELS BELOW
NORMAL.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA
INTERIOR THROUGH 12Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 3 2009...UNHEALTHY IN KERN COUNTY. UNHEALTHY FOR
SENSITIVE GROUPS IN FRESNO... KINGS... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...DUDLEY
AVN/FW...DS
WEATHER.GOV/HANFORD
000
FXUS66 KLOX 030630
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
833 PM PDT THU JUL 2 2009
.SYNOPSIS...SEASONAL CONDITIONS WILL CONTINUE THROUGH THE WEEKEND
AS A RIDGE OF HIGH PRESSURE WEAKENS. AN UPPER TROUGH WILL BECOME
ESTABLISHED OVER THE WEST COAST NEXT WEEK...BRINGING A COOLING
TREND AND A DEEPENING MARINE LAYER.
&&
.UPDATE...A DRIER SOUTHWEST FLOW ALOFT CONTINUES TO ESTABLISH OVER
THE AREA AS A RIDGE OF HIGH PRESSURE OVER DESERT SOUTHWEST WEAKENS
AND CONTINUES TO MOVE EAST. ALL CONVECTIVE STORMS REMAINED WELL
EAST OF THE AREA WITH ONLY A FEW FLAT CUMULUS CLOUDS OVER THE
HIGHER TERRAIN.
FROM THE LATEST ACARS SOUNDINGS...THE MARINE LAYER IS SLIGHTLY
DEEPER THAN LAST NIGHT...AROUND 1100 FEET THIS EVENING. NAM-WRF
SOLUTIONS ARE ARRIVING THIS EVENING AND MODEL SURFACE GRADIENTS
ARE WELL-INITIALIZED. HOWEVER...THE 950 MB TEMPERATURES ARE ABOUT
TWO DEGREES CELSIUS TOO WARM VERSUS ACARS AND RADIOSONDE
SOUNDINGS. NAM-WRF SOLUTIONS ARE WARMING TEMPERATURES AT 950 MB
INDICATING A POSSIBILITY OF A FEW DEGREES WARMING OVER THE INLAND
AREAS. HOWEVER WITH A OPEN WAVE TROUGH TO THE NORTHWEST...SURFACE
GRADIENTS CHANGING VERY LITTLE...AND A SOUTHWEST FLOW ALOFT IN
PLACE...THERE IS SOME DOUBT IN A WARMING TREND ACTUALLY OCCURRING
ON FRIDAY. AS A RESULT...THE PACKAGE FOR FRIDAY WILL REMAIN
UNCHANGED.
FOR THE REST OF THE WEEKEND...SOUTHWEST FLOW ALOFT AND A
DEVELOPING UPPER-LEVEL TROUGH OVER THE NORTHEASTERN PACIFIC WILL
LIKELY KEEP AN ONSHORE FLOW PATTERN IN PLACE OVER THE AREA
THROUGHOUT THE PERIOD. TEMPERATURES WILL BE NEAR SEASONAL NORMALS
FOR THE WEEKEND WITH A CONTINUED MARINE LAYER PRESENCE AT THE
COASTAL AREAS.
&&
.PREV DISCUSSION... /ISSUED 440 PM PDT THU JUL 2 2009/
LONG TERM...FOR EXTENDED...MODELS ON SAME SYNOPTIC PAGE
INDICATING A VERY BLAND PATTERN FOR THE AREA. AT UPPER LEVELS...
TROUGH WILL BECOME ESTABLISHED OVER THE WEST COAST...WITH
SOUTHWEST FLOW PREVAILING OVER OUR AREA. NEAR THE SURFACE...CAN
ANTICIPATE CONTINUED ONSHORE FLOW WITH A GRADUAL DEEPENING OF THE
MARINE LAYER.
WITH THE ABOVE PATTERN...EXPECT A TYPICAL MARINE LAYER FORECAST
FOR THE AREA...WITH NO CONCERN ABOUT ANY MONSOONAL MOISTURE. AS
FOR TEMPS...EXPECT SLIGHTLY COOLER CONDITIONS WITH MOST AREAS
AT OR A FEW DEGREES BELOW SEASONAL NORMS.
&&
.AVIATION...
03/0630Z.
1000 FOOT MARINE LAYER WILL ALLOW GRADUAL FORMATION OF IFR CIGS
ACROSS ALL COASTAL SITES OVERNIGHT. TOTAL CLEARING IS LIKELY FOR ALL
SITES FRIDAY BY LATE MORNING. NO WIND ISSUES.
KLAX...FAIR CONFIDENCE IN TAF. THERE IS A 40 PERCENT CHANCE THE CIGS
COULD RETREAT JUST OFFSHORE FROM 06Z-12Z.
KBUR...VERY GOOD CONFIDENCE IN VFR TAF.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HALL/SETO
PUBLIC...HALL/THOMPSON
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 030533
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
851 PM PDT THU JUL 2 2009
.DISCUSSION...AS OF 8:51 PM PDT THURSDAY...OVERALL TEMPERATURES WERE
QUITE SIMILAR TO THOSE ON WEDNESDAY ACROSS THE DISTRICT WITH HIGHS
RANGING FROM THE UPPER 50S NEAR THE OCEAN TO THE 60S TO 80S INLAND.
THE HOTTEST INLAND AREAS WERE A LITTLE WARMER...SOME IN FAR SOUTHERN
MONTEREY COUNTY TOPPING OUT OVER 100 DEGREES. SATELLITE IMAGERY
SHOWS STRATUS ALONG THE COAST...AND THE ONSHORE SURFACE PRESSURE
GRADIENT IS STRONG WITH 3.5 MB BETWEEN SFO AND SAC LAST HOUR. THE
FORT ORD PROFILER INDICATES A MARINE LAYER DEPTH OF AROUND 1600
FEET. EXPECT LOW CLOUDS TO MOVE INLAND ONCE AGAIN TONIGHT.
MODELS SLOWLY BRING AN UPPER LEVEL TROUGH TOWARDS THE COAST OVER THE
NEXT FEW DAYS FOR A GRADUAL COOLING TREND EXPECTED ACROSS THE
DISTRICT BY EARLY NEXT WEEK. AN UPPER TROUGH IS THEN FORECAST TO
REMAIN ALONG THE WEST COAST THROUGH NEXT WEEK FOR CONTINUED COOL
TEMPS ALONG WITH NIGHT AND MORNING STRATUS. CURRENT FORECASTS LOOK
ON TRACK...NO UPDATES EXPECTED AT THIS TIME.
&&
.AVIATION...AS OF 10:30 PM PDT THURSDAY...STRATUS IS STARTING TO
FILTR INTO SFO AND MRY BAY. BASES WILL BE BELOW 1000 FEET NEAR THE
COAST AND 1000-1200 FEET INLAND.
VICINITY OF KSFO...STRATUS SPREADING THTROUGH THE GAPS WILL MOVE
OVER SFO BY 09Z AND STAY THROUGH 17-18Z WITH BASES AROUND
1000-1200 FEET.
KSFO BRIDGE APPROACH...STRATUS WILL AFFECT THE APPROACH AFTER 08Z.
BASES EXPECTED TO BE AROUND 1000-1200 FEET. CLEARING BY 18Z.
MONTEREY BAY TERMINALS...STRATUS GRADUALLY SPREADING OVER ALL OF
MRY BAY WITH CEILINGS STARTING OUT AT 1000-1500 FEET BEFORE LOWERING
TO 500-1000 FEET A COUPLE OF HOURS LATER. CLEARING BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: SSA
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 030500
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 PM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
STORM ACTIVITY HAS TRAILED OFF CONSIDERABLY AND ONLY WEAK ISOLATED
STORMS ARE LEFT OVER ARIZONA AND SOUTHEAST CALIFORNIA. THERE IS A
CONSIDERABLE AMOUNT OF MOISTURE AROUND WITH PRECIPITABLE WATER
VALUES OF 1.4-1.7 INCHES ON THE LOWER ELEVATIONS. HOWEVER...00Z AND
03Z PSR SOUNDINGS SHOW WARM MID LEVELS INHIBITING INSTABILITY. IF A
DISTURBANCE CAN MOVE THROUGH TONIGHT AS INDICATED BY THE RUC THEN A
NOCTURNAL PRECIP EVENT IS STILL POSSIBLE...THOUGH IT ONLY ADVERTISES
A BRUSH-BY FOR EASTERN ZONE 24 AFTER 12Z. IF THIS FEATURE HAD
SUFFICIENT LIFT WOULD ALSO EXPECT TO SEE MORE STORM ACTIVITY OVER
SOUTHEAST ARIZONA BY NOW. GFS AND NAM ARE NOT DEPICTING ANY COHERENT
FEATURES CREATING PROLONGED VERTICAL MOTIONS. WILL HANG ON TO
LINGERING SLIGHT CHANCES BUT WITH SOME MODIFICATIONS.
MODELS MAINTAIN FAIRLY HIGH MOISTURE VALUES THROUGH THE WEEKEND
BEFORE BEGINNING TO DRY FROM THE WEST. NEITHER GFS NOR NAM INDICATE
BIG IMPROVEMENTS TO INSTABILITY PER FORECAST SOUNDINGS. SO IT WILL
BE DIFFICULT TO PINPOINT ANY LARGE UPSWINGS OR DOWNSWINGS OVER THE
NEXT 2-3 DAYS.
PREVIOUS DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS66 KHNX 030456
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
956 PM PDT THU JUL 2 2009
.UPDATE...NO UPDATE REQUIRED
&&
.DISCUSSION...WEAK SHORTWAVE ENERGY IS SUPPRESSING THE WESTERN US
RIDGE AND KEEPING HIGH TEMPERATURES FROM GETTING EXCESSIVELY HOT
ACROSS INTERIOR CENTRAL CALIFORNIA...GENERALLY RUNNING ABOUT 5
DEGREES ABOVE CLIMO. SOUTHWESTERLY FLOW KEPT AFTERNOON AND EVENING
CONVECTION EAST OF THE SIERRA CREST TODAY. THIS GENERAL PATTERN
WILL CONTINUE THROUGH THE HOLIDAY WEEKEND. A DEVELOPING TROUGH
MOVING ONSHORE THE WEST COAST WILL THEN BRING A COOLING TREND TO
THE DISTRICT EARLY NEXT WEEK. OTHER THAN REMOVING EVENING
CONVECTION FROM THE SIERRA ZONES...NO UPDATE IS REQUIRED FOR THE
FORECAST TONIGHT.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA
INTERIOR THROUGH 06Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON FRIDAY JULY 3 2009... UNHEALTHY IN KERN COUNTY. UNHEALTHY FOR
SENSITIVE GROUPS IN FRESNO... KINGS... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...JEB
AVN/FW...MOLINA
WEATHER.GOV/HANFORD
000
FXUS65 KREV 030440
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
940 PM PDT THU JUL 2 2009
.UPDATE...
CONVECTION WAS WINDING DOWN THIS EVENING AFTER BECOMING FAIRLY
ACTIVE OVER THE SOUTHEAST HALF OF THE CWA DURING THE AFTERNOON AND
EARLY EVENING. THE PRIMARY THREAT WITH TODAYS THUNDERSTORMS WAS
HEAVY RAIN...AT LEAST BASED ON THE REPORTS THAT CAME IN. WATER
OVER ROADWAYS WAS REPORTED BY CAL TRANS NEAR OASIS IN SOUTHEAST
MONO COUNTY LATE THIS AFTERNOON WHILE WEATHER SPOTTERS REPORTED HEAVY
RAIN (WITH SOME STREET FLOODING) PRECEDED BY BLOWING DUST FROM
HAZEN TO FERNLEY THIS EVENING. SOME OF THE STRONGER STORMS SHOWN
ON RADAR THIS AFTN/EVE COULD NOT BE VERIFIED AS THEY TRAVELED OVER
SPARSELY POPULATED AREAS. BASED ON THE LATEST RADAR
TRENDS...FORECASTS HAVE BEEN UPDATED TO REMOVE MENTION OF
THUNDERSTORMS FROM MOST ZONES TONIGHT...THE EXCEPTION BEING
MINERAL COUNTY NORTH THROUGH PERSHING COUNTY. RC
&&
.PREVIOUS DISCUSSION... /ISSUED 324 PM PDT THU JUL 2 2009/
SHORT TERM...
CONVECTION HAS BEEN MORE ACTIVE TODAY FROM RENO-TAHOE SEWD ACROSS
DOUGLAS-LYON-MINERAL COUNTIES. STRONGEST CELLS FORMED IN RURAL
PORTIONS OF MINERAL COUNTY SO FAR THIS AFTERNOON. WINDS AT SLIDE
MTN FINALLY SWITCHED TO WEST IN PAST HOUR AS THE BACK EDGE OF
CONVECTION APPEARS TO HAVE PUSHED EAST OF TRUCKEE...WHILE FARTHER
SOUTH IN MONO COUNTY ONLY A FEW CELLS REMAIN EAST OF HWY 395.
GUSTY OUTFLOW WINDS WILL REMAIN A THREAT THRU EARLY EVENING
ESPECIALLY IN W-CNTRL NV NORTH OF HWY 50 WHERE DRIER LOW LEVEL AIR
MASS WILL INCREASE DOWNDRAFT MOMENTUM FROM ANY CELLS MOVING INTO
THIS AREA.
MOST ACTIVITY SHOULD DIMINISH AFTER SUNSET AS THE WEAK SHORTWAVE
TROF RESPONSIBLE FOR THE TSTMS EJECTS TO THE NORTHEAST...ALTHOUGH
SOME INSTBY IS EXPECTED TO PUSH INTO FAR NWRN NV AND SURPRISE VLY
OVERNIGHT AND FRI MORNING SO ISOLD TSTMS WERE MAINTAINED IN THOSE
AREAS.
FOR FRIDAY...REDUCED COVERAGE OF CONVECTION IS EXPECTED ALTHOUGH
STUBBORN WEAK LOW OVER NRN CA WILL KEEP THREAT OF SOME ACTIVITY
OVER FAR NERN CA AND NWRN NV. FARTHER SOUTH TO MINERAL-MONO
COUNTIES...A FEW SHORT LIVED CELLS ARE POSSIBLE...BUT ANYTHING
THAT FORMS WILL BE LESS INTENSE COMPARED TO TODAY. WITH DRIER AND
MORE STABLE AIR MASS ADVANCING INTO THE RENO-TAHOE ZONES AND NO
FORCING MECHANISMS INDICATED BY THE NAM AND GFS GUIDANCE...THE
MENTION OF TSTMS WAS REMOVED FOR THESE AREAS.
FOR THE INDEPENDENCE DAY WEEKEND...DRY AND WARM CONDITIONS ARE
EXPECTED ACROSS THE REGION AS SW FLOW ALOFT PREVAILS WITH LITTLE
OR NO DYNAMIC FORCING. SOME LEFTOVER MID LEVEL MOISTURE WILL LEAD
TO SOME CUMULUS BUILDUPS SAT AFTERNOON MAINLY IN MINERAL-MONO
COUNTIES AND ALSO NEAR THE OREGON BORDER...BUT WARMER AIR ALOFT
SHOULD CAP VERTICAL CLOUD GROWTH. WHILE A BRIEF SHOWER CAN NOT BE
RULED OUT...THIS POTENTIAL IS TOO REMOTE TO INCLUDE IN THE
FORECAST TEXT. WINDS ON SATURDAY THE 4TH SHOULD BE ZEPHYR TYPE
BREEZES WITH GUSTS NEAR 25 MPH...WHICH MAY PERSIST UNTIL ABOUT 10
PM FOR THE RENO-SPARKS-CARSON AREAS BUT SHOULD DIMINISH BY DUSK
AROUND TAHOE. FOR SUNDAY...WIND GUSTS WILL INCREASE TO THE 30-35
MPH RANGE AS WEAK SHORTWAVE MOVING INTO THE NWRN US BRUSHES
ACROSS NERN CA-NWRN NV. MJD
LONG TERM...MONDAY THROUGH THURSDAY...
THE MAIN CHANGES TO THE LONG TERM GRIDS WERE TO LOWER SKY COVER
(EXCEPT ACROSS THE FAR NORTHERN CWA) AND RELATIVE HUMIDITIES.
A LARGE-SCALE UPPER TROUGH WILL BE HANGING AROUND ALONG THE WEST
COAST OR SLIGHTLY OFFSHORE THROUGH THE EXTENDED...WITH AN IMPULSE
EJECTING AROUND THE MAIN TROUGH LATE TUESDAY (GFS) OR WEDNESDAY
(ECMWF). THE IMPULSE WOULD AT MOST BRING A FEW SHOWERS TO THE FAR
NORTH...WITH VERY DRY SOUTHWEST FLOW ELSEWHERE TO WARD OFF
PRECIPITATION. THE MAIN STORY WILL BE THE COOLING TREND...WITH 70S
TO MID 80S IN THE VALLEYS TUESDAY THROUGH THURSDAY (5-10 DEGREES
BELOW AVERAGE). IT WILL ALSO TEND TO BE BREEZY WITH THE PERSISTENT
GRADIENT BETWEEN THE UPPER TROUGH AND A RIDGE OVER THE DESERT
SOUTHWEST. SNYDER
AVIATION...
LIGHTER WINDS ALOFT THAN EXPECTED AND AN INCOMING DISTURBANCE ARE
ALLOWING SHOWERS AND THUNDERSTORMS TO DEVELOP FURTHER WEST THAN
PREVIOUSLY EXPECTED...WITH A LINE OF CONVECTION IN THE AREA OF
KTVL/KTRK/KRNO TO MOVE EAST OF KRNO (AND AFFECT THE AREA OF KLOL)
CIRCA 01Z. ALL STORMS COULD PRODUCE GUSTY OUTFLOW WINDS...BUT THE
MAIN RISK FOR VERY GUSTY OUTFLOW WINDS WILL BE EAST OF KRNO AND FROM
ABOUT KNFL NORTH...WHERE STRONGER STORMS COULD PRODUCE GUSTS TO
40-45 KTS AND VERY HEAVY RAIN.
FRIDAY...ANY THUNDERSTORMS SHOULD BE RESTRICTED TO NORTH AND EAST OF
A SUSANVILLE TO FALLON TO BRIDGEPORT LINE. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSTO 030437
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 PM PDT THU JUL 02 2009
.DISCUSSION...
SHORT WAVE THAT WE NOTICED LIFTING NEWD FROM THE BASE OF THE
OFFSHORE UPPER TROF LAST EVENING HAS MOVED INTO WRN NV FASTER THAN
PROGGED LAST EVENING. STORMS DEVELOPED AROUND 20Z ON THE E SIDE OF
THE SIERNEV CREST GENERALLY FROM THE TAHOE AREA SWD AND QUICKLY
MOVED NEWD WITH THE MEAN FLOW. THE SHORT WAVE ALSO LIFTED THE
DEFORMATION ZONE NEAR THE CA/OR BORDER A LITTLE FURTHER NWD AND
STORMS FROM THAT FEATURE WERE FURTHER FROM OUR AREA THAN THEY WERE
YESTERDAY. THE SHORT WAVE THAT PASSED THRU THE AREA TODAY DID BRING
ABOUT 2 TO 3 DEGREES OF COOLING TO THE INTERIOR VLY AS THE MARINE
AIR SPREAD A LITTLE FURTHER NWD...UP TO CHICO/RED BLUFF THANKS TO A
STRONGER UP VALLEY GRADIENT THAN YESTERDAY...AND TO THE W SLOPE
SIERNEV MAINLY S OF I-80.
FOR FRI...EVEN LESS OF A CHANCE OF DEEP CONVECTION IN OUR CWA IS
EXPECTED AS THE OFFSHORE UPPER LOW CONTINUES TO FILL AND BENIGN SWLY
FLOW PREVAILS OVER THE REGION. WE EXPECT TEMPS TO FOLLOW RATHER
CLOSE TO PERSISTENCE ON FRI WITH NO SIGNIFICANT THERMAL CHANGES
FORECAST. WITH THE UPPER LOW FILLING AS IT MOVES INLAND...SHORT WAVE
RIDGING WILL OCCUR ON SAT AHEAD OF THE GULF OF AK/NERN PAC TROF.
THIS FEATURE WILL AFFECT NORCAL WX DURING THE LATE IN THE WEEKEND
AND EARLY NEXT WEEK. SOME MODEST WARMING IS EXPECTED ON THE 4TH OF
JULY HOLIDAY...AS THE DELTA BREEZE WEAKENS. ALL-IN-ALL VERY NICE
SEASONABLE WX FOR THE INTERIOR OF NORCAL OVER THE LONG HOLIDAY
WEEKEND. JHM
.PREVIOUS DISCUSSION...
COOLING TREND BEGINS SUNDAY AS THE UPPER LOW LIFTS TOWARDS THE PACNW
AND ONSHORE FLOW OVER NORCAL INCREASES. COOLING CONTINUES THROUGH
THE MIDDLE OF NEXT WEEK AS LONG WAVE TROUGH BECOMES ESTABLISHED
ALONG THE WEST COAST AND ADDITIONAL SHORT WAVES MOVE THROUGH.
PCH
.EXTENDED DISCUSSION (MONDAY THRU THURSDAY)...
LONGWAVE TROUGH IN PLACE OVER THE ERN PACIFIC THROUGH THE EXTENDED.
SHORT WAVE TROUGHS WILL PROPAGATE INTO THE PACIFIC NW AND EXTREME
NRN CAL. THE FIRST SHORTWAVE WITH A NEUTRAL TILT WILL IMPACT THE
NRN MTNS TUE. THEREFORE WE HAVE INCREASED THE POPS FOR THE AFTN AND
EVENING AND ADDED A SLIGHT CHANCE OF THUNDERSTORMS. TWO WEAKER
POSITIVELY TILTED TROUGHS WILL PROGRESS THROUGH NRN CAL WED AND THU
BUT ONLY GENERATE SOME ENHANCED CUMULUS OVER THE TERRAIN. THIS
PERSISTENT TROUGHING WILL KEEP DAYTIME TEMPS BELOW NORMAL AND AN
ONSHORE WIND REGIME. NORMAL TEMPS FOR NEXT WEEK ARE 96 TO 98 FOR
RED BLUFF AND REDDING...AND 91 TO 94 FROM SACRAMENTO TO MODESTO.
THE MARINE LAYER STRATUS WILL PERSIST AND TEND TO DEEPEN IN RESPONSE
TO THE UPPER LEVEL TROUGH INSIDE OF 130W. JMC
&&
.AVIATION...
VFR SKC CONDITIONS OVER INTERIOR NORCAL TONIGHT EXCEPT FOR LOCAL IFR
CIGS POSSIBLE DUE TO STRATUS WEST OF TRAVIS 08Z-16Z. DELTA BREEZE
EXPECTED TO CONTINUE 20-30 KTS THROUGH CARQUINEZ STRAIT OVERNITE.
POSSIBLE CUMULUS OVER COASTAL MTNS AND SHASTA/WRN PLUMAS COUNTIES
FRI AFTERNOON /AFT 19Z-20Z/...BUT CONVECTION EXPECTED TO BE FURTHER
E AND WELL INTO NV MORE SO THAN TODAY FROM TAHOE AREA SWD.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KSGX 030357
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
900 PM PDT THU JUL 2 2009
.SYNOPSIS...FAIR WEATHER WILL CONTINUE EXCEPT FOR JUST A SLIGHT
CHANCE OF THUNDERSTORMS OVER THE MOUNTAINS AND DESERTS FRIDAY
AFTERNOON. A SHALLOW MARINE LAYER WILL CONTINUE TO BRING LOW CLOUDS
AND FOG NEAR THE COAST EACH NIGHT AND MORNING. FAIR AND WARM WITH
NEAR NORMAL TEMPERATURES THIS WEEKEND THOUGH NEXT WEEK.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
AN OUTFLOW BOUNDARY ORIGINATING FROM AFTERNOON CONVECTION NEAR LAS
VEGAS MANAGED TO TRIGGER SOME THUNDERSTORMS JUST EAST OF OUR UPPER
DESERTS THIS EVENING BUT NONE ENTERED OUR AREA. NO FURTHER ACTIVITY
IS EXPECTED TONIGHT. MOIST SOUTHERLY FLOW AND WEAK INSTABILITY IN
THE MID LEVELS WILL BRING JUST A SLIGHT CHANCE OF SCATTERED SHOWERS
OR TSTORMS FRI AFTERNOON IN THE MOUNTAINS AND DESERTS. DRY SEASONAL
WEATHER IS EXPECTED FOR THE HOLIDAY WEEKEND THROUGH TUE OF NEXT WEEK
AS A 592 UPPER HIGH RESTS OVER SOCAL AND THE DESERT SW. HEIGHTS
DECREASE WED-THU AS WESTERLY FLOW INCREASES ALOFT FOR SLIGHT COOLING
INLAND. NIGHT AND MORNING LOW CLOUDS AND FOG WILL CONTINUE MAINLY IN
THE COASTAL ZONES. THE DESERT SW UPPER HIGH INTENSIFIES OVER SW CA
LATE NEXT WEEK THROUGH THE FOLLOWING WEEKEND FOR SLIGHT WARMING
INLAND. MODELS HINT AT A POSSIBLE EASTERLY WAVE COMING IN FROM
MEXICO BY SUN JUL 12.
&&
.AVIATION...
030300Z...MARINE LAYER ABOUT 1500 FT. BASES AROUND 1K FT MSL. VSBY
ABOVE 7SM WITH AREAS 3-5SM AND ISOLATED 1-2SM OR LOWER IN THE
FOOTHILLS IN THE MORNING. STRATUS AND FOG ALONG THE SAN DIEGO COUNTY
COAST...SPREADING INLAND TO THE SAN DIEGO COUNTY INLAND VALLEYS AND
MOSTLY SOUTHERN ORANGE COUNTY COAST LATE TONIGHT THROUGH FRIDAY
MORNING. STRATUS AND FOG DISSIPATING 16-18Z WITH AREAS OF STRATUS
REMAINING ALONG THE SAN DIEGO COUNTY COAST AFTERNOON. MARINE LAYER
EXPECTED TO DECREASE TO ABOUT 1200 FT WITH LOWER BASES AND VSBY NEAR
THE COAST FRIDAY NIGHT. SCATTERED TO BROKEN CUMULUS OVER THE
MOUNTAINS AND DESERTS FRIDAY AFTERNOON AROUND 13K FT WITH A VERY
SLIM CHANCE FOR THUNDERSTORMS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MACKECHNIE
AVIATION...WHITLOW
000
FXUS66 KMTR 030351
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
851 PM PDT THU JUL 2 2009
.DISCUSSION...AS OF 8:51 PM PDT THURSDAY...OVERALL TEMPERATURES WERE
QUITE SIMILAR TO THOSE ON WEDNESDAY ACROSS THE DISTRICT WITH HIGHS
RANGING FROM THE UPPER 50S NEAR THE OCEAN TO THE 60S TO 80S INLAND.
THE HOTTEST INLAND AREAS WERE A LITTLE WARMER...SOME IN FAR SOUTHERN
MONTEREY COUNTY TOPPING OUT OVER 100 DEGREES. SATELLITE IMAGERY
SHOWS STRATUS ALONG THE COAST...AND THE ONSHORE SURFACE PRESSURE
GRADIENT IS STRONG WITH 3.5 MB BETWEEN SFO AND SAC LAST HOUR. THE
FORT ORD PROFILER INDICATES A MARINE LAYER DEPTH OF AROUND 1600
FEET. EXPECT LOW CLOUDS TO MOVE INLAND ONCE AGAIN TONIGHT.
MODELS SLOWLY BRING AN UPPER LEVEL TROUGH TOWARDS THE COAST OVER THE
NEXT FEW DAYS FOR A GRADUAL COOLING TREND EXPECTED ACROSS THE
DISTRICT BY EARLY NEXT WEEK. AN UPPER TROUGH IS THEN FORECAST TO
REMAIN ALONG THE WEST COAST THROUGH NEXT WEEK FOR CONTINUED COOL
TEMPS ALONG WITH NIGHT AND MORNING STRATUS. CURRENT FORECASTS LOOK
ON TRACK...NO UPDATES EXPECTED AT THIS TIME.
&&
.AVIATION...AS OF 4:30 PM PDT THURSDAY...STRATUS HAS RETREATED
AWAY FROM THE IMMEDIATE COAST. SOUTHWESTERLY FLOW WILL BRING
LOW CEILINGS BACK ONSHORE LATER TONIGHT.
VICINITY OF KSFO...SOUTHWESTERLY FLOW WILL KEEP VFR CONDITIONS
THROUGH THE AIRPORT EVENING RUSH HOUR. LOW CEILINGS WILL SPREAD
OVER THE AIRPORT AFTER MIDNIGHT AND STAY THROUGH 17-18Z WITH BASES
AROUND 1000-1200 FEET.
KSFO BRIDGE APPROACH...STRATUS WILL STAY OUT UNTIL AT LEAST 08Z.
BASES EXPECTED TO BE AROUND 1000-1200 FEET. CLEARING BY 18Z.
MONTEREY BAY TERMINALS...STRATUS WILL RETURN BY 04Z WITH CEILINGS
STARTING OUT AT 1000-1500 FEET BEFORE LOWERING TO 500-1000 FEET A
COUPLE OF HOURS LATER. CLEARING BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: SSA
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 030333
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
833 PM PDT THU JUL 2 2009
.SYNOPSIS...SEASONAL CONDITIONS WILL CONTINUE THROUGH THE WEEKEND
AS A RIDGE OF HIGH PRESSURE WEAKENS. AN UPPER TROUGH WILL BECOME
ESTABLISHED OVER THE WEST COAST NEXT WEEK...BRINGING A COOLING
TREND AND A DEEPENING MARINE LAYER.
&&
.UPDATE...A DRIER SOUTHWEST FLOW ALOFT CONTINUES TO ESTABLISH OVER
THE AREA AS A RIDGE OF HIGH PRESSURE OVER DESERT SOUTHWEST WEAKENS
AND CONTINUES TO MOVE EAST. ALL CONVECTIVE STORMS REMAINED WELL
EAST OF THE AREA WITH ONLY A FEW FLAT CUMULUS CLOUDS OVER THE
HIGHER TERRAIN.
FROM THE LATEST ACARS SOUNDINGS...THE MARINE LAYER IS SLIGHTLY
DEEPER THAN LAST NIGHT...AROUND 1100 FEET THIS EVENING. NAM-WRF
SOLUTIONS ARE ARRIVING THIS EVENING AND MODEL SURFACE GRADIENTS
ARE WELL-INITIALIZED. HOWEVER...THE 950 MB TEMPERATURES ARE ABOUT
TWO DEGREES CELSIUS TOO WARM VERSUS ACARS AND RADIOSONDE
SOUNDINGS. NAM-WRF SOLUTIONS ARE WARMING TEMPERATURES AT 950 MB
INDICATING A POSSIBILITY OF A FEW DEGREES WARMING OVER THE INLAND
AREAS. HOWEVER WITH A OPEN WAVE TROUGH TO THE NORTHWEST...SURFACE
GRADIENTS CHANGING VERY LITTLE...AND A SOUTHWEST FLOW ALOFT IN
PLACE...THERE IS SOME DOUBT IN A WARMING TREND ACTUALLY OCCURRING
ON FRIDAY. AS A RESULT...THE PACKAGE FOR FRIDAY WILL REMAIN
UNCHANGED.
FOR THE REST OF THE WEEKEND...SOUTHWEST FLOW ALOFT AND A
DEVELOPING UPPER-LEVEL TROUGH OVER THE NORTHEASTERN PACIFIC WILL
LIKELY KEEP AN ONSHORE FLOW PATTERN IN PLACE OVER THE AREA
THROUGHOUT THE PERIOD. TEMPERATURES WILL BE NEAR SEASONAL NORMALS
FOR THE WEEKEND WITH A CONTINUED MARINE LAYER PRESENCE AT THE
COASTAL AREAS.
&&
.PREV DISCUSSION... /ISSUED 440 PM PDT THU JUL 2 2009/
LONG TERM...FOR EXTENDED...MODELS ON SAME SYNOPTIC PAGE
INDICATING A VERY BLAND PATTERN FOR THE AREA. AT UPPER LEVELS...
TROUGH WILL BECOME ESTABLISHED OVER THE WEST COAST...WITH
SOUTHWEST FLOW PREVAILING OVER OUR AREA. NEAR THE SURFACE...CAN
ANTICIPATE CONTINUED ONSHORE FLOW WITH A GRADUAL DEEPENING OF THE
MARINE LAYER.
WITH THE ABOVE PATTERN...EXPECT A TYPICAL MARINE LAYER FORECAST
FOR THE AREA...WITH NO CONCERN ABOUT ANY MONSOONAL MOISTURE. AS
FOR TEMPS...EXPECT SLIGHTLY COOLER CONDITIONS WITH MOST AREAS
AT OR A FEW DEGREES BELOW SEASONAL NORMS.
&&
.AVIATION...02/2340Z.
VFR CONDITIONS WILL LIKELY PERSIST AT ALL INLAND TERMINALS. AT
COASTAL TERMINALS...VFR CONDITIONS WITH ISOLATED IFR CEILINGS WILL
OCCUR THROUGH 04Z...THEN LIFR TO IFR CONDITIONS WILL DEVELOP BETWEEN
04Z AND 10Z. WITH A BETTER DEVELOPED MARINE INVERSION...THE COASTAL
TERMINALS WILL LIKELY CLEAR LATER ON FRIDAY. THERE IS SOME CONCERN
THAT SOME SITES MAY NOT SEE CLEARING UNTIL 20Z.
KLAX...VFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST 05Z THIS
EVENING. THERE IS A 80 PERCENT CHANCE OF IFR CEILINGS THROUGH 02Z.
AFTER 05Z...IFR CONDITIONS HAVE A 40 PERCENT CHANCE OF ARRIVING.
HOWEVER...IT IS LIKELY THAT IFR CONDITIONS MAY NOT ONSET UNTIL
AROUND 08Z. KLAX MAY STRUGGLE TO CLEAR ON FRIDAY...WITH A 20 PERCENT
CHANCE THAT CLEARING MAY NOT OCCUR UNTIL THE 19Z TO 21Z TIME FRAME.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD WITH NO
WIND ISSUES.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HALL/SETO
PUBLIC...HALL/THOMPSON
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 030036 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
535 PM MST THU JUL 2 2009
.UPDATE...
UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS66 KMTR 022344
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
223 PM PDT THU JUL 2 2009
.DISCUSSION...AS OF 2:23 PM PDT THURSDAY...MOSTLY CLEAR SKIES ARE
EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGE ACROSS THE CWA THIS
AFTERNOON. THERE ARE HOWEVER NUMEROUS THUNDERSTORMS OCCURRING ALONG
THE SIERRA. AFTERNOON TEMPERATURES ARE RUNNING RIGHT AROUND NORMAL
WITH THE COAST SEEING MID 60S TO LOW 70S AND AREAS INLAND IN THE
MID 70S TO MID 80S.
ACCORDING TO THE FORT ORD PROFILER THE MARINE LAYER IS AT ABOUT 1400
FEET DEEP THIS AFTERNOON. MEANWHILE THE ONSHORE PRESSURE GRADIENT IS
AROUND 2 MB. THESE TWO FACTORS SUPPORT THE RECURRENCE OF STRATUS
OVERNIGHT WITH SOME PATCHY DENSE FOG. STRATUS SHOULD STRETCH INTO
THE EAST BAY AREA AND INTO THE SOUTHERN SALINAS VALLEY BY EARLY
MORNING.
AS FOR THE HOLIDAY WEEKEND BOTH THE 1200 UTC OPERATIONAL GFS AND
ECMWF ADVERTISE A LOW APPROACHING THE PACIFIC NORTHWEST.
PRECIPITATION ASSOCIATED WITH THIS LOW WILL STAY WELL TO THE NORTH OF
THE FORECAST AREA. THE AIRMASS APPEARS TO BE FAIRLY DRY THEREFORE NOT
EXPECTING ANY CONVECTION OVER THE CWA BUT MAY SEE SOME CUMULUS OVER
THE NORTHBAY AND EAST-BAY HILLS. AGAIN THIS WEEKEND APPEARS TO BE
TYPICAL FOR A CENTRAL COAST SUMMER WITH MORNING LOW CLOUDS AND
AFTERNOON SUN. TEMPERATURES WILL BE NEAR NORMAL THIS WEEKEND WITH
AFTERNOON HIGHS IN THE MID TO UPPER 60S ALONG THE COAST AND MID TO
UPPER 80S INLAND WITH SOME LOW 90S POSSIBLE IN THE SOUTHERN SALINAS
VALLEY.
THE UPCOMING WORK WEEK WILL BE COOLER WITH AFTERNOON TEMPERATURES
INLAND ONLY REACHING THE LOW TO MID 70S AND MID TO UPPER 60S ALONG
THE COAST. THIS IS DUE TO AN UNSEASONABLY DEEP TROUGH...WELL
ADVERTISED BY BOTH THE ECMWF AND GFS...SLOWLY PASSING OVER THE WEST
COAST. 500MB HEIGHTS WILL DROP TO 573 DM OVER THE BAY AREA TUESDAY
BRINGING 850 TEMPERATURES TO 13 DEGREES CELSIUS. FURTHER COOLING
IS EXPECTED BY WEDNESDAY WITH THE GFS SHOWING 850 TEMPERATURES OF 12
DEGREES CELSIUS FOR THE BAY AREA.
AT THE MOMENT THIS TROUGH APPEARS TO BE DRY FOR THE AREA. HOWEVER...
THE GFS INDICATES A SIGNIFICANT VORTMAX PASSING OVER NORTHERN
CALIFORNIA WEDNESDAY AFTERNOON ACCOMPANIED BY A 110 KT JET MAX. IF
SOME MOISTURE WORKS ITS WAY INTO THE SYSTEM WE COULD SEE A FEW
ELEVATED THUNDERSTORMS AS A RESULT. THIS EVENT IS STILL A WAYS OFF
AND WITH ONLY MARGINAL MID LEVEL MOISTURE PRESENT IN THE MODEL
SOLUTIONS WE HAVE NOT INTRODUCED THUNDERSTORMS INTO THE FORECAST FOR
THE NORTHBAY AREA. THIS SITUATION WILL BE MONITORED AS WE GET CLOSER
TO NEXT WEEK.
&&
.AVIATION...AS OF 4:30 PM PDT THURSDAY...STRATUS HAS RETREATED
AWAY FROM THE IMMEDIATE COAST. SOUTHWESTERLY FLOW WILL BRING
LOW CEILINGS BACK ONSHORE LATER TONIGHT.
VICINITY OF KSFO...SOUTHWESTERLY FLOW WILL KEEP VFR CONDITIONS
THROUGH THE AIRPORT EVENING RUSH HOUR. LOW CEILINGS WILL SPREAD
OVER THE AIRPORT AFTER MIDNIGHT AND STAY THROUGH 17-18Z WITH BASES
AROUND 1000-1200 FEET.
KSFO BRIDGE APPROACH...STRATUS WILL STAY OUT UNTIL AT LEAST 08Z.
BASES EXPECTED TO BE AROUND 1000-1200 FEET. CLEARING BY 18Z.
MONTEREY BAY TERMINALS...STRATUS WILL RETURN BY 04Z WITH CEILINGS
STARTING OUT AT 1000-1500 FEET BEFORE LOWERING TO 500-1000 FEET A
COUPLE OF HOURS LATER. CLEARING BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 022340 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
440 PM PDT THU JUL 2 2009
...UPDATED AVIATION SECTION...
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE SOUTHWEST UNITED STATES
WILL BRING WARM AND DRY CONDITIONS TO THE SOUTHLAND THIS WEEKEND.
EARLY NEXT WEEK...THE RIDGE WILL WEAKEN AND TEMPERATURES WILL
COOL. THE COASTAL MARINE LAYER WILL GRADUALLY INCREASE IN COVERAGE
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM (TODAY-SUN)...LATEST SATELLITE SHOWS SOME AFTERNOON
CUMULUS BUILDUPS OVER THE MOUNTAINS...WITH SUNNY SKIES ELSEWHERE
ACROSS THE AREA. JUST NOT ENOUGH OOMPH TO PRODUCE ANY SHOWERS
OR THUNDERSTORMS THIS AFTERNOON.
FORECAST-WISE...12Z MODELS ARE ON THE SAME SYNOPTIC PAGE. AT UPPER
LEVELS...THE AREA WILL REMAIN BETWEEN A RIDGE OVER THE DESERT
SOUTHWEST AND A TROUGH OVER THE EASTERN PACIFIC. NEAR THE SURFACE
WEAK TO MODERATE ONSHORE FLOW WILL CONTINUE.
THE ABOVE PATTERN WILL PRODUCE A SOUTHWEST FLOW ALOFT WHICH SHOULD
KEEP THE AREA FREE OF MID-LEVEL MOISTURE AND ANY POTENTIAL SHOWER
OR THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD. HOWEVER...H5 HEIGHTS
ACTUALLY INCREASE A LITTLE BIT THROUGH THE WEEKEND...WHICH WILL
KEEP THE MARINE LAYER VERY SHALLOW...ONLY AFFECTING THE COASTAL
AREAS. TEMP WISE...EXPECT NEARLY PERSISTENT CONDITIONS THROUGH
SATURDAY...THEN SOME SLIGHT COOLING ALL AREAS ON SUNDAY. OVERALL
EXPECT AFTERNOON HIGHS TO REMAIN AROUND SEASONAL NORMS THROUGH
SUNDAY. JUST VERY TYPICAL CONDITIONS FOR THIS TIME OF YEAR.
.LONG TERM (MON-THU)...FOR EXTENDED...MODELS ON SAME SYNOPTIC PAGE
INDICATING A VERY BLAND PATTERN FOR THE AREA. AT UPPER LEVELS...
TROUGH WILL BECOME ESTABLISHED OVER THE WEST COAST...WITH SOUTHWEST
FLOW PREVAILING OVER OUR AREA. NEAR THE SURFACE...CAN ANTICIPATE
CONTINUED ONSHORE FLOW WITH A GRADUAL DEEPENING OF THE MARINE
LAYER.
WITH THE ABOVE PATTERN...EXPECT A TYPICAL MARINE LAYER FORECAST
FOR THE AREA...WITH NO CONCERN ABOUT ANY MONSOONAL MOISTURE. AS
FOR TEMPS...EXPECT SLIGHTLY COOLER CONDITIONS WITH MOST AREAS
AT OR A FEW DEGREES BELOW SEASONAL NORMS.
&&
.AVIATION...02/2340Z.
VFR CONDITIONS WILL LIKELY PERSIST AT ALL INLAND TERMINALS. AT
COASTAL TERMINALS...VFR CONDITIONS WITH ISOLATED IFR CEILINGS WILL
OCCUR THROUGH 04Z...THEN LIFR TO IFR CONDITIONS WILL DEVELOP BETWEEN
04Z AND 10Z. WITH A BETTER DEVELOPED MARINE INVERSION...THE COASTAL
TERMINALS WILL LIKELY CLEAR LATER ON FRIDAY. THERE IS SOME CONCERN
THAT SOME SITES MAY NOT SEE CLEARING UNTIL 20Z.
KLAX...VFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST 05Z THIS
EVENING. THERE IS A 80 PERCENT CHANCE OF IFR CEILINGS THROUGH 02Z.
AFTER 05Z...IFR CONDITIONS HAVE A 40 PERCENT CHANCE OF ARRIVING.
HOWEVER...IT IS LIKELY THAT IFR CONDITIONS MAY NOT ONSET UNTIL
AROUND 08Z. KLAX MAY STRUGGLE TO CLEAR ON FRIDAY...WITH A 20 PERCENT
CHANCE THAT CLEARING MAY NOT OCCUR UNTIL THE 19Z TO 21Z TIME FRAME.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD WITH NO
WIND ISSUES.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...THOMPSON
AVIATION...HALL
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSTO 022230
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
330 PM PDT THU JUL 02 2009
.DISCUSSION...
AFTERNOON TEMPS WITHIN A COUPLE DEGREES OF YESTERDAY ATTM AS UPPER
LOW PRESSURE OFF THE CENTRAL CALIFORNIA COAST CONTINUES TO DRIFT
SLOWLY NE. DEFORMATION ZONE ALIGNED SW-NE ACROSS THE NORTHERN
INTERIOR WITH SHORT WAVE LIFTING ACROSS CENTRAL COAST MOVING NE.
SATELLITE IMAGERY SHOWING MAINLY TCU OVER THE COASTAL MOUNTAINS AND
WESTERN PORTIONS OF SHASTA COUNTY ATTM WITH AN ISOLATED CELL NEAR
FRENCH GULCH DEVELOPING INTO A CB. THERMAL TROUGH OVER THE SIERRA
NEVADA THIS AFTERNOON PROVIDING STRONGER UVM HOWEVER SHORT WAVE
TURNING MID-LEVEL FLOW MORE TO THE SW AND SHUNTING MOISTURE
EASTWARD. STILL LOOKS LIKE AN ISOLATED SHOWER OR THUNDERSTORM
POSSIBLE OVER HIGHER TERRAIN OF THE WESTERN SIERRA THROUGH EARLY
EVENING THEN CLEARING. KSFO-KSAC SURFACE PRESSURE GRADIENT TRENDING
UP AND EXPECT MODERATE TO STRONG DELTA BREEZE AGAIN THIS EVENING.
OFFSHORE UPPER LOW FORECAST TO WEAKEN TO TROUGH AND MOVE ACROSS FAR
NORTHERN INTERIOR FRI/FRI NIGHT. NAM CONTINUES SOME AFTERNOON DEEP
MOIST CONVECTION OVER THE MOUNTAINS NORTH OF A KUKI-KSVE LINE.
STRONGER MID-LEVEL SOUTHWEST FLOW TO THE SOUTH SHOULD KEEP ANY STORM
DEVELOPMENT EAST OF CREST. AMS COOLS SOME SYNOPTICALLY FRIDAY WITH
850 MB TEMPS DROPPING ABOUT 2 TO 3 DEG C TO AROUND 22-23 DEG C. AS A
RESULT...MAX TEMPS FRIDAY FOR THE CENTRAL VALLEY EXPECTED TO BE
MAINLY IN THE 90S.
DRIER SOUTHWESTERLY FLOW OVER NORCAL SATURDAY WITH LITTLE CHANGE IN
TEMPS AS ANOTHER LOW PRESSURE SYSTEM DEEPENS IN THE EASTERN PACIFIC.
COOLING TREND BEGINS SUNDAY AS LOW LIFTS TOWARDS THE PACNW AND
ONSHORE FLOW OVER NORCAL INCREASES. COOLING CONTINUES THROUGH THE
MIDDLE OF NEXT WEEK AS LONG WAVE TROUGH BECOMES ESTABLISHED ALONG
THE WEST COAST AND ADDITIONAL SHORT WAVES MOVE THROUGH.
PCH
.EXTENDED DISCUSSION (MONDAY THRU THURSDAY)...
LONGWAVE TROUGH IN PLACE OVER THE ERN PACIFIC THROUGH THE EXTENDED.
SHORT WAVE TROUGHS WILL PROPAGATE INTO THE PACIFIC NW AND EXTREME
NRN CAL. THE FIRST SHORTWAVE WITH A NEUTRAL TILT WILL IMPACT THE
NRN MTNS TUE. THEREFORE WE HAVE INCREASED THE POPS FOR THE AFTN AND
EVENING AND ADDED A SLIGHT CHANCE OF THUNDERSTORMS. TWO WEAKER
POSITIVELY TILTED TROUGHS WILL PROGRESS THROUGH NRN CAL WED AND THU
BUT ONLY GENERATE SOME ENHANCED CUMULUS OVER THE TERRAIN. THIS
PERSISTENT TROUGHING WILL KEEP DAYTIME TEMPS BELOW NORMAL AND AN
ONSHORE WIND REGIME. NORMAL TEMPS FOR NEXT WEEK ARE 96 TO 98 FOR
RED BLUFF AND REDDING...AND 91 TO 94 FROM SACRAMENTO TO MODESTO.
THE MARINE LAYER STRATUS WILL PERSIST AND TEND TO DEEPEN IN RESPONSE
TO THE UPPER LEVEL TROUGH INSIDE OF 130W. JMC
&&
.AVIATION...
VFR CONDS OVER NORCAL EXCEPT ISOLD MVFR/IFR CONDS IN TSRA OVER
COASTAL MTNS AND NEAR SIERRA CREST THROUGH 04Z. LCL IFR CONDS
POSSIBLE IN STRATUS WEST OF TRAVIS 08-16Z. S-SW FLOW ALF WITH LCL
SWLY SFC WIND G30 KTS THRU DELTA AFT 01Z FRI. JMC
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KREV 022224
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
324 PM PDT THU JUL 2 2009
.SHORT TERM...
CONVECTION HAS BEEN MORE ACTIVE TODAY FROM RENO-TAHOE SEWD ACROSS
DOUGLAS-LYON-MINERAL COUNTIES. STRONGEST CELLS FORMED IN RURAL
PORTIONS OF MINERAL COUNTY SO FAR THIS AFTERNOON. WINDS AT SLIDE
MTN FINALLY SWITCHED TO WEST IN PAST HOUR AS THE BACK EDGE OF
CONVECTION APPEARS TO HAVE PUSHED EAST OF TRUCKEE...WHILE FARTHER
SOUTH IN MONO COUNTY ONLY A FEW CELLS REMAIN EAST OF HWY 395.
GUSTY OUTFLOW WINDS WILL REMAIN A THREAT THRU EARLY EVENING
ESPECIALLY IN W-CNTRL NV NORTH OF HWY 50 WHERE DRIER LOW LEVEL AIR
MASS WILL INCREASE DOWNDRAFT MOMENTUM FROM ANY CELLS MOVING INTO
THIS AREA.
MOST ACTIVITY SHOULD DIMINISH AFTER SUNSET AS THE WEAK SHORTWAVE
TROF RESPONSIBLE FOR THE TSTMS EJECTS TO THE NORTHEAST...ALTHOUGH
SOME INSTBY IS EXPECTED TO PUSH INTO FAR NWRN NV AND SURPRISE VLY
OVERNIGHT AND FRI MORNING SO ISOLD TSTMS WERE MAINTAINED IN THOSE
AREAS.
FOR FRIDAY...REDUCED COVERAGE OF CONVECTION IS EXPECTED ALTHOUGH
STUBBORN WEAK LOW OVER NRN CA WILL KEEP THREAT OF SOME ACTIVITY
OVER FAR NERN CA AND NWRN NV. FARTHER SOUTH TO MINERAL-MONO
COUNTIES...A FEW SHORT LIVED CELLS ARE POSSIBLE...BUT ANYTHING
THAT FORMS WILL BE LESS INTENSE COMPARED TO TODAY. WITH DRIER AND
MORE STABLE AIR MASS ADVANCING INTO THE RENO-TAHOE ZONES AND NO
FORCING MECHANISMS INDICATED BY THE NAM AND GFS GUIDANCE...THE
MENTION OF TSTMS WAS REMOVED FOR THESE AREAS.
FOR THE INDEPENDENCE DAY WEEKEND...DRY AND WARM CONDITIONS ARE
EXPECTED ACROSS THE REGION AS SW FLOW ALOFT PREVAILS WITH LITTLE
OR NO DYNAMIC FORCING. SOME LEFTOVER MID LEVEL MOISTURE WILL LEAD
TO SOME CUMULUS BUILDUPS SAT AFTERNOON MAINLY IN MINERAL-MONO
COUNTIES AND ALSO NEAR THE OREGON BORDER...BUT WARMER AIR ALOFT
SHOULD CAP VERTICAL CLOUD GROWTH. WHILE A BRIEF SHOWER CAN NOT BE
RULED OUT...THIS POTENTIAL IS TOO REMOTE TO INCLUDE IN THE
FORECAST TEXT. WINDS ON SATURDAY THE 4TH SHOULD BE ZEPHYR TYPE
BREEZES WITH GUSTS NEAR 25 MPH...WHICH MAY PERSIST UNTIL ABOUT 10
PM FOR THE RENO-SPARKS-CARSON AREAS BUT SHOULD DIMINISH BY DUSK
AROUND TAHOE. FOR SUNDAY...WIND GUSTS WILL INCREASE TO THE 30-35
MPH RANGE AS WEAK SHORTWAVE MOVING INTO THE NWRN US BRUSHES
ACROSS NERN CA-NWRN NV. MJD
.LONG TERM...MONDAY THROUGH THURSDAY...
THE MAIN CHANGES TO THE LONG TERM GRIDS WERE TO LOWER SKY COVER
(EXCEPT ACROSS THE FAR NORTHERN CWA) AND RELATIVE HUMIDITIES.
A LARGE-SCALE UPPER TROUGH WILL BE HANGING AROUND ALONG THE WEST
COAST OR SLIGHTLY OFFSHORE THROUGH THE EXTENDED...WITH AN IMPULSE
EJECTING AROUND THE MAIN TROUGH LATE TUESDAY (GFS) OR WEDNESDAY
(ECMWF). THE IMPULSE WOULD AT MOST BRING A FEW SHOWERS TO THE FAR
NORTH...WITH VERY DRY SOUTHWEST FLOW ELSEWHERE TO WARD OFF
PRECIPITATION. THE MAIN STORY WILL BE THE COOLING TREND...WITH 70S
TO MID 80S IN THE VALLEYS TUESDAY THROUGH THURSDAY (5-10 DEGREES
BELOW AVERAGE). IT WILL ALSO TEND TO BE BREEZY WITH THE PERSISTENT
GRADIENT BETWEEN THE UPPER TROUGH AND A RIDGE OVER THE DESERT
SOUTHWEST. SNYDER
&&
.AVIATION...
LIGHTER WINDS ALOFT THAN EXPECTED AND AN INCOMING DISTURBANCE ARE
ALLOWING SHOWERS AND THUNDERSTORMS TO DEVELOP FURTHER WEST THAN
PREVIOUSLY EXPECTED...WITH A LINE OF CONVECTION IN THE AREA OF
KTVL/KTRK/KRNO TO MOVE EAST OF KRNO (AND AFFECT THE AREA OF KLOL)
CIRCA 01Z. ALL STORMS COULD PRODUCE GUSTY OUTFLOW WINDS...BUT THE
MAIN RISK FOR VERY GUSTY OUTFLOW WINDS WILL BE EAST OF KRNO AND FROM
ABOUT KNFL NORTH...WHERE STRONGER STORMS COULD PRODUCE GUSTS TO
40-45 KTS AND VERY HEAVY RAIN.
FRIDAY...ANY THUNDERSTORMS SHOULD BE RESTRICTED TO NORTH AND EAST OF
A SUSANVILLE TO FALLON TO BRIDGEPORT LINE. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS65 KPSR 022218 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
317 PM MST THU JUL 2 2009
.UPDATE...UPDATED AVIATION DISCUSSIONS.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EARLY AFTERNOON HEATING RESULTED IN A CLUSTER OF STRONG TSTMS IN
VICINITY OF KGBN AND SOUTHWARD INTO PIMA COUNTY. TSTMS FIRED AND
DISSIPATED RATHER QUICKLY...AND ADDITIONAL CONVECTION EARLY THIS
EVENING IS POSSIBLE ALTHO SFC DEW POINTS HOLDING STEADY IN THE UPPER
50S. WILL EXPECT AT LEAST ONE OUTFLOW BOUNDARY TO IMPACT KPHX AND
KIWA FOR 2-4 MILES VSBYS. AN INCREASING CHANCE OF STORMS IS STILL
POSSIBLE AFTER DARK...THROUGH ABOUT 06Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WITH WIND GUSTS TO 40 KTS NEAR KBLH TIL 23Z BUT
STORMS WILL LIKELY DISSIPATE QUICKLY AFTER DARK. WINDS NOT EXPECTED
TO BE SIGNIFICANT TONIGHT INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS66 KEKA 022156
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
300 PM PDT THU JUL 2 2009
.SYNOPSIS...A WEAK AREA OF LOW PRESSURE JUST OFF THE NORTHERN
CALIFORNIA COAST WILL MOVE ACROSS THE REGION FRIDAY AND FRIDAY
NIGHT...MAINTAINING THE THREAT OF ISOLATED THUNDERSTORMS ACROSS
TRINITY COUNTY. OTHERWISE...INLAND AREAS WILL UNDERGO A COOLING
TREND BEGINNING LATE IN THE WEEKEND AND INTO NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY...THE MAIN FORECAST CHALLENGE
IS CONVECTION THIS EVENING AND AGAIN FRIDAY AFTERNOON/EVENING.
VAPOR PIX INDICATE A WEAK LOW JUST SW OF CAPE MENDOCINO AT EARLY
AFTERNOON. NO THUNDERSTORM ACTIVITY HAS OCCURRED AS OF YET...BUT
WILL RETAIN ISOLATED/SCATTERED CHANCES ACROSS EASTERN ZONES FOR THIS
EVENING. ANYTHING THAT FORMS WILL DIMINISH NOT LONG AFTER IT FORMS
AS THE SITUATION IS PURELY DIURNALLY DRIVEN. MEANWHILE ALONG THE
COAST...A STRONG INVERSION IS PRESENT AND WILL KEEP THE COAST LOCKED
IN WITH CLOUDS/FOG AND PROBABLY A LITTLE DRIZZLE OVERNIGHT.
THE AFOREMENTIONED LOW WILL SLOWLY MOVE NE TO THE COAST TOMORROW.
THUNDERSTORM DEVELOPMENT IS AGAIN PROBABLE ACROSS TRINITY
COUNTY BUT THE CONVECTIVE SIGNATURES ARE NOT QUITE AS STRONG AS
THOSE FROM TODAY...SO COVERAGE WILL PROBABLY BE A LITTLE MORE
LIMITED. BY SATURDAY THE LOW WILL FILL AND SHIFT INLAND EFFECTIVELY
ENDING THE THREAT FOR ORGANIZED CONVECTION...ALTHOUGH WE WILL RETAIN
<=10 POPS FOR THE TRINITY COUNTY MOUNTAINS AS SOME WEAKNESS IN THE
UPSTAIRS PATTERN PERSISTS. IN OUR BEST ESTIMATION...THE EVENING
FESTIVITIES OF THE 4TH OF JULY WOULD APPEAR TO FEATURE A LOW
OVERCAST HERE AT THE COAST...BUT INLAND LOCALES WILL EXPERIENCE
PLEASANT AND CLEAR WEATHER. SOME RELIEF FROM THE HOT TEMPERATURES AS
OF LATE FOR INLAND AREAS IS IN STORE...AND THIS COOLING TREND WILL
COMMENCE ON SUNDAY. BURGER
.LONG TERM...SUNDAY THROUGH THURSDAY...MODELS AGREE ON AN UPPER
LEVEL LOW OVER THE PACNW WITH A BROAD TROUGH STRETCHING OFF THE
CENTRAL CALIFORNIA COAST. THIS TROUGH WILL BRING MUCH COOLER TEMPS
TO INLAND LOCATIONS WITH THE POSSIBILITY OF CONVECTION OVER THE
HIGHER TERRAIN TUE AND WED. FOR NOW...WITH UNCERTAINTY IN TIMING OF
THIS TROUGH...WE WILL LEAVE OUT ANY T-STORM MENTION AFTER
COORDINATION WITH NEIGHBORING OFFICES. THIS TROUGH MOVES VERY LITTLE
SO THE WX PATTERN WILL BE STAGNANT FOR MUCH OF THE WEEK. JCA
&&
.AVIATION...LIKE YESTERDAY...THE MARINE STRATUS ENGULFS THE ENTIRE
NORTH COAST. VSBYS HAVE BECOME VFR...BUT CIGS WILL REMAIN IFR. A FEW
BREAKS MAY BE SEEN LATER THIS AFTERNOON AS THE STRATUS LAYER WAFFLES
SLIGHTLY. LIFR CONDITIONS WILL RETURN AFTER SUNSET. VFR
INLAND...WITH SCATTERED THUNDERSTORMS OVER THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. JCA
&&
.MARINE...THE PRESSURE GRADIENT ALONG THE COAST HAS WEAKENED AND LOW
PRESSURE IN THE AREA WILL KEEP IT THAT WAY THROUGH THE END OF THE
FCST PD. SEAS HAVE LAID DOWN AND WINDS WILL REMAIN LIGHT THROUGH THE
WEEKEND. A LONG PD S SWELL AND SHORT PD NW SWELL WILL DOMINATE
DURING THIS TIME. CLARK
&&
.FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS REMAIN POSSIBLE
INTO THE EVENING HOURS ACROSS THE SHASTA-TRINITY...MENDOCINO...AND
SIX RIVERS NF. LIGHTNING STRIKES WILL BE CAPABLE OF INDUCING
ADDITIONAL WILDFIRE STARTS AS WETTING RAINS (EXCEPT DIRECTLY
UNDERNEATH THUNDERSTORM CORES) ARE NOT LIKELY AND FUELS CONTINUE TO
DRY OUT. THE THREAT FOR THUNDERSTORMS WILL BE BACK TOMORROW
AFTERNOON AND EVENING ALTHOUGH THEIR EXTENT AND MAGNITUDE WILL NOT
WARRANT ANY FIRE WEATHER HEADLINES. BURGER
&&
.EKA WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KMTR 022123
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
223 PM PDT THU JUL 2 2009
.DISCUSSION...AS OF 2:23 PM PDT THURSDAY...MOSTLY CLEAR SKIES ARE
EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGE ACROSS THE CWA THIS
AFTERNOON. THERE ARE HOWEVER NUMEROUS THUNDERSTORMS OCCURRING ALONG
THE SIERRA. AFTERNOON TEMPERATURES ARE RUNNING RIGHT AROUND NORMAL
WITH THE COAST SEEING MID 60S TO LOW 70S AND AREAS INLAND IN THE
MID 70S TO MID 80S.
ACCORDING TO THE FORT ORD PROFILER THE MARINE LAYER IS AT ABOUT 1400
FEET DEEP THIS AFTERNOON. MEANWHILE THE ONSHORE PRESSURE GRADIENT IS
AROUND 2 MB. THESE TWO FACTORS SUPPORT THE RECURRENCE OF STRATUS
OVERNIGHT WITH SOME PATCHY DENSE FOG. STRATUS SHOULD STRETCH INTO
THE EAST BAY AREA AND INTO THE SOUTHERN SALINAS VALLEY BY EARLY
MORNING.
AS FOR THE HOLIDAY WEEKEND BOTH THE 1200 UTC OPERATIONAL GFS AND
ECMWF ADVERTISE A LOW APPROACHING THE PACIFIC NORTHWEST.
PRECIPITATION ASSOCIATED WITH THIS LOW WILL STAY WELL TO THE NORTH OF
THE FORECAST AREA. THE AIRMASS APPEARS TO BE FAIRLY DRY THEREFORE NOT
EXPECTING ANY CONVECTION OVER THE CWA BUT MAY SEE SOME CUMULUS OVER
THE NORTHBAY AND EAST-BAY HILLS. AGAIN THIS WEEKEND APPEARS TO BE
TYPICAL FOR A CENTRAL COAST SUMMER WITH MORNING LOW CLOUDS AND
AFTERNOON SUN. TEMPERATURES WILL BE NEAR NORMAL THIS WEEKEND WITH
AFTERNOON HIGHS IN THE MID TO UPPER 60S ALONG THE COAST AND MID TO
UPPER 80S INLAND WITH SOME LOW 90S POSSIBLE IN THE SOUTHERN SALINAS
VALLEY.
THE UPCOMING WORK WEEK WILL BE COOLER WITH AFTERNOON TEMPERATURES
INLAND ONLY REACHING THE LOW TO MID 70S AND MID TO UPPER 60S ALONG
THE COAST. THIS IS DUE TO AN UNSEASONABLY DEEP TROUGH...WELL
ADVERTISED BY BOTH THE ECMWF AND GFS...SLOWLY PASSING OVER THE WEST
COAST. 500MB HEIGHTS WILL DROP TO 573 DM OVER THE BAY AREA TUESDAY
BRINGING 850 TEMPERATURES TO 13 DEGREES CELSIUS. FURTHER COOLING
IS EXPECTED BY WEDNESDAY WITH THE GFS SHOWING 850 TEMPERATURES OF 12
DEGREES CELSIUS FOR THE BAY AREA.
AT THE MOMENT THIS TROUGH APPEARS TO BE DRY FOR THE AREA. HOWEVER...
THE GFS INDICATES A SIGNIFICANT VORTMAX PASSING OVER NORTHERN
CALIFORNIA WEDNESDAY AFTERNOON ACCOMPANIED BY A 110 KT JET MAX. IF
SOME MOISTURE WORKS ITS WAY INTO THE SYSTEM WE COULD SEE A FEW
ELEVATED THUNDERSTORMS AS A RESULT. THIS EVENT IS STILL A WAYS OFF
AND WITH ONLY MARGINAL MID LEVEL MOISTURE PRESENT IN THE MODEL
SOLUTIONS WE HAVE NOT INTRODUCED THUNDERSTORMS INTO THE FORECAST FOR
THE NORTHBAY AREA. THIS SITUATION WILL BE MONITORED AS WE GET CLOSER
TO NEXT WEEK.
&&
.AVIATION...AS OF 10:55 AM PDT THURSDAY...TYPICAL SUMMER FLOW
PATTERN EXPECTED ACROSS THE SAN FRANCISCO AND MONTEREY BAY AREAS THE
NEXT 36 HOURS AS A WEAK UPPER LEVEL TROUGH REMAINS POSTED OVERHEAD.
AT THE SURFACE A MODERATE ONSHORE FLOW WILL BRING GUSTY WINDS TO
THE FAVORED LOCATIONS. THE 2000 FOOT DEEP MARINE LAYER WILL REMAIN
ALONG THE COAST THROUGH THE DAY THEN SPREAD INLAND SIMILAR TO
YESTERDAY. FOR TOMORROW THE LOW CLOUDS WILL EVAPORATE TO THE COAST
BY LATE MORNING.
VICINITY OF KSFO...STRATUS HAS RETREATED TO THE COAST WITH A
FEW CLOUDS IN THE PASS BASED AROUND 1000 FEET. THE STRATUS WILL
SPREAD INTO THE BAY BY 08Z WITH HIGH IFR/LOW VFR CIGS.
KSFO BRIDGE APPROACH...STRATUS WILL RETURN BY 08Z WITH HIGH IFR/LOW
VFR CIGS.
MONTEREY BAY TERMINALS...STRATUS WILL RETURN BY 04Z WITH HIGH IFR/LOW
VFR CIGS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: EVANS
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KMTR 022123
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
223 PM PDT THU JUL 2 2009
.DISCUSSION...AS OF 2:25 PM PDT THURSDAY...MOSTLY CLEAR SKIES ARE
EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGE ACROSS THE CWA THIS
AFTERNOON. THERE ARE HOWEVER NUMEROUS THUNDERSTORMS OCCURRING ALONG
THE SIERRA. AFTERNOON TEMPERATURES ARE RUNNING RIGHT AROUND NORMAL
WITH THE COAST SEEING MID 60S TO LOW 70S AND AREAS INLAND IN THE
MID 70S TO MID 80S.
ACCORDING TO THE FORT ORD PROFILER THE MARINE LAYER IS AT ABOUT 1400
FEET DEEP THIS AFTERNOON. MEANWHILE THE ONSHORE PRESSURE GRADIENT IS
AROUND 2 MB. THESE TWO FACTORS SUPPORT THE RECURRENCE OF STRATUS
OVERNIGHT WITH SOME PATCHY DENSE FOG. STRATUS SHOULD STRETCH INTO
THE EAST BAY AREA AND INTO THE SOUTHERN SALINAS VALLEY BY EARLY
MORNING.
AS FOR THE HOLIDAY WEEKEND BOTH THE 1200 UTC OPERATIONAL GFS AND
ECMWF ADVERTISE A LOW APPROACHING THE PACIFIC NORTHWEST.
PRECIPITATION ASSOCIATED WITH THIS LOW WILL STAY WELL TO THE NORTH OF
THE FORECAST AREA. THE AIRMASS APPEARS TO BE FAIRLY DRY THEREFORE NOT
EXPECTING ANY CONVECTION OVER THE CWA BUT MAY SEE SOME CUMULUS OVER
THE NORTHBAY AND EAST-BAY HILLS. AGAIN THIS WEEKEND APPEARS TO BE
TYPICAL FOR A CENTRAL COAST SUMMER WITH MORNING LOW CLOUDS AND
AFTERNOON SUN. TEMPERATURES WILL BE NEAR NORMAL THIS WEEKEND WITH
AFTERNOON HIGHS IN THE MID TO UPPER 60S ALONG THE COAST AND MID TO
UPPER 80S INLAND WITH SOME LOW 90S POSSIBLE IN THE SOUTHERN SALINAS
VALLEY.
THE UPCOMING WORK WEEK WILL BE COOLER WITH AFTERNOON TEMPERATURES
INLAND ONLY REACHING THE LOW TO MID 70S AND MID TO UPPER 60S ALONG
THE COAST. THIS IS DUE TO AN UNSEASONABLY DEEP TROUGH...WELL
ADVERTISED BY BOTH THE ECMWF AND GFS...SLOWLY PASSING OVER THE WEST
COAST. 500MB HEIGHTS WILL DROP TO 573 DM OVER THE BAY AREA TUESDAY
BRINGING 850 TEMPERATURES TO 13 DEGREES CELSIUS. FURTHER COOLING
IS EXPECTED BY WEDNESDAY WITH THE GFS SHOWING 850 TEMPERATURES OF 12
DEGREES CELSIUS FOR THE BAY AREA.
AT THE MOMENT THIS TROUGH APPEARS TO BE DRY FOR THE AREA. HOWEVER...
THE GFS INDICATES A SIGNIFICANT VORTMAX PASSING OVER NORTHERN
CALIFORNIA WEDNESDAY AFTERNOON ACCOMPANIED BY A 110 KT JET MAX. IF
SOME MOISTURE WORKS ITS WAY INTO THE SYSTEM WE COULD SEE A FEW
ELEVATED THUNDERSTORMS AS A RESULT. THIS EVENT IS STILL A WAYS OFF
AND WITH ONLY MARGINAL MID LEVEL MOISTURE PRESENT IN THE MODEL
SOLUTIONS WE HAVE NOT INTRODUCED THUNDERSTORMS INTO THE FORECAST FOR
THE NORTHBAY AREA. THIS SITUATION WILL BE MONITORED AS WE GET CLOSER
TO NEXT WEEK.
&&
.AVIATION...AS OF 10:55 AM PDT THURSDAY...TYPICAL SUMMER FLOW
PATTERN EXPECTED ACROSS THE SAN FRANCISCO AND MONTEREY BAY AREAS THE
NEXT 36 HOURS AS A WEAK UPPER LEVEL TROUGH REMAINS POSTED OVERHEAD.
AT THE SURFACE A MODERATE ONSHORE FLOW WILL BRING GUSTY WINDS TO
THE FAVORED LOCATIONS. THE 2000 FOOT DEEP MARINE LAYER WILL REMAIN
ALONG THE COAST THROUGH THE DAY THEN SPREAD INLAND SIMILAR TO
YESTERDAY. FOR TOMORROW THE LOW CLOUDS WILL EVAPORATE TO THE COAST
BY LATE MORNING.
VICINITY OF KSFO...STRATUS HAS RETREATED TO THE COAST WITH A
FEW CLOUDS IN THE PASS BASED AROUND 1000 FEET. THE STRATUS WILL
SPREAD INTO THE BAY BY 08Z WITH HIGH IFR/LOW VFR CIGS.
KSFO BRIDGE APPROACH...STRATUS WILL RETURN BY 08Z WITH HIGH IFR/LOW
VFR CIGS.
MONTEREY BAY TERMINALS...STRATUS WILL RETURN BY 04Z WITH HIGH IFR/LOW
VFR CIGS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: EVANS
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KHNX 022119
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
219 PM PDT THU JUL 2 2009
.DISCUSSION...WEAKNESS IN THE UPPER LEVELS IS SLOWLY BUT SURELY
TURNING THE FLOW TO THE SW. NO PRECIP SEEN ON RADAR YET
TODAY...BUT STILL COULD BE AN ISOLD SHOWER OR TSTM THIS EVE AND
KEPT A SLGT CHANCE OVER THE SIERRA. NAM12...GFS...AND EURO SHOW A
VERY STABLE AIRMASS OVER CENTRAL CA THE NEXT FEW DAYS...AND WILL
KEEP FCST DRY.
HEIGHTS AND H85 TEMPS SHOW A SLIGHT RISE FRI AND/OR SAT DEPENDING
ON MODEL. INCREASED MAX TEMPS A DEGREE OR TWO NEXT 2 DAYS OTHERWISE
NO CHANGES MADE TO PREV FCSTS. IN THE MEDIUM RANGE...AN UPPER LOW
IS FCST TO MOVE INTO THE PAC NW BY THE FIRST OF THE WEEK...THEN
LINGER THERE THRU MUCH OF NEXT WEEK. LOWERING HEIGHTS...AN
INCREASINGLY STRONGER ONSHORE FLOW...AND H85 TEMPS IN THE 15-18
DEG/C RANGE WILL PUSH TEMPS BELOW AVERAGE. SOME RECOVERY IN TEMPS
IS POSSIBLE LATER PART OF THE WEEK AS UPPER RIDGE BUILDS WEST FROM
THE PLAINS/SOUTHERN ROCKIES.
&&
.AVIATION...ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE SIERRA
CREST UNTIL 06Z THIS EVENING. OTHERWISE...VFR CONDITIONS WILL
PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR THROUGH 00Z SATURDAY.
&&
.AIR QUALITY ISSUES...
ON THURSDAY JULY 2 2009... UNHEALTHY IN KERN AND TULARE COUNTIES.
UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO... KINGS... MADERA AND
MERCED COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BINGHAM
AVN/FW...MV
WEATHER.GOV/HANFORD
000
FXUS65 KPSR 022119
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
220 PM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
ONE WEAK IMPULSE HAS MOVED INTO NRN AZ...LEAVING MOSTLY SCT CLOUDS
ABOVE 15 THSD FT ACROSS THE PHOENIX AREA. BUT BY 19Z...TOWERING CU
ACTIVITY WAS UNDERWAY OVER HIGHER TERRAIN OF SOUTHERN AZ AND WILL
LIKELY DEVELOP INTO ISOLATED TSTMS THIS AFTERNOON. WITH A DELAYED
WARMING TREND...CONVECTION IS DELAYED. TSTMS SHOULD FIRE A BIT LATER
THAN USUAL...WITH AN EVENING THREAT...04Z-08Z OF OUTFLOWS IMPACTING
THE SKY HARBOR AREA. EXPECT LIGHT DIURNAL TYPE WINDS THRU FRIDAY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
CLEAR SKIES SHOULD BECOME SCT CUMULUS WITH ONLY ISOLD TSTMS OVER
HIGHER TERRAIN THRU 03Z. SW WINDS ALOFT ABOVE 20 THSD FT WILL KEEP
SKIES MAINLY CLEAR LATE TONIGHT AND INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS66 KLOX 022059
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PDT THU JUL 2 2009
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE SOUTHWEST UNITED STATES
WILL BRING WARM AND DRY CONDITIONS TO THE SOUTHLAND THIS WEEKEND.
EARLY NEXT WEEK...THE RIDGE WILL WEAKEN AND TEMPERATURES WILL
COOL. THE COASTAL MARINE LAYER WILL GRADUALLY INCREASE IN COVERAGE
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM (TODAY-SUN)...LATEST SATELLITE SHOWS SOME AFTERNOON
CUMULUS BUILDUPS OVER THE MOUNTAINS...WITH SUNNY SKIES ELSEWHERE
ACROSS THE AREA. JUST NOT ENOUGH OOMPH TO PRODUCE ANY SHOWERS
OR THUNDERSTORMS THIS AFTERNOON.
FORECAST-WISE...12Z MODELS ARE ON THE SAME SYNOPTIC PAGE. AT UPPER
LEVELS...THE AREA WILL REMAIN BETWEEN A RIDGE OVER THE DESERT
SOUTHWEST AND A TROUGH OVER THE EASTERN PACIFIC. NEAR THE SURFACE
WEAK TO MODERATE ONSHORE FLOW WILL CONTINUE.
THE ABOVE PATTERN WILL PRODUCE A SOUTHWEST FLOW ALOFT WHICH SHOULD
KEEP THE AREA FREE OF MID-LEVEL MOISTURE AND ANY POTENTIAL SHOWER
OR THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD. HOWEVER...H5 HEIGHTS
ACTUALLY INCREASE A LITTLE BIT THROUGH THE WEEKEND...WHICH WILL
KEEP THE MARINE LAYER VERY SHALLOW...ONLY AFFECTING THE COASTAL
AREAS. TEMP WISE...EXPECT NEARLY PERSISTENT CONDITIONS THROUGH
SATURDAY...THEN SOME SLIGHT COOLING ALL AREAS ON SUNDAY. OVERALL
EXPECT AFTERNOON HIGHS TO REMAIN AROUND SEASONAL NORMS THROUGH
SUNDAY. JUST VERY TYPICAL CONDITIONS FOR THIS TIME OF YEAR.
.LONG TERM (MON-THU)...FOR EXTENDED...MODELS ON SAME SYNOPTIC PAGE
INDICATING A VERY BLAND PATTERN FOR THE AREA. AT UPPER LEVELS...
TROUGH WILL BECOME ESTABLISHED OVER THE WEST COAST...WITH SOUTHWEST
FLOW PREVAILING OVER OUR AREA. NEAR THE SURFACE...CAN ANTICIPATE
CONTINUED ONSHORE FLOW WITH A GRADUAL DEEPENING OF THE MARINE
LAYER.
WITH THE ABOVE PATTERN...EXPECT A TYPICAL MARINE LAYER FORECAST
FOR THE AREA...WITH NO CONCERN ABOUT ANY MONSOONAL MOISTURE. AS
FOR TEMPS...EXPECT SLIGHTLY COOLER CONDITIONS WITH MOST AREAS
AT OR A FEW DEGREES BELOW SEASONAL NORMS.
&&
.AVIATION...02/1930Z.
REASONABLY GOOD CONFIDENCE IN THE TAFS AS WRITTEN. IFR CONDITIONS IN
THE LATE EVENING THROUGH THE OVERNIGHT HOURS IN THE COASTAL TAF
LOCATIONS. KLAX AND KSMX MAY BE THE EXCEPTION WITH IFR CONDITIONS
STARTING EARLIER AS THE MARINE CLOUDS ARE HUGGING THE COAST LIKE A
LEECH TO SKIN IN THOSE LOCATIONS.
KLAX...GOOD CONFIDENCE IN VFR CONDITIONS THROUGH EARLY THIS
EVENING...FOLLOWED BY IFR CONDITIONS LATER THIS EVENING THROUGH
FRIDAY MORNING.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH FRIDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...THOMPSON
AVIATION...SWEET
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSGX 022017
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
115 PM PDT THU JUL 2 2009
.SYNOPSIS...FAIR WEATHER WILL CONTINUE WITH ENOUGH MOISTURE ALOFT TO
BRING A SLIGHT CHANCE OF THUNDERSTORMS IN THE MOUNTAINS AND DESERTS
THROUGH FRIDAY. MEANWHILE A SHALLOW MARINE LAYER WILL CONTINUE TO
BRING LOW CLOUDS AND FOG NEAR THE COAST EACH NIGHT AND MORNING.
DRIER AIR WILL MOVE INTO THE REGION AND END THE CHANCE OF
THUNDERSTORMS OVER THE HOLIDAY WEEKEND. HIGH PRESSURE WILL WEAKEN
GRADUALLY NEXT WEEK...WHICH WILL BRING SLIGHTLY COOLER WEATHER AND
MORE EXTENSIVE COASTAL CLOUDS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
VIS SATELLITE IMAGERY AT 20Z SHOWED CU OVER THE MOUNTAINS AND
PATCHES OF STUBBORN MARINE STRATUS CLINGING TO THE COAST...
OTHERWISE CLEAR. TEMPS WERE RUNNING WITHIN A FEW DEGREES OF THOSE
OBSERVED YESTERDAY...AND ONSHORE SURFACE PRESSURE GRADIENTS WERE A
BIT STRONGER TO THE LOWER DESERTS. THE WATER VAPOR LOOP SHOWED
DRYING ACROSS SW SOCAL...WITH THE MAIN AXIS OF MOISTURE DRIFTING
FARTHER TO THE E ACROSS AZ AND NV.
UPPER-LEVEL HIGH PRESSURE CENTERED OVER W TEXAS TODAY IS FORECAST TO
BUILD WESTWARD OVER THE HOLIDAY WEEKEND. THIS WILL INCREASE
HEIGHTS/THICKNESS FOR SOME ADDITIONAL WARMING...ESPECIALLY AWAY FROM
THE IMMEDIATE COAST. ALONG THE COASTAL STRIP...EFFECTS WILL BE
MINIMAL AS THE THERMAL LOW OVER THE LOWER COLORADO RIVER VALLEY
CONTINUES TO GENERATE A MODERATE SEA BREEZE EACH DAY...MAINTAINING A
SHALLOW MARINE LAYER. A STRONG/STRENGTHENING INVERSION WILL KEEP
SOME LOW CLOUDS/FOG AT THE BEACHES...EXTENDING LOCALLY INLAND...AT
TIMES THROUGHOUT THE DAY. MARGINAL MOISTURE AND INSTABILITY WILL
CONTINUE A THREAT FOR SCATTERED SHOWERS/TSTORMS AGAIN FRI
AFTERNOON/EVENING IN THE MOUNTAINS AND DESERTS...AND POSSIBLY SAT AS
WELL...BEFORE ALL VESTIGES OF MONSOON MOISTURE RETREAT TO THE EAST.
IT LOOKS LIKE THIS WILL HAPPEN EITHER LATE ON SAT OR SUN...LEAVING
US WITH DRY...SEASONAL JULY WEATHER FOR THE HOLIDAY WEEKEND.
500 MB HEIGHTS GRADUALLY DECREASE EARLY NEXT WEEK AS WESTERLY FLOW
INCREASES ALOFT WITH FURTHER DRYING. THIS WILL CONTINUE OUR NIGHT
AND MORNING LOW CLOUD/FOG PATTERN W OF THE MOUNTAINS...AND CLEAR
SKIES OVER THE FOOTHILLS...MOUNTAINS...AND DESERTS. IT WILL BE
SLIGHTLY COOLER ALL AREAS AS WELL...BUT SEASONAL MUCH OF NEXT WEEK.
LOOKING AHEAD...BOTH THE GFS AND THE ECMWF SLOWLY REBUILD HEIGHTS/
THICKNESS OVER SW CA LATE NEXT WEEK THROUGH THE FOLLOWING WEEKEND.
HOWEVER...THE UPPER HIGH CENTER REMAINS WELL TO THE EAST...OVER THE
MIDDLE OF THE COUNTRY. THIS WOULD FAVOR DRY AND SEASONAL CONDITIONS
FOR JULY WITH WARM TO HOT...SUNNY DAYS INLAND...AND MILD CONDITIONS
UNDER A SHALLOW MARINE LAYER ALONG THE COAST.
&&
.AVIATION...
021900Z...MARINE LAYER BELOW FL018...BROKEN-SCATTERED STRATUS WITH
BASES FL010 AND TOPS FL018 OVER WATER TO 5SM INLAND. BETWEEN
0600-1600 UTC STRATUS LAYER BECOMING OVERCAST AND EXTENDING 15SM
INLAND. OVER MOUNTAINS AND DESERTS SCATTERED-BROKEN CLOUDS BETWEEN
FL100-FL160 TO CONTINUE FOR ANOTHER 24 HOURS. AIR MASS UNSTABLE
ENOUGH UNTIL 0300 UTC TO SUPPORT THUNDERSTORMS WITH TOPS TO FL430.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...JAD
AVIATION...BALFOUR
000
FXUS66 KLOX 021935
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1230 PM PDT THU JUL 2 2009
NEW AVIATION DISCUSSION
.SYNOPSIS...
UPPER RIDGE WILL REMAIN OVER THE DESERT SOUTHWEST THIS WEEKEND...
BRINGING WARM AND DRY CONDITIONS TO THE AREA. THROUGH THE WEEKEND
THE MARINE LAYER WILL REMAIN CONFINED TO COASTAL AREAS. AN UPPER
LOW IS EXPECTED TO MOVE SOUTHEAST DOWN THE WEST COAST STARTING
MONDAY FOR COOLER TEMPERATURES.
&&
.SHORT TERM (TODAY-SAT)...OVERALL...EXPECTING A QUIET DAY ACROSS
THE AREA. LATEST SOUNDINGS INDICATE MARINE INVERSION BETWEEN 1000
AND 1500 FEET. CURRENTLY...STRATUS IS CONFINED TO THE COASTAL
ZONES AND SHOULD BURN OFF RATHER QUICKLY. AS FOR THE CONVECTIVE
THREAT...THINGS ARE NOT LOOKING GOOD. SATELLITE SHOWS THAT THE
UPPER LEVEL FLOW IS BEGINNING TO TURN SOUTHWESTERLY WHILE THE
LATEST MODELS INDICATE VERY UNIMPRESSIVE CONVECTIVE PARAMETERS. SO
WOULD NOT BE SURPRISED TO SEE SOME AFTERNOON CUMULUS CLOUDS...BUT
WILL NOT ANTICIPATE ANY SHOWERS OR THUNDERSTORMS.
UPDATED THE FORECAST EARLIER TO REMOVE POPS FROM THE MOUNTAINS
AND ANTELOPE VALLEY. ALSO...BUMPED UP TEMPS IN THE VENTURA AND
LOS ANGELES VALLEYS AS 24 HOUR TRENDS ARE SEVERAL DEGREES WARMER
AND LOCAL TEMP STUDY DATABASE SHOWS WARMER BOUNDARY LAYER TODAY
WITH WEAKER ONSHORE GRADIENTS.
*** LONG TERM FROM PREVIOUS DISCUSSION ***
.LONG TERM (SUN-WED)...
BOTH GFS AND EC NOW AGREE THAT THE TROF THAT WAS SUPPOSED TO AFFECT
THE STATE OVER THE WEEKEND WILL HOLD OFF UNTIL AT LEAST TUESDAY.
THIS KEEPS THE PATTERN FAIRLY STATIC THROUGH MONDAY AND BOTH SUNDAY
AND MONDAY WILL BE VERY SIMILAR TO JULY FOURTH WITH MORNING LOW
CLOUDS OVER THE COASTS AND SOME OF THE VLYS MAX TEMPS WILL BE CLOSE
TO NORMALS PROBABLY A DEGREE OR TWO BELOW NORMAL ALONG THE COAST.
THE TROF IS FORECAST TO MOVE CLOSER AND SHARPEN SOMEWHAT TUESDAY OR
WEDNESDAY. THIS WILL INCREASE THE MARINE LAYER INTO THE VLYS. LOWER
HGTS WILL ALSO ALLOW THE INTERIOR TO COOL SOME.
&&
.AVIATION...02/1930Z.
REASONABLY GOOD CONFIDENCE IN THE TAFS AS WRITTEN. IFR CONDITIONS IN
THE LATE EVENING THROUGH THE OVERNIGHT HOURS IN THE COASTAL TAF
LOCATIONS. KLAX AND KSMX MAY BE THE EXCEPTION WITH IFR CONDITIONS
STARTING EARLIER AS THE MARINE CLOUDS ARE HUGGING THE COAST LIKE A
LEECH TO SKIN IN THOSE LOCATIONS.
KLAX...GOOD CONFIDENCE IN VFR CONDITIONS THROUGH EARLY THIS
EVENING...FOLLOWED BY IFR CONDITIONS LATER THIS EVENING THROUGH
FRIDAY MORNING.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH FRIDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...THOMPSON
AVIATION...SWEET
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 021913 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1211 PM MST THU JUL 2 2009
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LIGHT PRECIPITATION CONTINUES TO DRIFT NORTHWARD THROUGH
SOUTH-CENTRAL AZ THIS MORNING. AS WAS THE CASE YESTERDAY...EXTENSIVE
CLOUD COVER WILL DELAY THE ONSET OF CONVECTION THIS AFTERNOON ALONG
THE MOGOLLON RIM. ACROSS THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY
CLEAR WITH DEWPOINTS IN THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST
THE ATMOSPHERE WILL BE UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS
THUNDERSTORMS WITHOUT MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM
YUMA TO GILA BEND AND STRETCHING NORTHWARD INTO THE MOJAVE
DESERT...WHERE A VORT LOBE IS ALREADY PRODUCING MORNING
THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS LOWERED JUST A FEW
PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL NORMALS EACH
DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS PERSIST WELL
INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
ONE WEAK IMPULSE HAS MOVED INTO NRN AZ...LEAVING MOSTLY SCT CLOUDS
ABOVE 15 THSD FT ACROSS THE PHOENIX AREA. BUT BY 19Z...TOWERING CU
ACTIVITY WAS UNDERWAY OVER HIGHER TERRAIN OF SOUTHERN AZ AND WILL
LIKELY DEVELOP INTO ISOLATED TSTMS THIS AFTERNOON. WITH A DELAYED
WARMING TREND...CONVECTION IS DELAYED. TSTMS SHOULD FIRE A BIT LATER
THAN USUAL...WITH AN EVENING THREAT...04Z-08Z OF OUTFLOWS IMPACTING
THE SKY HARBOR AREA. EXPECT LIGHT DIURNAL TYPE WINDS THRU FRIDAY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
CLEAR SKIES SHOULD BECOME SCT CUMULUS WITH ONLY ISOLD TSTMS OVER
HIGHER TERRAIN THRU 03Z. SW WINDS ALOFT ABOVE 20 THSD FT WILL KEEP
SKIES MAINLY CLEAR LATE TONIGHT AND INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS66 KMTR 021758
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1100 AM PDT THU JUL 2 2009
UPDATED AVIATION DISCUSSION
.DISCUSSION...AS OF 9:15 AM PDT THURSDAY...FEELS LIKE SUMMER ON
THE CENTRAL COAST THIS MORNING WITH THE LATEST VISIBLE SATELLITE
IMAGE SHOWING STRATUS UP AND DOWN THE COAST AND WELL INTO THE EAST
BAY AREA. STRATUS HAS ALSO PUSHED DEEP INTO THE SALINAS VALLEY. THE
FORT ORD PROFILER IS INDICATING THAT THE MARINE LAYER HAS DEEPENED
TO 1800 FEET AND THE MARINE LAYER IS AT ABOUT THE SAME DEPTH ON
THE 1200 UTC KOAK SOUNDING. AT THIS DEPTH STRATUS WILL STICK AROUND
THE COAST THROUGH MID MORNING.
ANOTHER INTERESTING FEATURE APPARENT ON THE SATELLITE WATER VAPOR
IMAGE IS AN UPPER-LEVEL LOW SLOWLY MIGRATING TOWARDS THE COAST. THIS
FEATURE IS HELPING TO MAINTAIN THE MARINE LAYER AND WILL KEEP HIGH
TEMPERATURES A LITTLE ON THE COOL SIDE ALONG THE COAST THIS
AFTERNOON. OTHERWISE LOOKS LIKE A TYPICAL SUMMER DAY WITH HIGHS IN
THE MID TO UPPER 60S ALONG THE COAST AND 80S TO LOW 90S INLAND.
AS FOR THE HOLIDAY WEEKEND BOTH THE 0600 UTC OPERATIONAL GFS AND
0000 UTC ECMWF ADVERTISE A LOW APPROACHING THE PACIFIC NORTHWEST.
PRECIPITATION ASSOCIATED WITH THIS LOW WILL STAY WELL TO THE NORTH OF
THE FORECAST AREA. THE AIRMASS APPEARS TO BE FAIRLY DRY THEREFORE NOT
EXPECTING ANY CONVECTION OVER THE CWA BUT MAY SEE SOME CUMULUS OVER
THE NORTHBAY AND EAST-BAY HILLS. AGAIN THIS WEEKEND APPEARS TO BE
TYPICAL FOR A CENTRAL COAST SUMMER WITH MORNING LOW CLOUDS AND
AFTERNOON SUN. TEMPERATURES WILL BE NEAR NORMAL THIS WEEKEND WITH
AFTERNOON HIGHS IN THE MID TO UPPER 60S ALONG THE COAST AND MID TO
UPPER 80S INLAND WITH SOME LOW 90S POSSIBLE IN THE SOUTHERN SALINAS
VALLEY.
THE UPCOMING WORK WEEK WILL BE COOLER WITH AFTERNOON TEMPERATURES
INLAND ONLY REACHING THE LOW TO MID 70S AND MID TO UPPER 60S ALONG
THE COAST. THIS IS DUE TO AN UNSEASONABLY DEEP TROUGH...WELL
ADVERTISED BY BOTH THE ECMWF AND GFS...SLOWLY PASSING OVER THE WEST
COAST. 500MB HEIGHTS WILL DROP TO 573 DM OVER THE BAY AREA TUESDAY
BRINGING 850 TEMPERATURES TO 13 DEGREES CELSIUS. FURTHER COOLING
IS EXPECTED BY WEDNESDAY WITH THE GFS SHOWING 850 TEMPERATURES OF 12
DEGREES CELSIUS FOR THE BAY AREA. THIS TROUGH APPEARS TO BE DRY
FOR THE AREA HOWEVER THIS SITUATION WILL BE MONITORED AS WE GET
CLOSER TO NEXT WEEK.
&&
.AVIATION...AS OF 10:55 AM PDT THURSDAY...TYPICAL SUMMER FLOW
PATTERN EXPECTED ACROSS THE SAN FRANCISCO AND MONTEREY BAY AREAS THE
NEXT 36 HOURS AS A WEAK UPPER LEVEL TROUGH REMAINS POSTED OVERHEAD.
AT THE SURFACE A MODERATE ONSHORE FLOW WILL BRING GUSTY WINDS TO
THE FAVORED LOCATIONS. THE 2000 FOOT DEEP MARINE LAYER WILL REMAIN
ALONG THE COAST THROUGH THE DAY THEN SPREAD INLAND SIMILAR TO
YESTERDAY. FOR TOMORROW THE LOW CLOUDS WILL EVAPORATE TO THE COAST
BY LATE MORNING.
VICINITY OF KSFO...STRATUS HAS RETREATED TO THE COAST WITH A
FEW CLOUDS IN THE PASS BASED AROUND 1000 FEET. THE STRATUS WILL
SPREAD INTO THE BAY BY 08Z WITH HIGH IFR/LOW VFR CIGS.
KSFO BRIDGE APPROACH...STRATUS WILL RETURN BY 08Z WITH HIGH IFR/LOW
VFR CIGS.
MONTEREY BAY TERMINALS...STRATUS WILL RETURN BY 04Z WITH HIGH IFR/LOW
VFR CIGS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: EVANS
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 021635
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
935 AM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LIGHT PRECIPITATION CONTINUES TO DRIFT NORTHWARD THROUGH
SOUTH-CENTRAL AZ THIS MORNING. AS WAS THE CASE YESTERDAY...EXTENSIVE
CLOUD COVER WILL DELAY THE ONSET OF CONVECTION THIS AFTERNOON ALONG
THE MOGOLLON RIM. ACROSS THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY
CLEAR WITH DEWPOINTS IN THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST
THE ATMOSPHERE WILL BE UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS
THUNDERSTORMS WITHOUT MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM
YUMA TO GILA BEND AND STRETCHING NORTHWARD INTO THE MOJAVE
DESERT...WHERE A VORT LOBE IS ALREADY PRODUCING MORNING
THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS LOWERED JUST A FEW
PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL NORMALS EACH
DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS PERSIST WELL
INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
THUNDERSTORM ACTIVITY WILL CONTINUE TO DIMINISH THIS MORNING OVER
THE AREA...SOME ACTIVITY WILL CONTINUE OVER THE OPEN DESERTS WEST OF
LUKE AFB UNTIL SUNRISE...WITH LINGERING DEBRIS CLOUDINESS THE REST
OF THE MORNING. EASTERLY WINDS WILL PERSIST AT KPHX/KIWA THROUGH 18Z
...THEN WINDS BECOME WEST-SOUTHWESTERLY INTO THE AFTERNOON HOURS.
THUNDERSTORM POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT
LOOK SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL
HELP REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP OVER THE HIGHER TERRAIN NORTH AND EAST OF KPHX/KIWA.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
SOME AREAS OF MID AND HIGH CLOUDINESS WILL SLOWLY DISSIPATE THIS
MORNING. ISOLATED STORM DEVELOPMENT WILL BEGIN THURSDAY AFTERNOON
...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...VLM
FIRE WEATHER...VLM
000
FXUS66 KMTR 021616
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
916 AM PDT THU JUL 2 2009
UPDATED AVIATION DISCUSSION
.DISCUSSION...AS OF 9:15 AM PDT THURSDAY...FEELS LIKE SUMMER ON
THE CENTRAL COAST THIS MORNING WITH THE LATEST VISIBLE SATELLITE
IMAGE SHOWING STRATUS UP AND DOWN THE COAST AND WELL INTO THE EAST
BAY AREA. STRATUS HAS ALSO PUSHED DEEP INTO THE SALINAS VALLEY. THE
FORT ORD PROFILER IS INDICATING THAT THE MARINE LAYER HAS DEEPENED
TO 1800 FEET AND THE MARINE LAYER IS AT ABOUT THE SAME DEPTH ON
THE 1200 UTC KOAK SOUNDING. AT THIS DEPTH STRATUS WILL STICK AROUND
THE COAST THROUGH MID MORNING.
ANOTHER INTERESTING FEATURE APPARENT ON THE SATELLITE WATER VAPOR
IMAGE IS AN UPPER-LEVEL LOW SLOWLY MIGRATING TOWARDS THE COAST. THIS
FEATURE IS HELPING TO MAINTAIN THE MARINE LAYER AND WILL KEEP HIGH
TEMPERATURES A LITTLE ON THE COOL SIDE ALONG THE COAST THIS
AFTERNOON. OTHERWISE LOOKS LIKE A TYPICAL SUMMER DAY WITH HIGHS IN
THE MID TO UPPER 60S ALONG THE COAST AND 80S TO LOW 90S INLAND.
AS FOR THE HOLIDAY WEEKEND BOTH THE 0600 UTC OPERATIONAL GFS AND
0000 UTC ECMWF ADVERTISE A LOW APPROACHING THE PACIFIC NORTHWEST.
PRECIPITATION ASSOCIATED WITH THIS LOW WILL STAY WELL TO THE NORTH OF
THE FORECAST AREA. THE AIRMASS APPEARS TO BE FAIRLY DRY THEREFORE NOT
EXPECTING ANY CONVECTION OVER THE CWA BUT MAY SEE SOME CUMULUS OVER
THE NORTHBAY AND EAST-BAY HILLS. AGAIN THIS WEEKEND APPEARS TO BE
TYPICAL FOR A CENTRAL COAST SUMMER WITH MORNING LOW CLOUDS AND
AFTERNOON SUN. TEMPERATURES WILL BE NEAR NORMAL THIS WEEKEND WITH
AFTERNOON HIGHS IN THE MID TO UPPER 60S ALONG THE COAST AND MID TO
UPPER 80S INLAND WITH SOME LOW 90S POSSIBLE IN THE SOUTHERN SALINAS
VALLEY.
THE UPCOMING WORK WEEK WILL BE COOLER WITH AFTERNOON TEMPERATURES
INLAND ONLY REACHING THE LOW TO MID 70S AND MID TO UPPER 60S ALONG
THE COAST. THIS IS DUE TO AN UNSEASONABLY DEEP TROUGH...WELL
ADVERTISED BY BOTH THE ECMWF AND GFS...SLOWLY PASSING OVER THE WEST
COAST. 500MB HEIGHTS WILL DROP TO 573 DM OVER THE BAY AREA TUESDAY
BRINGING 850 TEMPERATURES TO 13 DEGREES CELSIUS. FURTHER COOLING
IS EXPECTED BY WEDNESDAY WITH THE GFS SHOWING 850 TEMPERATURES OF 12
DEGREES CELSIUS FOR THE BAY AREA. THIS TROUGH APPEARS TO BE DRY
FOR THE AREA HOWEVER THIS SITUATION WILL BE MONITORED AS WE GET
CLOSER TO NEXT WEEK.
&&
.AVIATION...AS OF 5:00 AM PDT THURSDAY...WITH WEAK LOW
PRESSURE OFF THE CALIFORNIA COAST LIGHT SOUTHERLY WIND FLOW CONTINUES
OVER THE CENTRAL CALIFORNIA COASTLINE. COMBINED WITH MODERATE
ONSHORE PRESSURE GRADIENTS...THE WEAK COASTAL SOUTHERLY FLOW BRINGS
STRATUS INTO SOUTHERN MRY BAY EARLY AND THEN BRINGS STRATUS INTO
THE SAN FRANCISCO BAY SLIGHTLY DELAYED.
VICINITY OF KSFO...STRATUS IS FILLING INTO THE BAY WITH HIGH IFR/LOW
VFR CIGS. BASES VARY FROM 700-1100 FT MSL AND EXPECTED TO PERSIST
UNTIL 1730Z. HIGH IFR/LOW VFR CIGS ARE AGAIN EXPECTED TO
PUSH BACK INTO THE BAY BY 08Z TONIGHT.
KSFO BRIDGE APPROACH...STRATUS WITH CIGS011-014 OVER THE BAY AND
IMPROVING TO SCT AROUND 1715Z.
MONTEREY BAY TERMINALS...IFR CIGS 6-8 HND FT MSL BURNING BACK TO THE
COAST AROUND 18Z. HIGH IFR CIGS IN STRATUS RETURNING AFT 04Z THIS
EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KHNX 021553
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
853 AM PDT THU JUL 2 2009
.UPDATE...WEAK UPPER LOW OFF THE COAST IS CONTINUING TO BRING A
SOMEWHAT MOIST MID-LEVEL SOUTH FLOW TO THE REGION. THETA-E RIDGE
AND LIFTEDS ARE MARGINAL FOR TSTMS IN THE SIERRA...SO 20 POP
LOOKS GOOD. DOUBTFUL ANYTHING WILL OCCUR TEHACHAPIS AND DESERTS OF
KERN COUNTY AS MID-LEVEL DRYING IS MORE PREVALENT THERE...AT LEAST
ON WATER VAPOR PIX. TEMPS TODAY NEARLY IDENTICAL TO YESTERDAY
BASED ON MORNING FRESNO AIRCRAFT SOUNDING...AND KVBG AND KOAK
SOUNDINGS AT H85. NO CHANGES TO CURRENT FCST NEEDED.
&&
.PREVIOUS DISCUSSION...EDWARDS RADAR SHOWS AN INCREASE IN
THUNDERSTORM ACTIVITY EAST OF THE AREA OVER SAN BERNARDINO COUNTY
EARLY THIS MORNING AS THE STEADY NORTHWARD STREAM OF MOISTURE IS
COMING UNDER THE INFLUENCE OF THE INCOMING SHORTWAVE TROUGH NOW
PUSHING TOWARD THE CENTRAL COAST. THE BIG QUESTION FOR TODAY OVER
THE HANFORD FORECAST AREA IS HOW FAR WEST AND EXTENSIVE THE
THUNDERSTORM THREAT WILL BE. THE WEATHER SCENARIO APPEARS TO BE
THE CLASSIC BATTLE BETWEEN INCREASING MORE STABLE SOUTHWEST FLOW
VERSUS LINGERING MOISTURE AND INCREASED DYNAMICS. WATER VAPOR
IMAGERY IS ALREADY SHOWING INCREASED LIFT OVER CENTRAL CALIFORNIA
AS THE TROUGH APPROACHES HOWEVER IT APPEARS THE DEEPER MOISTURE IS
LOCATED TO THE EAST OF THE AREA AND WILL LIKELY STAY THAT WAY.
THERE MAY BE A BRIEF PERIOD OF THE MID LEVEL FLOW BACKING TO THE
SOUTH AND POSSIBLY THE SOUTHEAST THIS AFTERNOON AND THIS WOULD
ALLOW FOR THE BEST SHOT AT THUNDERSTORM DEVELOPMENT IN THE SIERRA
AND THE KERN COUNTY MOUNTAINS AND DESERTS. WILL LEAVE THE CURRENT
POPS ALONE AS THEY ARE IN THE SLIGHT CHANCE TO CHANCE CATEGORY. BY
LATER TONIGHT AS THE SHORT WAVE MOVES ONSHORE AND TO THE EAST,
NEARLY ALL OF THE MOISTURE WILL BE SHIFTED TO THE EAST EFFECTIVELY
ENDING ANY THUNDERSTORM THREAT. A DRY SOUTHWEST FLOW IS THEN
PROJECTED TO CONTINUE WELL INTO NEXT WEEK, THUS THE THUNDER THREAT
IS A ONE SHOT DEAL TODAY.
AS FOR TEMPERATURES, LITTLE CHANGE SHOULD OCCUR THROUGH SATURDAY
WITH SOME MINOR COOLING SUNDAY AS HEIGHTS BEGIN TO FALL. BY MONDAY
AND ESPECIALLY TUESDAY FORECAST MODELS BRING IN MUCH LOWER HEIGHTS
AS A LOW PRESSURE CENTER IS PROGGED TO MOVE ACROSS NORTHERN
CALIFORNIA. THE COMBINATION OF LOWER HEIGHTS AND MARINE AIR WILL
CERTAINLY BRING A NOTABLE COOL DOWN WITH LOTS OF 80S OVER THE SAN
JOAQUIN VALLEY AND EVEN INTO THE KERN COUNTY DESERTS.
&&
.AVIATION...ISOLATED THUNDERSTORMS CAN BE EXPECTED OVER THE
SOUTHERN SIERRA NEVADA AND THE KERN COUNTY MOUNTAINS AND DESERT
BETWEEN 19Z TODAY AND 04Z FRIDAY. OTHERWISE...VFR CONDITIONS
WILL PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR THROUGH 18Z
FRIDAY.
&&
.AIR QUALITY ISSUES...
ON THURSDAY JULY 2 2009... UNHEALTHY IN KERN AND TULARE COUNTIES.
UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO... KINGS... MADERA AND
MERCED COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...BINGHAM/DUDLEY
AVN/FW...MV
WEATHER.GOV/HANFORD
000
FXUS66 KSTO 021545
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
845 AM PDT THU JUL 02 2009
.DISCUSSION...
UPPER LOW PRESSURE OFF THE CENTRAL CALIFORNIA COAST IS CONTINUING TO
DRIFT SLOWLY NE AS HIGH PRESSURE CONTINUES OVER THE 4 CORNERS.
DEFORMATION ZONE ALIGNED SW-NE ACROSS THE NORTHERN INTERIOR WITH
SHORT WAVE BEGINNING TO CROSS THE CENTRAL COAST MOVING NE. THIS
FEATURE NOT MODELED WELL BUT WILL HELP TO PROVIDE LIFT OVER THE
MOUNTAINS THIS AFTERNOON. KRNO MORNING SOUNDING SHOWING WEAKER CAP
AND MID-LEVEL INSTABILITY AND MOISTURE IN PLACE AS A LOOK OUT THE
WINDOW REVEALS ACCAS OVER THE SIERRA. NAM KBLU BUFKIT PROFILE
SHOWING CAPES INCREASING TO OVER 1700 J/KG THIS AFTERNOON WITH
NCAPES AT 0.23. THUS POTENTIAL FOR THUNDERSTORMS OVER THE WESTERN
SIERRA NEVADA LOOKS BETTER TODAY THAN WEDNESDAY HOWEVER MID-LEVEL
FLOW BECOMES A LITTLE MORE SWLY THIS AFTERNOON SUGGESTING STORMS
WILL BE CONFINED TO HIGHER TERRAIN. INSTABILITY AND LIFT WILL ALSO
INCREASE OVER THE COASTAL MOUNTAINS AND PORTIONS OF THE NORTHERN
INTERIOR THIS AFTERNOON WITH APPROACHING SHORT WAVE AND OFFSHORE
UPPER LOW. PWS MODELED OVER AN INCH THIS AFTERNOON ALONG THE COASTAL
RANGE SUGGESTING BETTER POTENTIAL FOR WETTING STORMS IN THIS AREA.
DEPTH OF MARINE LAYER HAS REMAINED STEADY OVERNIGHT AT AROUND 1800
FEET. FOG PRODUCT SHOWING SOME STRATUS INTO SUISUN BAY THIS MORNING
BUT THAT`S EXTENT OF EASTWARD PROGRESSION. KSFO-KSAC SURFACE
PRESSURE GRADIENT AROUND 2.5 MB AND DECREASING WHICH WILL BE THE
TREND THROUGH LATE MORNING INTO EARLY AFTERNOON. MAX TEMPS TODAY
EXPECTED TO BE NEAR TO SLIGHTLY WARMER OVER THE NORTHERN INTERIOR
AND SLIGHTLY COOLER NEAR THE DELTA AND SOUTHERN SAC VALLEY.
OFFSHORE UPPER LOW FORECAST TO WEAKEN TO TROUGH AND MOVE ACROSS FAR
NORTHERN INTERIOR FRI/FRI NIGHT. NAM CONTINUES SOME AFTERNOON DEEP
MOIST CONVECTION OVER THE MOUNTAINS NORTH OF A KUKI-KSVE LINE.
STRONGER MID-LEVEL SOUTHWEST FLOW TO THE SOUTH SHOULD KEEP ANY STORM
DEVELOPMENT CREST EASTWARD. AMS COOLS SOME SYNOPTICALLY FRIDAY WITH
850 MB TEMPS DROPPING ABOUT 2 TO 3 DEG C TO AROUND 22-23 DEG C. AS A
RESULT...MAX TEMPS FRIDAY FOR THE CENTRAL VALLEY EXPECTED TO BE
MAINLY IN THE 90S.
DRIER SOUTHWESTERLY FLOW OVER NORCAL SATURDAY WITH LITTLE CHANGE IN
TEMPS AS ANOTHER LOW PRESSURE SYSTEM DEEPENS IN THE EASTERN PACIFIC.
COOLING TREND BEGINS SUNDAY AS LOW LIFTS TOWARDS THE PACNW AND
ONSHORE FLOW OVER NORCAL INCREASES. COOLING CONTINUES THROUGH THE
MIDDLE OF NEXT WEEK AS LONG WAVE TROUGH BECOMES ESTABLISHED ALONG
THE WEST COAST AND ADDITIONAL SHORT WAVES MOVE THROUGH. VALLEY TEMPS
EXPECTED IN THE 80S MONDAY INTO WEDNESDAY. GFS/ECMWF SUGGEST SOME
PRECIP POSSIBLE OVER THE FAR NORTHERN INTERIOR WEDNESDAY. IN
ADDITION...THERE WILL BE PERIODS OF GUSTY SOUTHWEST WIND THROUGH
DELTA AND OVER HIGHER TERRAIN AS SHORT WAVES MOVE THROUGH.
PCH
&&
.AVIATION...
UPR LOW IN EPAC WL SLOLY MOV NE TWDS NORCAL CST NXT 24-36 HRS AS 4
CRNRS HIGH CONTS. VFR CONDS OVR INTR NORCAL EXC ISOLD MVFR/IFR CONDS
POSS IN TSRA OMTNS BTWN 21Z-04Z AND LCL IFR CONDS POSS IN ST VCNTY
DELTA TIL 18Z. GENLY S-SW FLOW ALF WITH LCL SWLY SFC WND GSTS TO 30
KTS THRU DELTA AFT 01Z FRI.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KLOX 021543
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
843 AM PDT THU JUL 2 2009
.SYNOPSIS...
UPPER RIDGE WILL REMAIN OVER THE DESERT SOUTHWEST THIS WEEKEND...
BRINGING WARM AND DRY CONDITIONS TO THE AREA. THROUGH THE WEEKEND
THE MARINE LAYER WILL REMAIN CONFINED TO COASTAL AREAS. AN UPPER
LOW IS EXPECTED TO MOVE SOUTHEAST DOWN THE WEST COAST STARTING
MONDAY FOR COOLER TEMPERATURES.
&&
.SHORT TERM (TODAY-SAT)...OVERALL...EXPECTING A QUIET DAY ACROSS
THE AREA. LATEST SOUNDINGS INDICATE MARINE INVERSION BETWEEN 1000
AND 1500 FEET. CURRENTLY...STRATUS IS CONFINED TO THE COASTAL
ZONES AND SHOULD BURN OFF RATHER QUICKLY. AS FOR THE CONVECTIVE
THREAT...THINGS ARE NOT LOOKING GOOD. SATELLITE SHOWS THAT THE
UPPER LEVEL FLOW IS BEGINNING TO TURN SOUTHWESTERLY WHILE THE
LATEST MODELS INDICATE VERY UNIMPRESSIVE CONVECTIVE PARAMETERS. SO
WOULD NOT BE SURPRISED TO SEE SOME AFTERNOON CUMULUS CLOUDS...BUT
WILL NOT ANTICIPATE ANY SHOWERS OR THUNDERSTORMS.
UPDATED THE FORECAST EARLIER TO REMOVE POPS FROM THE MOUNTAINS
AND ANTELOPE VALLEY. ALSO...BUMPED UP TEMPS IN THE VENTURA AND
LOS ANGELES VALLEYS AS 24 HOUR TRENDS ARE SEVERAL DEGREES WARMER
AND LOCAL TEMP STUDY DATABASE SHOWS WARMER BOUNDARY LAYER TODAY
WITH WEAKER ONSHORE GRADIENTS.
*** LONG TERM FROM PREVIOUS DISCUSSION ***
.LONG TERM (SUN-WED)...
BOTH GFS AND EC NOW AGREE THAT THE TROF THAT WAS SUPPOSED TO AFFECT
THE STATE OVER THE WEEKEND WILL HOLD OFF UNTIL AT LEAST TUESDAY.
THIS KEEPS THE PATTERN FAIRLY STATIC THROUGH MONDAY AND BOTH SUNDAY
AND MONDAY WILL BE VERY SIMILAR TO JULY FOURTH WITH MORNING LOW
CLOUDS OVER THE COASTS AND SOME OF THE VLYS MAX TEMPS WILL BE CLOSE
TO NORMALS PROBABLY A DEGREE OR TWO BELOW NORMAL ALONG THE COAST.
THE TROF IS FORECAST TO MOVE CLOSER AND SHARPEN SOMEWHAT TUESDAY OR
WEDNESDAY. THIS WILL INCREASE THE MARINE LAYER INTO THE VLYS. LOWER
HGTS WILL ALSO ALLOW THE INTERIOR TO COOL SOME.
&&
.AVIATION...02/1200Z.
PATCHY MARINE LAYER SHOULD COVER ALL COASTAL SITES LATER WITHIN A
COUPLE HOURS...THEN LIKELY CLEAR BETWEEN 16Z AND 18Z. THERE IS A
SLIGHT CHANCE OF TSTMS AROUND KPMD AND KWJF BETWEEN 21Z AND 04Z THIS
AFTERNOON. EXPECT ANOTHER PATCHY MARINE LAYER TONIGHT...WITH VERY
LITTLE CONFIDENCE IN ARRIVAL TIMES. AT THE LEAST...CIGS SHOULD HOLD
OFF UNTIL AFTER 06Z.
KLAX...MODERATE CONFIDENCE IN CURRENT TAF. HIGH CONFIDENCE IN
BURNOFF WITHIN AN HOUR OF FORECAST. LESS CONFIDENCE IN ARRIVAL TIMES
TONIGHT...BUT SHOULD BE IN IFR RANGE.
KBUR...VERY GOOD CONFIDENCE IN TAF...WITH VFR SKIES THROUGH THE
PERIOD.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...THOMPSON
AVIATION...SWEET
SYNOPSIS...HOFFER
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KSGX 021542
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
842 AM PDT THU JUL 2 2009
.SYNOPSIS...FAIR WEATHER WILL CONTINUE WITH ENOUGH MOISTURE ALOFT TO
BRING A SLIGHT CHANCE OF THUNDERSTORMS IN THE MOUNTAINS AND DESERTS
THROUGH FRIDAY. MEANWHILE A SHALLOW MARINE LAYER WILL CONTINUE TO
BRING LOW CLOUDS AND FOG NEAR THE COAST EACH NIGHT AND MORNING.
DRIER AIR WILL MOVE INTO THE REGION AND END THE CHANCE OF
THUNDERSTORMS OVER THE HOLIDAY WEEKEND. HIGH PRESSURE WILL WEAKEN
GRADUALLY NEXT WEEK...WHICH WILL BRING SLIGHTLY COOLER WEATHER AND
MORE EXTENSIVE COASTAL CLOUDS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
VIS SATELLITE IMAGERY SHOWS THE A SOLID MARINE LAYER WELL INTO THE
SAN DIEGO COUNTY VALLEYS...WHILE ONLY PATCHY IN ORANGE COUNTY AT
15Z. ELSEWHERE MID/HIGH CLOUDS COVERED THE NORTHERN DESERT AREAS OF
SAN DIEGO AND MUCH OF THE COACHELLA VALLEY. ALL CONVECTION WAS WELL
TO THE NE TOWARD LAS VEGAS. 3-5MB ONSHORE SURFACE PRESSURE GRADIENTS
CONTINUED FROM KSAN TO THE DESERTS. THE 12Z MIRAMAR SOUNDING HAD A
STRONG 10 DEGREE C INVERSION BASED NEAR 1600 FT WITH WEAK FLOW BELOW
20K FT.
A STRONG UPPER-LEVEL HIGH WAS OVER W TEXAS THIS MORNING WITH DEEP
MOISTURE ADVECTION EXTENDING NORTHWARD FROM MEXICO INTO AZ. A WEAK
UPPER-LEVEL TROUGH WAS EVIDENT IN WATER VAPOR IMAGERY AND EXTENDED
FROM OFF THE CENTRAL COAST...TO JUST S OF THE CHANNEL ISLANDS.
MODELS INDICATE THE HIGH WILL HOLD/BUILD OVER THE AREA TODAY...WITH
LITTLE IF ANY SYNOPTIC SCALE FORCING HERE FROM THE TROUGH TO THE NW.
THAT LEAVES US WITH AIRMASS CONSIDERATIONS FOR THUNDERSTORM
POTENTIAL. NO YUMA SOUNDING WAS AVBL AT 15Z. SO BASED ON THE MIRAMAR
SOUNDING... INSTABILITY AND MOISTURE WERE MARGINAL BUT WINDS WERE
WEAK...AND BASED ON THE SATELLITE/MODEL GRADIENT OF MOISTURE TOWARD
THE DESERTS...OUR MOUNTAINS AND DESERTS WILL PROBABLY BE ELIGIBLE
FOR ISOLATED/ SCATTERED SHOWERS/TSTORMS BY THIS AFTERNOON. THE 12Z
NAM SHOWS BETTER INSTABILITY OVER OUR DESERTS AND POINTS EAST...SO
THE CURRENT FORECAST OF SLIGHT CHANCE FOR MEASURABLE PRECIPITATION
IN THE MOUNTAINS AND DESERTS LOOKS GOOD. AT THE COAST...MARINE
CLOUDS SHOULD CLEAR BY MID/LATE MORNING...BUT DUE TO THE STRONG
INVERSION...MAY HOLD AT SOME BEACHES THROUGHOUT THE DAY.
500 MB HEIGHTS BUILD FURTHER INTO FRI WITH LITTLE CHANGE IN THE
MOISTURE PROFILE SO LITTLE CHANGE EXPECTED. BY SAT AND THROUGH THE
WEEKEND...WESTERLY FLOW INCREASES ALOFT WITH FURTHER DRYING.
ISOLATED THUNDERSTORMS ARE STILL POSSIBLE ON SAT...BUT AFTER THAT...
THE ATMOSPHERE DRIES ENOUGH TO REMOVE EVEN A SLIGHT CHANCE. SO FOR
THE REMAINDER OF THE HOLIDAY WEEKEND...MILD AT THE COAST WITH
TYPICAL NIGHT AND MORNING CLOUDS...WITH WARM AND SUNNY DAYS INLAND.
GFS/ECMWF MEDIUM RANGE GUIDANCE KEEPS A LONG-WAVE TROUGH ANCHORED
ALONG THE WEST COAST NEXT WEEK. THIS KEEPS US IN A DRY WESTERLY FLOW
ALOFT FOR NO RAIN AND SEASONAL TEMPS.
&&
.AVIATION...
021430Z...MARINE LAYER BELOW FL018...BROKEN STRATUS WITH BASES
FL007-FL010 AND TOPS BETWEEN FL015-FL018..EXTENDING INLAND ABOUT
25SM FROM CAMP PENDLETON SOUTHWARD AND ABOUT 10SM NORTH OF CAMP
PENDLETON. EXPECT THIS LAYER TO BECOME SCATTERED-FEW BETWEEN
1600-1700 UTC AND INCREASE BACK TO BROKEN AFTER 0600 UTC. OVER
MOUNTAINS AND DESERTS SCATTERED-BROKEN CLOUDS BETWEEN FL100-FL160 TO
CONTINUE FOR ANOTHER 24-36 HOURS. AIR MASS UNSTABLE ENOUGH BETWEEN
1800-0300 UTC TO SUPPORT SCATTERED THUNDERSTORMS WITH TOPS TO
FL430.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...JAD
AVIATION...BALFOUR
000
FXUS66 KLOX 021204
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
500 AM PDT THU JUL 2 2009
...UPDATED AVIATION SECTION...
.SYNOPSIS...
PERSISTENT ONSHORE FLOW WILL KEEP THE NIGHT THROUGH MORNING MARINE
CLOUD PATTERN GOING THROUGH THE FORECAST PERIOD. ONE LAST DAY TODAY
WITH A SLIGHT CHANCE OF A THUNDERSTORM IN THE MOUNTAINS AND DESERTS.
AN UNEVENTFUL SOUTHWEST FLOW PATTERN WILL OTHERWISE KEEP TEMPS NEAR
NORMAL.
&&
.SHORT TERM (TODAY-SAT)...
A 1200 FT MARINE LAYER WILL BRING LOW CLOUDS TO THE COASTS AND
PATCHY LOW CLOUDS TO THE COASTAL VLYS TODAY. LOW CLOUDS WILL ALSO
LIKELY AFFECT PASO ROBLES AS A 900 FOOT CLOUD DECK IS QUICKLY MOVING
DOWN THE SALINAS RIVER VLY. ABOVE THE MARINE LAYER SKIES BE SUNNY.
NAM SOUNDINGS SHOW SOME MID LEVEL MOISTURE AS WELL AS A LITTLE
INSTABILITY AND LOTS OF JULY SUNSHINE SO A SLIGHT CHC OF TSTMS LOOKS
GOOD...ONLY A SLIGHT CHC THOUGH AS OTHER CONVECTIVE PARAMETERS ARE
NOT LOOKING VERY GOOD. MAX TEMPS TODAY WILL BE CLOSE TO YDYS VALUES
A COUPLE OF DEGREES BELOW NORMALS COASTS AND VLYS AND ABOUT NORMAL
INLAND.
THE BIG CHANGE FOR FRIDAY WILL BE THE SHIFT OF THE FLOW PATTERN FROM
SOUTH TO SOUTHWEST AS THE FOUR CORNERS HIGH NUDGES EASTWARD. THIS
WILL END ANY CHANCE OF TSTMS. HGTS ARE A LITTLE HIGHER THAN
PREVIOUSLY FCST AND THIS WILL KEEP THE MARINE LAYER SMOOSHED AND
MOSTLY LIMITED TO THE COASTAL SITES AS WELL AS KEEPING INLAND TEMPS
WARMER THAN PREVIOUSLY THOUGHT.
NOT MUCH CHANGE FOR SATURDAY AS THE ENTIRE PATTERN ACROSS THE CONUS
IS FAIRLY STATIC. LOOK FOR A REPEAT OF FRIDAY. THIS IS A LITTLE
DIFFERENT THAN PREVIOUS THINKING WHICH CALLED FOR A BETTER MARINE
LAYER AND LOWER HGTS INDUCED BY AN APPROACHING TROF.
.LONG TERM (SUN-WED)...
BOTH GFS AND EC NOW AGREE THAT THE TROF THAT WAS SUPPOSED TO AFFECT
THE STATE OVER THE WEEKEND WILL HOLD OFF UNTIL AT LEAST TUESDAY.
THIS KEEPS THE PATTERN FAIRLY STATIC THROUGH MONDAY AND BOTH SUNDAY
AND MONDAY WILL BE VERY SIMILAR TO JULY FOURTH WITH MORNING LOW
CLOUDS OVER THE COASTS AND SOME OF THE VLYS MAX TEMPS WILL BE CLOSE
TO NORMALS PROBABLY A DEGREE OR TWO BELOW NORMAL ALONG THE COAST.
THE TROF IS FORECAST TO MOVE CLOSER AND SHARPEN SOMEWHAT TUESDAY OR
WEDNESDAY. THIS WILL INCREASE THE MARINE LAYER INTO THE VLYS. LOWER
HGTS WILL ALSO ALLOW THE INTERIOR TO COOL SOME.
&&
.AVIATION...02/0550Z.
PATCHY MARINE LAYER SHOULD COVER ALL COASTAL SITES LATER WITHIN A
COUPLE HOURS...THEN LIKELY CLEAR BETWEEN 16Z AND 18Z. THERE IS A
SLIGHT CHANCE OF TSTMS AROUND KPMD AND KWJF BETWEEN 21Z AND 04Z THIS
AFTERNOON. EXPECT ANOTHER PATCHY MARINE LAYER TONIGHT...WITH VERY
LITTLE CONFIDENCE IN ARRIVAL TIMES. AT THE LEAST...CIGS SHOULD HOLD
OFF UNTIL AFTER 06Z.
KLAX...MODERATE CONFIDENCE IN CURRENT TAF. HIGH CONFIDENCE IN
BURNOFF WITHIN AN HOUR OF FORECAST. LESS CONFIDENCE IN ARRIVAL TIMES
TONIGHT...BUT SHOULD BE IN IFR RANGE.
KBUR...VERY GOOD CONFIDENCE IN TAF...WITH VFR SKIES THROUGH THE
PERIOD.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...MEIER
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS66 KMTR 021158
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
500 AM PDT THU JUL 2 2009
UPDATED AVIATION DISCUSSION
.DISCUSSION...AS OF 3:25 AM PDT THURSDAY...FOG IMAGERY IS INDC THAT
THE STRATUS HAS MOVED WELL INLAND...THROUGH MOST OF THE NORTH BAY AND
DOWN THE SALINAS VALLEY. THE FORT ORD PROFILER IS INDC THAT THE
MARINE LAYER IS AROUND 2000 FEET. TEMPS THIS MORNING ARE MAINLY IN
THE 50S...WITH 60S AND 70S IN THE HILLS ABOVE THE MARINE LAYER. THE
GRADIENT PICTURE IS INDC A NEARLY FLAT GRADIENT BETWEEN ARCATA-SFO...
ONLY 0.5 MB AND A GOOD ONSHORE GRADIENT BETWEEN SFO-SAC OF 3.1 MB.
THE LAST TWO RUNS OF THE NAM12 (00Z AND 06Z) WERE MUCH DRIER IN THE
MID LEVELS...BASICALLY SHUNTING ANY MID LEVEL MOISTURE TO THE SOUTH
AND EAST OF THE DISTRICT. THIS FOLLOWS THE 00Z/06Z GFS AND THE 00Z
ECMWF. WV IMAGERY IS INDC PLENTY OF DRY AIR AT THE MID LEVELS MOVING
INTO THE DISTRICT...AND THE GOES HIGH DENSITY WINDS ARE OUT OF THE
SOUTH AND SOUTHWEST. BASED ON SATL IMAGERY AND MODEL DATA HAVE
REMOVED ANY MENTION OF THUNDER IN THE ZONES.
WEAK TROUGHING WILL CONTINUE THE NIGHT/MORNING LOW CLOUDS LOCALLY
INLAND...BURNING OFF TO THE COAST BY AFTERNOON RIGHT THRU FRIDAY.
BASICALLY...LITTLE CHANGE IS EXPECTED. A TROUGH GRADUALLY DEEPENS
ALONG THE COAST OVER THE HOLIDAY WEEKEND AND RIGHT THRU THE MIDDLE OF
NEXT WEEK. THIS TROUGH WILL BE UNUSUALLY DEEP OVER THE WEST COAST
WITH HEIGHTS NEAR 570 DM IN THE DISTRICT. COOLING IS EXPECTED
INLAND...BUT THE REAL QUESTION WILL BE THE MARINE INVERSION...WILL IT
MIX OUT. THE GFS ACTUALLY DROPS 850 MB TEMPS BELOW 10C BY WEDNESDAY
MORNING IN THE NORTH BAY...WHICH WOULD WIPE OUT THE MARINE INVERSION.
THE ECMWF IS ABOUT 2-4C WARMER...WHICH WOULD STILL LEAVE A MARINE
INVERSION ACROSS THE DISTRICT. HAVE OPTED FOR THE ECMWF SOLUTION AND
HAVE KEPT IN THE MARINE INVERSION. THIS WOULD ALSO HAVE AN EFFECT ON
COASTAL TEMPS...IF THE STRATUS IS MIXED OUT THEN THE COAST COULD BE A
BIT WARMER THAN FORECAST. THIS WILL NEED TO BE WATCHED AS THE WEEKEND
APPROACHES.
&&
.AVIATION...AS OF 5:00 AM PDT THURSDAY...WITH WEAK LOW
PRESSURE OFF THE CALIFORNIA COAST LIGHT SOUTHERLY WIND FLOW CONTINUES
OVER THE CENTRAL CALIFORNIA COASTLINE. COMBINED WITH MODERATE
ONSHORE PRESSURE GRADIENTS...THE WEAK COASTAL SOUTHERLY FLOW BRINGS
STRATUS INTO SOUTHERN MRY BAY EARLY AND THEN BRINGS STRATUS INTO
THE SAN FRANCISCO BAY SLIGHTLY DELAYED.
VICINITY OF KSFO...STRATUS IS FILLING INTO THE BAY WITH HIGH IFR/LOW
VFR CIGS. BASES VARY FROM 700-1100 FT MSL AND EXPECTED TO PERSIST
UNTIL 1730Z. HIGH IFR/LOW VFR CIGS ARE AGAIN EXPECTED TO
PUSH BACK INTO THE BAY BY 08Z TONIGHT.
KSFO BRIDGE APPROACH...STRATUS WITH CIGS011-014 OVER THE BAY AND
IMPROVING TO SCT AROUND 1715Z.
MONTEREY BAY TERMINALS...IFR CIGS 6-8 HND FT MSL BURNING BACK TO THE
COAST AROUND 18Z. HIGH IFR CIGS IN STRATUS RETURNING AFT 04Z THIS
EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: MHS
AVIATION/MARINE: GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KEKA 021155
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
455 AM PDT THU JUL 2 2009
.SYNOPSIS...A WEAK LOW OFFSHORE MAY PRODUCE THUNDERSTORMS OVER
INTERIOR PORTIONS OF NORTHWEST CALIFORNIA THIS AFTERNOON AND EARLY
THIS EVENING. THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE FRIDAY
AFTERNOON AS THE LOW DRIFTS TO THE EAST OF THE AREA.
MEANWHILE...THE COAST WILL CONTINUE TO EXPERIENCE CLOUDS AND FOG.
&&
.DISCUSSION...THE MAIN THREAT TODAY WILL ONCE AGAIN BE DRY
THUNDERSTORMS INLAND. WATER VAPOR IMAGERY SHOWS A WEAK LOW JUST
OFF THE CENTRAL CALIFORNIA COAST SLOWLY DRIFTING TOWARDS THE
NORTHEAST. ALSO SEEN IS THE AREA OF MOISTURE WHERE YESTERDAYS
THUNDERSTORMS FORMED OVER OUR AREA. THIS MOISTURE HAS NOT MOVED
MUCH AND REMAINS OVER THE NORTHERN PART OF OUR CWA. ANOTHER AREA
OF MOISTURE OVER CENTRAL CALIFORNIA IS MOVING TO THE NORTH AND
WILL BE NEAR OR OVER THE AREA IN THE UPCOMING HOURS. ONCE
AGAIN...SLIGHTLY ABOVE NORMAL TEMPERATURES OVER THE INLAND
LOCATIONS COMBINED WITH THE MOISTURE AND INSTABILITY ASSOCIATED
WITH THE APPROACHING LOW WILL BRING THE POTENTIAL FOR
THUNDERSTORMS TO INLAND LOCATIONS THIS AFTERNOON INTO EARLY THIS
EVENING. THE GFS MODEL SHOWS INLAND AFTERNOON LI`S OF -2...MU CAPES
NEAR 200 AND PRECIPITABLE WATER UP TO 0.75 INCH. SOME OF THESE
NUMBERS ARE SLIGHTLY LOWER THAN YESTERDAY. WHAT IS IMPORTANT TO
NOTE IS THE MODEL ALSO SHOWS LI`S OF -4...MU CAPES APPROACHING 1200
AND PRECIPITABLE WATER UP TO 1 INCH JUST TO OUR NORTHEAST. BASED
ON THE WATER VAPOR IMAGERY IT LOOKS LIKE THE MODELS HAVE THE
MOISTURE AND ASSOCIATED INSTABILITY JUST A TAD TO FAR TO THE
NORTH. THIS MEANS THE MODELS MAY BE UNDER DOING THE THUNDERSTORM
POTENTIAL. THE MODELS ALSO SEEM LIKE THEY MAY BE UNDER DOING THE
INSTABILITY ASSOCIATED WITH THE MOISTURE ADVECTING TOWARDS THE
AREA FROM OUR SOUTH. SREF PROBABILITIES OF NEGATIVE LI`S ARE OVER
90 PERCENT FOR A MAJORITY OF OUR AREA THIS AFTERNOON AND THE SPC
HAS MOST OF OUR AREA UNDER A GENERAL RISK OF THUNDERSTORMS. GIVEN
ALL THAT...FEEL THAT INLAND LOCATIONS WILL PROBABLY SEE SCATTERED
THUNDERSTORMS THIS AFTERNOON INTO EARLY THIS EVENING. ONCE AGAIN
THE LIMITED MOISTURE MEANS ANY THUNDERSTORMS THAT FORM WILL
PROBABLY BE DRY SO DRY LIGHTNING IS A CONCERN. FRIDAY THE LOW WILL
STILL BE IN OUR GENERAL AREA AND MODELS SHOW SOME MOISTURE AND
INSTABILITY OVER OUR EASTERNMOST CWA. SO ADJUSTED THE FORECAST A
LITTLE TO SHOW SCATTERED THUNDERSTORMS FOR THE TIP OF TRINITY
COUNTY FOR FRIDAY AFTERNOON.
THE 4TH LOOKS LIKE IT WILL BE DRY INLAND WITH TEMPERATURES SLIGHTLY
ABOVE NORMAL. THE COAST WILL SEE STRATUS...FOG AND PATCHY
DRIZZLE...WHICH COULD MAKE ANY FIREWORKS DISPLAYS ALONG THE COAST A
LITTLE DIFFICULT TO SEE. A LONG WAVE TROUGH WILL BEGIN TO MOVE OVER
THE WEST COAST EARLY NEXT WEEK...BRINGING COOLER TEMPERATURES. STROZ
&&
.AVIATION...FOG PRODUCT IMAGERY SHOWS THE ENTIRE COAST ENGULFED IN
MARINE STRATUS...WITH COASTAL OBSERVATIONS REPORTING LIFR
VISIBILITIES AND CEILINGS. 12Z MODEL RUNS ARE NOT DEPICTING THE
STRATUS VERY WELL. WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
DAY WITH THE STRATUS LINGERING ALONG THE COAST. VISIBILITIES SHOULD
IMPROVE IN THE AFTERNOON WITH LIFR CONDITIONS RETURNING IN THE
EVENING. VFR CONDITIONS WILL PREVAIL INLAND WITH A FEW HIGH BASED
THUNDERSTORMS AND CUMULUS OVER THE HIGHER TERRAIN THIS AFTERNOON AND
EARLY EVENING. TH
&&
.MARINE...CALM WINDS WILL PERSIST THROUGH THE WEEKEND AS WEAK LOW
PRESSURE OVER THE AREA WILL MAINTAIN A WEAK PRESSURE GRADIENT ACROSS
THE WATERS. THE SEAS WILL CONTINUE TO SUBSIDE TODAY WITH SMALL CRAFT
SEAS REMAINING BEYOND 10 NM AROUND AND NORTH OF CAPE MENDOCINO
THROUGH LATE TONIGHT. LOW MIXED SEAS WILL PERSIST INTO NEXT WEEK...
WITH A SMALL LONG PERIOD SOUTH SWELL AND A SMALL SHORT PERIOD
NORTHWEST SWELL PROPAGATING THROUGH THE WATERS. TH
&&
.FIRE WEATHER...A WEAK LOW OFF THE COAST WILL SLOWLY DRIFT TOWARD
THE DISTRICT TODAY AND WILL BE LOCATED EAST OF THE AREA LATE
FRIDAY. ALTHOUGH MOISTURE IS LIMITED WITH THIS LOW...EXPECT
SCATTERED DRY THUNDERSTORMS TO FORM OVER THE HIGHER TERRAIN OF THE
INTERIOR IN THE AFTERNOON AND EARLY EVENING TODAY AND SCATTERED
DRY THUNDERSTORMS FOR TRINITY COUNTY FRIDAY AFTERNOON. A TROUGH
MOVING OVER THE WEST COAST EARLY NEXT WEEK WILL BRING THE DISTRICT
COOLER TEMPERATURES. STROZ
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SCA FOR HAZ SEAS FROM PT ST GEORGE TO CAPE MENDOCINO 10 TO 60 NM.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
000
FXUS66 KMTR 021046
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
346 AM PDT THU JUL 2 2009
.DISCUSSION...AS OF 3:25 AM PDT THURSDAY...FOG IMAGERY IS INDC THAT
THE STRATUS HAS MOVED WELL INLAND...THROUGH MOST OF THE NORTH BAY AND
DOWN THE SALINAS VALLEY. THE FORT ORD PROFILER IS INDC THAT THE
MARINE LAYER IS AROUND 2000 FEET. TEMPS THIS MORNING ARE MAINLY IN
THE 50S...WITH 60S AND 70S IN THE HILLS ABOVE THE MARINE LAYER. THE
GRADIENT PICTURE IS INDC A NEARLY FLAT GRADIENT BETWEEN ARCATA-SFO...
ONLY 0.5 MB AND A GOOD ONSHORE GRADIENT BETWEEN SFO-SAC OF 3.1 MB.
THE LAST TWO RUNS OF THE NAM12 (00Z AND 06Z) WERE MUCH DRIER IN THE
MID LEVELS...BASICALLY SHUNTING ANY MID LEVEL MOISTURE TO THE SOUTH
AND EAST OF THE DISTRICT. THIS FOLLOWS THE 00Z/06Z GFS AND THE 00Z
ECMWF. WV IMAGERY IS INDC PLENTY OF DRY AIR AT THE MID LEVELS MOVING
INTO THE DISTRICT...AND THE GOES HIGH DENSITY WINDS ARE OUT OF THE
SOUTH AND SOUTHWEST. BASED ON SATL IMAGERY AND MODEL DATA HAVE
REMOVED ANY MENTION OF THUNDER IN THE ZONES.
WEAK TROUGHING WILL CONTINUE THE NIGHT/MORNING LOW CLOUDS LOCALLY
INLAND...BURNING OFF TO THE COAST BY AFTERNOON RIGHT THRU FRIDAY.
BASICALLY...LITTLE CHANGE IS EXPECTED. A TROUGH GRADUALLY DEEPENS
ALONG THE COAST OVER THE HOLIDAY WEEKEND AND RIGHT THRU THE MIDDLE OF
NEXT WEEK. THIS TROUGH WILL BE UNUSUALLY DEEP OVER THE WEST COAST
WITH HEIGHTS NEAR 570 DM IN THE DISTRICT. COOLING IS EXPECTED
INLAND...BUT THE REAL QUESTION WILL BE THE MARINE INVERSION...WILL IT
MIX OUT. THE GFS ACTUALLY DROPS 850 MB TEMPS BELOW 10C BY WEDNESDAY
MORNING IN THE NORTH BAY...WHICH WOULD WIPE OUT THE MARINE INVERSION.
THE ECMWF IS ABOUT 2-4C WARMER...WHICH WOULD STILL LEAVE A MARINE
INVERSION ACROSS THE DISTRICT. HAVE OPTED FOR THE ECMWF SOLUTION AND
HAVE KEPT IN THE MARINE INVERSION. THIS WOULD ALSO HAVE AN EFFECT ON
COASTAL TEMPS...IF THE STRATUS IS MIXED OUT THEN THE COAST COULD BE A
BIT WARMER THAN FORECAST. THIS WILL NEED TO BE WATCHED AS THE WEEKEND
APPROACHES.
&&
.AVIATION...AS OF 10:30 PM PDT WEDNESDAY...SOUTHERLY FLOW CONTINUES
ALONG THE COAST. THIS BRINGS STRATUS INTO SOUTHERN MRY BAY
EARLY WHILE HOLDING OFF UNTIL LATE TONIGHT IN THE SFO BAY AREA.
VICINITY OF KSFO...STRATUS WILL FILL IN OVER THE BAY LATER
TONIGHT WITH CEILINGS BY 08-09Z. BASES WILL ONCE AGAIN BE IN THE
1000-1400 FEET RANGE THROUGH 17-18Z TOMORROW.
KSFO BRIDGE APPROACH...EXPECT STRATUS AGAIN TONIGHT WITH CEILINGS BY
08-09Z.
MONTEREY BAY TERMINALS...STRATUS WITH BASES STARTING OUT OUT AT
1000-1500 FEET WILL THEN LOWER TO 500-1000 FEET LATER TONIGHT.
CLEARING TO THE BAY BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDY...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: MHS
AVIATION/MARINE: W PI/GUDGEL
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 021036
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
330 AM PDT THU JUL 2 2009
.SYNOPSIS...
PERSISTENT ONSHORE FLOW WILL KEEP THE NIGHT THROUGH MORNING MARINE
CLOUD PATTERN GOING THROUGH THE FORECAST PERIOD. ONE LAST DAY TODAY
WITH A SLIGHT CHANCE OF A THUNDERSTORM IN THE MOUNTAINS AND DESERTS.
AN UNEVENTFUL SOUTHWEST FLOW PATTERN WILL OTHERWISE KEEP TEMPS NEAR
NORMAL.
&&
.SHORT TERM (TODAY-SAT)...
A 1200 FT MARINE LAYER WILL BRING LOW CLOUDS TO THE COASTS AND
PATCHY LOW CLOUDS TO THE COASTAL VLYS TODAY. LOW CLOUDS WILL ALSO
LIKELY AFFECT PASO ROBLES AS A 900 FOOT CLOUD DECK IS QUICKLY MOVING
DOWN THE SALINAS RIVER VLY. ABOVE THE MARINE LAYER SKIES BE SUNNY.
NAM SOUNDINGS SHOW SOME MID LEVEL MOISTURE AS WELL AS A LITTLE
INSTABILITY AND LOTS OF JULY SUNSHINE SO A SLIGHT CHC OF TSTMS LOOKS
GOOD...ONLY A SLIGHT CHC THOUGH AS OTHER CONVECTIVE PARAMETERS ARE
NOT LOOKING VERY GOOD. MAX TEMPS TODAY WILL BE CLOSE TO YDYS VALUES
A COUPLE OF DEGREES BELOW NORMALS COASTS AND VLYS AND ABOUT NORMAL
INLAND.
THE BIG CHANGE FOR FRIDAY WILL BE THE SHIFT OF THE FLOW PATTERN FROM
SOUTH TO SOUTHWEST AS THE FOUR CORNERS HIGH NUDGES EASTWARD. THIS
WILL END ANY CHANCE OF TSTMS. HGTS ARE A LITTLE HIGHER THAN
PREVIOUSLY FCST AND THIS WILL KEEP THE MARINE LAYER SMOOSHED AND
MOSTLY LIMITED TO THE COASTAL SITES AS WELL AS KEEPING INLAND TEMPS
WARMER THAN PREVIOUSLY THOUGHT.
NOT MUCH CHANGE FOR SATURDAY AS THE ENTIRE PATTERN ACROSS THE CONUS
IS FAIRLY STATIC. LOOK FOR A REPEAT OF FRIDAY. THIS IS A LITTLE
DIFFERENT THAN PREVIOUS THINKING WHICH CALLED FOR A BETTER MARINE
LAYER AND LOWER HGTS INDUCED BY AN APPROACHING TROF.
.LONG TERM (SUN-WED)...
BOTH GFS AND EC NOW AGREE THAT THE TROF THAT WAS SUPPOSED TO AFFECT
THE STATE OVER THE WEEKEND WILL HOLD OFF UNTIL AT LEAST TUESDAY.
THIS KEEPS THE PATTERN FAIRLY STATIC THROUGH MONDAY AND BOTH SUNDAY
AND MONDAY WILL BE VERY SIMILAR TO JULY FOURTH WITH MORNING LOW
CLOUDS OVER THE COASTS AND SOME OF THE VLYS MAX TEMPS WILL BE CLOSE
TO NORMALS PROBABLY A DEGREE OR TWO BELOW NORMAL ALONG THE COAST.
THE TROF IS FORECAST TO MOVE CLOSER AND SHARPEN SOMEWHAT TUESDAY OR
WEDNESDAY. THIS WILL INCREASE THE MARINE LAYER INTO THE VLYS. LOWER
HGTS WILL ALSO ALLOW THE INTERIOR TO COOL SOME.
&&
.AVIATION...
02/1130Z.
OUT WITH 12Z TAFS
KLAX...
KBUR...
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...MEIER
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 021036
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
335 AM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
MOIST MONSOONAL FLOW CONTINUES EARLY THIS MORNING ACROSS MOST OF OUR
CWA...AND THE IR/VAPOR IMAGERY NICELY DEPICT THE WHITE PLUME OF DEEP
MOISTURE PUSHING NORTH OUT OF MEXICO AND ACROSS ARIZONA. 500MB HIGH
CENTERED NEAR THE FOUR CORNERS HAS ALLOWED A SLY TO SELY STEERING
FLOW TO SPREAD THIS MOISTURE OVER OUR CWA. WEAK SHORT WAVE EMBEDDED
IN THE PLUME WAS COMBINING WITH BOUNDARY INTERACTIONS TO ALLOW ISOLD
TO SCATTERED SHOWERS AND THUNDERSTORMS TO FORM ACROSS SOUTH-CENTRAL
AND EVEN PARTS OF SOUTHWEST ARIZONA EARLY THIS MORNING. PARTLY BASED
ON SHOWERS/STORMS IN THE AREA AS WELL AS MOIST LOW LEVEL OUTFLOWS...
SURFACE DEWPOINTS ACROSS OUR LOWER DESERTS ARE ALSO RATHER HIGH AT 2
AM...AND WERE RUNNING IN THE UPPER 50S TO UPPER 60S MOST PLACES.
LATEST PROGS ACTUALLY AGREE ON A FEW THINGS THIS MORNING...THE MOST
SIGNIFICANT BEING THAT THE UPPER HIGH WILL SHIFT A BIT TO THE
EAST...AND THE FLOW ALOFT WILL BECOME SWLY WITH TIME TODAY THRU
FRIDAY. SWLY FLOW ALOFT IS NOT VERY FAVORABLE TO BRING STORMS INTO
OUR LOWER DESERTS. NAM/GFS ALSO DO NOT CALL FOR ANY SIGNIFICANT
TRIGGERS/SHORT WAVES TO EXIST IN THE SLY/SWLY FLOW...KEEPING THE
FLOW MORE LAMINAR AND REDUCING POTENTIAL FOR DYNAMICS AND UPPER
FORCING. PROGS ALSO SUGGEST THAT SOME OF THE DEEPER MOISTURE TODAY
WILL FOCUS OVER OUR WESTERN CWA...WITH SOMEWHAT DRIER MORE STABLE
AIR TO EXIST FROM PHOENIX EASTWARD. GIVEN THE POOR STEERING FLOW AND
SOMEWHAT LIMITED INSTABILTY TODAY...WILL CALL FOR JUST A SLIGHT
CHANCE FOR MAINLY AFTERNOON AND EVENING STORMS OVER THE SERN CA AND
LOWER AZ DESERTS...AND KEEP CHANCE POPS CONFINED TO HIGHER TERRAIN
OF ZONE 24. SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS
LOWERED JUST A FEW PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL
NORMALS EACH DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS
PERSIST WELL INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINDED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
THUNDERSTORM ACTIVITY WILL CONTINUE TO DIMINISH THIS MORNING OVER
THE AREA...SOME ACTIVITY WILL CONTINUE OVER THE OPEN DESERTS WEST OF
LUKE AFB UNTIL SUNRISE...WITH LINGERING DEBRIS CLOUDINESS THE REST
OF THE MORNING. EASTERLY WINDS WILL PERSIST AT KPHX/KIWA THROUGH 18Z
...THEN WINDS BECOME WEST-SOUTHWESTERLY INTO THE AFTERNOON HOURS.
THUNDERSTORM POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT
LOOK SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL
HELP REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP OVER THE HIGHER TERRAIN NORTH AND EAST OF KPHX/KIWA.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
SOME AREAS OF MID AND HIGH CLOUDINESS WILL SLOWLY DISSIPATE THIS
MORNING. ISOLATED STORM DEVELOPMENT WILL BEGIN THURSDAY AFTERNOON
...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...VLM
FIRE WEATHER...VLM
000
FXUS66 KLOX 021036
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
330 AM PDT THU JUL 2 2009
.SYNOPSIS...
PERSISTENT ONSHORE FLOW WILL KEEP THE NIGHT THROUGH MORNING MARINE
CLOUD PATTERN GOING THROUGH THE FORECAST PERIOD. ONE LAST DAY TODAY
WITH A SLIGHT CHANCE OF A THUNDERSTORM IN THE MOUNTAINS AND DESERTS.
AN UNEVENTFUL SOUTHWEST FLOW PATTERN WILL OTHERWISE KEEP TEMPS NEAR
NORMAL.
&&
.SHORT TERM (TODAY-SAT)...
A 1200 FT MARINE LAYER WILL BRING LOW CLOUDS TO THE COASTS AND
PATCHY LOW CLOUDS TO THE COASTAL VLYS TODAY. LOW CLOUDS WILL ALSO
LIKELY AFFECT PASO ROBLES AS A 900 FOOT CLOUD DECK IS QUICKLY MOVING
DOWN THE SALINAS RIVER VLY. ABOVE THE MARINE LAYER SKIES BE SUNNY.
NAM SOUNDINGS SHOW SOME MID LEVEL MOISTURE AS WELL AS A LITTLE
INSTABILITY AND LOTS OF JULY SUNSHINE SO A SLIGHT CHC OF TSTMS LOOKS
GOOD...ONLY A SLIGHT CHC THOUGH AS OTHER CONVECTIVE PARAMETERS ARE
NOT LOOKING VERY GOOD. MAX TEMPS TODAY WILL BE CLOSE TO YDYS VALUES
A COUPLE OF DEGREES BELOW NORMALS COASTS AND VLYS AND ABOUT NORMAL
INLAND.
THE BIG CHANGE FOR FRIDAY WILL BE THE SHIFT OF THE FLOW PATTERN FROM
SOUTH TO SOUTHWEST AS THE FOUR CORNERS HIGH NUDGES EASTWARD. THIS
WILL END ANY CHANCE OF TSTMS. HGTS ARE A LITTLE HIGHER THAN
PREVIOUSLY FCST AND THIS WILL KEEP THE MARINE LAYER SMOOSHED AND
MOSTLY LIMITED TO THE COASTAL SITES AS WELL AS KEEPING INLAND TEMPS
WARMER THAN PREVIOUSLY THOUGHT.
NOT MUCH CHANGE FOR SATURDAY AS THE ENTIRE PATTERN ACROSS THE CONUS
IS FAIRLY STATIC. LOOK FOR A REPEAT OF FRIDAY. THIS IS A LITTLE
DIFFERENT THAN PREVIOUS THINKING WHICH CALLED FOR A BETTER MARINE
LAYER AND LOWER HGTS INDUCED BY AN APPROACHING TROF.
.LONG TERM (SUN-WED)...
BOTH GFS AND EC NOW AGREE THAT THE TROF THAT WAS SUPPOSED TO AFFECT
THE STATE OVER THE WEEKEND WILL HOLD OFF UNTIL AT LEAST TUESDAY.
THIS KEEPS THE PATTERN FAIRLY STATIC THROUGH MONDAY AND BOTH SUNDAY
AND MONDAY WILL BE VERY SIMILAR TO JULY FOURTH WITH MORNING LOW
CLOUDS OVER THE COASTS AND SOME OF THE VLYS MAX TEMPS WILL BE CLOSE
TO NORMALS PROBABLY A DEGREE OR TWO BELOW NORMAL ALONG THE COAST.
THE TROF IS FORECAST TO MOVE CLOSER AND SHARPEN SOMEWHAT TUESDAY OR
WEDNESDAY. THIS WILL INCREASE THE MARINE LAYER INTO THE VLYS. LOWER
HGTS WILL ALSO ALLOW THE INTERIOR TO COOL SOME.
&&
.AVIATION...
02/1130Z.
OUT WITH 12Z TAFS
KLAX...
KBUR...
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...MEIER
SYNOPSIS...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 021036
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
335 AM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
MOIST MONSOONAL FLOW CONTINUES EARLY THIS MORNING ACROSS MOST OF OUR
CWA...AND THE IR/VAPOR IMAGERY NICELY DEPICT THE WHITE PLUME OF DEEP
MOISTURE PUSHING NORTH OUT OF MEXICO AND ACROSS ARIZONA. 500MB HIGH
CENTERED NEAR THE FOUR CORNERS HAS ALLOWED A SLY TO SELY STEERING
FLOW TO SPREAD THIS MOISTURE OVER OUR CWA. WEAK SHORT WAVE EMBEDDED
IN THE PLUME WAS COMBINING WITH BOUNDARY INTERACTIONS TO ALLOW ISOLD
TO SCATTERED SHOWERS AND THUNDERSTORMS TO FORM ACROSS SOUTH-CENTRAL
AND EVEN PARTS OF SOUTHWEST ARIZONA EARLY THIS MORNING. PARTLY BASED
ON SHOWERS/STORMS IN THE AREA AS WELL AS MOIST LOW LEVEL OUTFLOWS...
SURFACE DEWPOINTS ACROSS OUR LOWER DESERTS ARE ALSO RATHER HIGH AT 2
AM...AND WERE RUNNING IN THE UPPER 50S TO UPPER 60S MOST PLACES.
LATEST PROGS ACTUALLY AGREE ON A FEW THINGS THIS MORNING...THE MOST
SIGNIFICANT BEING THAT THE UPPER HIGH WILL SHIFT A BIT TO THE
EAST...AND THE FLOW ALOFT WILL BECOME SWLY WITH TIME TODAY THRU
FRIDAY. SWLY FLOW ALOFT IS NOT VERY FAVORABLE TO BRING STORMS INTO
OUR LOWER DESERTS. NAM/GFS ALSO DO NOT CALL FOR ANY SIGNIFICANT
TRIGGERS/SHORT WAVES TO EXIST IN THE SLY/SWLY FLOW...KEEPING THE
FLOW MORE LAMINAR AND REDUCING POTENTIAL FOR DYNAMICS AND UPPER
FORCING. PROGS ALSO SUGGEST THAT SOME OF THE DEEPER MOISTURE TODAY
WILL FOCUS OVER OUR WESTERN CWA...WITH SOMEWHAT DRIER MORE STABLE
AIR TO EXIST FROM PHOENIX EASTWARD. GIVEN THE POOR STEERING FLOW AND
SOMEWHAT LIMITED INSTABILTY TODAY...WILL CALL FOR JUST A SLIGHT
CHANCE FOR MAINLY AFTERNOON AND EVENING STORMS OVER THE SERN CA AND
LOWER AZ DESERTS...AND KEEP CHANCE POPS CONFINED TO HIGHER TERRAIN
OF ZONE 24. SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS
LOWERED JUST A FEW PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL
NORMALS EACH DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS
PERSIST WELL INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINDED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
THUNDERSTORM ACTIVITY WILL CONTINUE TO DIMINISH THIS MORNING OVER
THE AREA...SOME ACTIVITY WILL CONTINUE OVER THE OPEN DESERTS WEST OF
LUKE AFB UNTIL SUNRISE...WITH LINGERING DEBRIS CLOUDINESS THE REST
OF THE MORNING. EASTERLY WINDS WILL PERSIST AT KPHX/KIWA THROUGH 18Z
...THEN WINDS BECOME WEST-SOUTHWESTERLY INTO THE AFTERNOON HOURS.
THUNDERSTORM POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT
LOOK SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL
HELP REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP OVER THE HIGHER TERRAIN NORTH AND EAST OF KPHX/KIWA.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
SOME AREAS OF MID AND HIGH CLOUDINESS WILL SLOWLY DISSIPATE THIS
MORNING. ISOLATED STORM DEVELOPMENT WILL BEGIN THURSDAY AFTERNOON
...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...VLM
FIRE WEATHER...VLM
000
FXUS66 KSTO 021020
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
300 AM PDT THU JUL 02 2009
.DISCUSSION...
GENERALLY WARM AND INCREASINGLY PLEASANT WEATHER IS IN STORE FOR
MUCH OF THE DISTRICT FOR THE NEXT SEVERAL DAYS. ISOLATED LATE DAY
THUNDERSTORMS ARE POSSIBLE OVER THE SIERRA NEVADA RANGE TODAY AND
AGAIN ON FRIDAY. THE GREATEST POTENTIAL WILL BE FROM INTERSTATE 80
NORTHWARD ALONG THE CREST. A COOLING TREND BEGINS LATER IN THE
WEEKEND AS AN UPPER LOW OVER THE EASTERN PACIFIC MOVES OVER THE
PACIFIC NORTHWEST. THE PROXIMITY OF THE LOW TO OUR AREA WILL MEAN
THAT BY MONDAY...DAYTIME TEMPERATURES WILL BE 5 TO 10 DEGREES COOLER
THAN NORMAL.
A THERMAL TROUGH ESTABLISHED OVER EASTERN PART OF THE AREA WILL
REMAIN IN A SIMILAR POSITION THURSDAY AFTERNOON BEFORE SHIFTING
SLIGHTLY EASTWARD ON FRIDAY. THIS WILL KEEP DELTA BREEZE SITUATION
TODAY SIMILAR TO WED...WITH A BIT MORE OF A DELTA BREEZE INFLUENCE
ON FRIDAY. DK2
.EXTENDED DISCUSSION (SUNDAY THRU WEDNESDAY)...
AN UPPER LOW APPROACHES THE PACIFIC NORTHWEST SUNDAY WITH SOME
SHORTWAVE ENERGY UNDERCUTTING THE MAIN LOW AND BRUSHING ACROSS
NORTHERN CALIFORNIA SUNDAY NIGHT INTO MONDAY. THEN THE MAIN LOW
CENTER ASSOCIATED WITH THE UPPER LOW SWINGS ACROSS NORTHERN
CALIFORNIA TUE WITH SHORT WAVES LINGERING THROUGH WED. THE MAIN
AFFECT ON OUR AREA WILL BE COOLER TEMPS BUT NO SIGNIFICANT THREAT OF
PRECIPITATION. AS THE MAIN LOW NEARS TUE INTO WED...A SLIGHT RISK OF
SHOWERS IN THE EXTREME NORTHERN PART OF THE AREA DEVELOPS.
HOWEVER...MOST FORECAST MODELS ARE INDICATING WITH MODERATE
CONFIDENCE THAT THE PATTERN WILL REMAIN RELATIVELY DRY. FOR NOW
HAVE UPPED POPS IN THE EXTENDED SLIGHTLY TO RIGHT AROUND
CLIMATOLOGICAL NORMALS. THE UPPER LOW WILL ENHANCE THE DELTA BREEZE
AT TIMES AS THE MARINE LAYER OFFSHORE DEEPENS IN RESPONSE TO THE
COOLER AIR ALOFT. DK2
&&
.AVIATION...
VFR CONDITIONS WITH AREAS OF MID LEVEL CLOUDS ARE EXPECTED OVER
INTERIOR NORTHERN CALIFORNIA THROUGH FRIDAY EXCEPT FOR CUMULUS
BUILDUP LEADING TO ISOLATED THUNDERSTORMS OVER THE MOUNTAINS WITH
POSSIBLE MVFR/IFR CONDITIONS IN THE AFTERNOONS AND EVENINGS. ONSHORE
FLOW CONTINUES WITH SOUTHWEST WIND GUSTS UP TO 35 KTS THROUGH THE
DELTA IN THE MORNINGS. STRATUS (MARINE LAYER AROUND 1800 FT DEEP)
AND IFR CONDITIONS IN THE INTERIOR COASTAL VLYS IN THE BAY AREA AND
NEAR THE STRAIT WILL DISSIPATE BY 17Z.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KREV 021006
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
305 AM PDT THU JUL 2 2009
.SHORT TERM...
THE UPPER TROUGH THAT IS OFF THE CALIFORNIA COAST THIS MORNING
SHOULD MOVE EAST AND MOVE ACROSS THE GREAT BASIN DURING THE NEXT FEW
DAYS. AS A RESULT THE WEATHER WILL BE UNSETTLED UNTIL THIS FEATURE
MOVES EAST OF THE REGION.
THE 00Z MODELS INITIALIZED WELL SHOWING THE WEAK TROUGH OFF THE WEST
COAST AND THE DEEPER UPPER TROUGH 50N 150W. THE NAM...GFS...UKMET
AND ECMWF ALL SHOW THE WEST COAST TROUGH WEAKENING TODAY AS THE
RIDGE OVER THE SWRN CONUS STRENGTHENS. THIS WILL PROVIDE MORE OF A
WLY FLOW OVER THE SIERRA AND WRN GREAT BASIN AND THIS IS SIMILAR TO
WHAT THE MODELS WERE SHOWING YESTERDAY. WARM SFC TEMPERATURES TODAY
WILL HELP TO INCREASE LLVL INSTABILITY. THE NAM HAS LIFTED INDEX
VALUES OF LESS THAN ZERO ACROSS THE ENTIRE WRN GREAT BASIN TODAY.
THE GFS IS NOT QUITE AS UNSTABLE BUT STILL HAS LIFTED INDICES OF
LESS THAN ZERO OVER ALL BUT THE NWRN THIRD OF THE KREV CWFA.
WITH THE SLY FLOW OVER THE REGION PRECIPITABLE WATER VALUES SHOULD
CONTINUE TO INCREASE TODAY. THE NAM SHOWS PWAT VALUES OF AT LEAST
0.50 INCH OVER THE ENTIRE CWFA TODAY. THE GFS IS EVEN MORE MOIST
WITH PWAT VALUES OF OVER 0.75 INCH ACROSS THE AREA TODAY AND
FRIDAY. WILL CONTINUE WITH ISOLD TO SCT TSTMS OVER THE CWFA TODAY.
INSTABILITY SHOULD BE SLIGHTLY LESS ON FRIDAY BUT WILL CONTINUE THE
CURRENT FCST OF A SLIGHT CHANCE OF AFTN AND EVENING TSTMS. DRY
CONDITIONS ARE EXPECTED ON SATURDAY AS THE UPPER TROUGH WEAKENS AND
MOVES EAST WITH HIGH PRESSURE BUILDING IN. TEMPERATURES WILL
CONTINUE A FEW DEGREES ABOVE NORMAL THROUGH THE SHORT TERM. O`HARA
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
MEDIUM RANGE MODELS CONTINUE ADVERTISE TROUGH NEXT WEEK WITH COOLER
TEMPERATURES AND PERIODS OF BREEZY TO LOCALLY WINDY CONDITIONS.
THERE ARE DIFFERENCES IN DETAIL WITH MODELS RANGING FROM HOLDING
TROUGH TO THE WEST OF AREA UNTIL LATE IN PERIOD (CANADIAN) TO A MORE
PROGRESSIVE SOLUTION IN THE GFS WHICH IS ONLY SLIGHTLY MORE SO THAN
THE DETERMINISTIC ECMWF. GIVEN THE AMOUNT OF AMPLIFICATION IN THE
LONGWAVE PATTERN...A SLOWER EVOLUTION IS PREFERRED. THIS ELIMINATES
THE GFS DETERMINISTIC RUN. AN ENSEMBLE APPROACH IS PREFERRED WHICH
SLOWS THE COOLING AND WILL LIKELY PROLONG THE BREEZY CONDITIONS.
TEMPERATURES NEAR NORMAL AT START OF PERIOD WILL GRADUALLY FALL TO
AS MUCH AS 10-12 DEGREES BELOW NORMAL BY WED. THE LOCATION OF THE
MEAN TROUGH AND JET FEATURES PLACE MUCH OF OUR AREA IN THE DRY AND
STABLE SIDE OF THE SYSTEM. THE EXCEPTION WILL BE FAR NORTHERN AREAS
WHERE A FEW LIGHT SHOWERS COULD WORK EASTWARD TUE-WED. VERY FEW
CHANGES WERE NEEDED TO PREVIOUS FORECAST PACKAGE. HOHMANN
&&
.AVIATION...
VFR CONDS TO PREVAIL WITH SCT-BKN CU-TCU AND ISOLD CB BTWN 20Z-03Z.
ISOLD-SCT HIGH-BASED -TSRA POSSIBLE 21Z-03Z MAINLY SOUTH OF KTVL AND
NORTH OF A SUSANVILLE-GERLACH LINE. GUSTY OUTFLOW WINDS TO 35 KTS
POSSIBLE NEAR STORMS...OTHERWISE LEE SIDE ZEPHYR BREEZES VCNTY KRNO
WITH GUSTS 20-25 KT BTWN 22Z-03Z. HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSGX 020950
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
300 AM PDT THU JUL 2 2009
.SYNOPSIS...FAIR WEATHER WILL CONTINUE WITH ENOUGH MOISTURE ALOFT TO
BRING A SLIGHT CHANCE OF THUNDERSTORMS IN THE MOUNTAINS AND DESERTS
THROUGH FRIDAY. MEANWHILE A SHALLOW MARINE LAYER WILL CONTINUE TO
BRING LOW CLOUDS AND FOG NEAR THE COAST EACH NIGHT AND MORNING.
DRIER AIR WILL MOVE INTO THE REGION AND END THE CHANCE OF
THUNDERSTORMS OVER THE HOLIDAY WEEKEND. HIGH PRESSURE WILL WEAKEN
GRADUALLY NEXT WEEK...WHICH WILL BRING COOLER WEATHER AND MORE
EXTENSIVE COASTAL CLOUDS.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
SOME OUTFLOW FROM ARIZONA THUNDERSTORMS HAVE BROUGHT SOME SPRINKLES
TO THE DESERT TOWARD THE COLORADO RIVER THIS MORNING...BUT NOTHING
VERY CLOSE TO OUR REGION. THE LOW CLOUDS HAVE MOVED INTO SAN DIEGO
COUNTY...BUT ARE SLOW TO COVER ORANGE COUNTY SO FAR. THE DEW POINTS
HAVE INCREASED INLAND OVER THE LAST DAY AND THERE WILL CONTINUE TO
BE MOISTURE STREAMING ALOFT. THIS WARRANTS THE SMALL CHANCES OF
SHOWERS AND THUNDERSTORMS...BUT THERE IS NO REAL TRIGGER MECHANISM
FOR WIDESPREAD CONVECTION...OTHER THAN THE SUN HEATING THE GROUND
TODAY. SPRINKLES OR A BRIEF LIGHT SHOWER ARE ALL THE RAIN
EXPECTED...BUT THE GREATER THREATS WITH ANY THUNDERSTORMS WOULD BE
GUSTY WINDS AND LIGHTNING. THE MOISTURE DECREASES SOME ON
FRIDAY...BUT HEATING MIGHT BE MORE EFFECTIVE SO WE WILL CONTINUE THE
SMALL CHANCES MAINLY IN THE MOUNTAINS. ON SATURDAY THE FLOW STARTS
TO COME FROM THE DRIER SOUTHWEST AND SHUTS OFF THE FLOW OF MOISTURE
ALOFT. TEMPERATURES WILL BE VERY SIMILAR THE NEXT FEW DAYS IN ALL
AREAS. NEXT WEEK MODELS ALL SHOW A TROUGH HANGING DOWN ALONG THE
WEST COAST WHICH TRIES TO BUDGE THE BIG RIDGE OVER THE CENTRAL U.S.
IT SHOULD BE ENOUGH TO KEEP THE MONSOON TYPE MOISTURE AWAY AND
DEEPEN OUR MARINE LAYER. THAT WILL BRING SLIGHTLY COOLER WEATHER TO
ALL AREAS AND EXTEND THE COASTAL CLOUDS AND FOG FARTHER INTO THE
VALLEYS EACH NIGHT THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...
020900Z...STRATUS WILL SPREAD 12 MILES INLAND BY DAWN WITH BASE AT
1000 FT MSL AND TOPS 1500 FT. COASTAL MESAS AND HIGHER COASTAL
TERRAIN WILL HAVE 2-3 MILE VIS. THE STRATUS WILL CLEAR BY 16Z BUT
LOCAL STRATUS WILL OCCUR AT THE BEACHES INTO THE AFTERNOON. EXPECT A
SIMILAR MARINE LAYER TONIGHT. SCT TO OCCASIONALLY BKN CONDITIONS
WILL OCCUR AT/ABOVE FL150 TODAY WITH SCATTERED TSTORMS OVER THE MTNS
AND HIGH DESERTS AND ISOLATED OVER THE LOWER DESERTS. BASES WILL
GENERALLY BE AROUND FL090 WITH TOPS TO FL400. LOCAL GUSTY SFC WINDS
TO 40 KNOTS WILL BE POSSIBLE ALONG WITH STRONG UP/DOWNDRAFTS. TSTORM
ACTIVITY SHOULD DIMINISH EARLY EVENING.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MM
AVIATION...MACKECHNIE
000
FXUS66 KHNX 020856
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
156 AM PDT THU JUL 2 2009
.DISCUSSION...EDWARDS RADAR SHOWS AN INCREASE IN THUNDERSTORM
ACTIVITY EAST OF THE AREA OVER SAN BERNARDINO COUNTY EARLY THIS
MORNING AS THE STEADY NORTHWARD STREAM OF MOISTURE IS COMING UNDER
THE INFLUENCE OF THE INCOMING SHORTWAVE TROUGH NOW PUSHING TOWARD
THE CENTRAL COAST. THE BIG QUESTION FOR TODAY OVER THE HANFORD
FORECAST AREA IS HOW FAR WEST AND EXTENSIVE THE THUNDERSTORM
THREAT WILL BE. THE WEATHER SCENARIO APPEARS TO BE THE CLASSIC
BATTLE BETWEEN INCREASING MORE STABLE SOUTHWEST FLOW VERSUS
LINGERING MOISTURE AND INCREASED DYNAMICS. WATER VAPOR IMAGERY IS
ALREADY SHOWING INCREASED LIFT OVER CENTRAL CALIFORNIA AS THE
TROUGH APPROACHES HOWEVER IT APPEARS THE DEEPER MOISTURE IS
LOCATED TO THE EAST OF THE AREA AND WILL LIKELY STAY THAT WAY.
THERE MAY BE A BRIEF PERIOD OF THE MID LEVEL FLOW BACKING TO THE
SOUTH AND POSSIBLY THE SOUTHEAST THIS AFTERNOON AND THIS WOULD
ALLOW FOR THE BEST SHOT AT THUNDERSTORM DEVELOPMENT IN THE SIERRA
AND THE KERN COUNTY MOUNTAINS AND DESERTS. WILL LEAVE THE CURRENT
POPS ALONE AS THEY ARE IN THE SLIGHT CHANCE TO CHANCE CATEGORY. BY
LATER TONIGHT AS THE SHORT WAVE MOVES ONSHORE AND TO THE EAST,
NEARLY ALL OF THE MOISTURE WILL BE SHIFTED TO THE EAST EFFECTIVELY
ENDING ANY THUNDERSTORM THREAT. A DRY SOUTHWEST FLOW IS THEN
PROJECTED TO CONTINUE WELL INTO NEXT WEEK, THUS THE THUNDER THREAT
IS A ONE SHOT DEAL TODAY.
AS FOR TEMPERATURES, LITTLE CHANGE SHOULD OCCUR THROUGH SATURDAY
WITH SOME MINOR COOLING SUNDAY AS HEIGHTS BEGIN TO FALL. BY MONDAY
AND ESPECIALLY TUESDAY FORECAST MODELS BRING IN MUCH LOWER HEIGHTS
AS A LOW PRESSURE CENTER IS PROGGED TO MOVE ACROSS NORTHERN
CALIFORNIA. THE COMBINATION OF LOWER HEIGHTS AND MARINE AIR WILL
CERTAINLY BRING A NOTABLE COOL DOWN WITH LOTS OF 80S OVER THE SAN
JOAQUIN VALLEY AND EVEN INTO THE KERN COUNTY DESERTS.
&&
.AVIATION...ISOLATED THUNDERSTORMS CAN BE EXPECTED OVER THE
SOUTHERN SIERRA NEVADA AND THE KERN COUNTY MOUNTAINS AND DESERT
BETWEEN 19Z TODAY AND 04Z FRIDAY. OTHERWISE...VFR CONDITIONS
WILL PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR THROUGH 12Z
FRIDAY.
&&
.AIR QUALITY ISSUES...
ON THURSDAY JULY 2 2009... UNHEALTHY IN KERN AND TULARE COUNTIES.
UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO... KINGS... MADERA AND
MERCED COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...DUDLEY
AVN/FW...DURFEE
WEATHER.GOV/HANFORD
000
FXUS66 KMTR 020558
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
845 PM PDT WED JUL 1 2009
.DISCUSSION...AS OF 8:45 PM PDT WEDNESDAY...SOMEWHAT COOLER WEATHER
WAS EXPERIENCED TODAY ACROSS THE DISTRICT WITH HIGH TEMPERATURES
RANGING FROM THE 60S AT THE COAST TO THE 70S AND 80S INLAND. THE
WARMEST AREAS SAW READINGS IN THE UPPER 90S...MAINLY ACROSS THE FAR
SOUTHERN INLAND PORTIONS OF MONTEREY COUNTY. SATELLITE IMAGERY SHOWS
COASTAL STRATUS PEELING AWAY FROM THE COAST SOMEWHAT...ALTHOUGH NOT
TOO FAR. MEANWHILE AFTERNOON THUNDERSTORM ACTIVITY OVER THE SIERRA
NEVADA AS WELL AS THE SISKIYOU AND SOUTHERN CASCADES IS STARTING TO
DIMINISH. THE FORT ORD PROFILER INDICATES A MARINE LAYER DEPTH OF
AROUND 1800 FEET...AND THE SURFACE PRESSURE GRADIENT HAS INCREASED
ONSHORE WITH 3.5 MB BETWEEN SFO AND SAC LAST HOUR. THUS...EXPECT
COASTAL LOW CLOUDS TO REGROUP AND SPREAD LOCALLY INLAND ONCE AGAIN
TONIGHT.
THE UPPER LOW THAT IS CURRENTLY LOCATED WEST OF CENTRAL CALIFORNIA
IS FORECAST TO HELP SPREAD SOME MID-LEVEL MOISTURE AND INSTABILITY
NORTHWARD FOR THE POSSIBILITY OF THUNDERSTORMS EDGING INTO THE
SOUTHEASTERN MOUNTAINS OF OUR CWA LATE TOMORROW. THIS INCLUDES THE
HIGHER TERRAIN OF SAN BENITO...SANTA CLARA AND ALAMEDA COUNTIES.
BY FRIDAY THE UPPER LOW IS FORECAST TO MOVE EAST AND THE WIND FLOW
BECOMES MORE WESTERLY THUS SHUTTING OFF THIS MOISTURE SOURCE. A
SERIES OF UPPER TROUGHS IS PROGGED TO MOVE ACROSS THE WEST KEEPING
SEASONABLE TEMPERATURES AND NIGHT NIGHT AND MORNING LOW CLOUDS INTO
NEXT WEEK.
&&
.AVIATION...AS OF 10:30 PM PDT WEDNESDAY...SOUTHERLY FLOW CONTINUES
ALONG THE COAST. THIS BRINGS STRATUS INTO SOUTHERN MRY BAY
EARLY WHILE HOLDING OFF UNTIL LATE TONIGHT IN THE SFO BAY AREA.
VICINITY OF KSFO...STRATUS WILL FILL IN OVER THE BAY LATER
TONIGHT WITH CEILINGS BY 08-09Z. BASES WILL ONCE AGAIN BE IN THE
1000-1400 FEET RANGE THROUGH 17-18Z TOMORROW.
KSFO BRIDGE APPROACH...EXPECT STRATUS AGAIN TONIGHT WITH CEILINGS BY
08-09Z.
MONTEREY BAY TERMINALS...STRATUS WITH BASES STARTING OUT OUT AT
1000-1500 FEET WILL THEN LOWER TO 500-1000 FEET LATER TONIGHT.
CLEARING TO THE BAY BY 18Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: SSA
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS65 KPSR 020554 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1050 PM MST WED JUL 1 2009
.UPDATE...
UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED OVER
SOUTH-CENTRAL ARIZONA THIS EVENING BEFORE TAPERING OFF AFTER
MIDNIGHT. THE DAILY THREAT FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE WORK WEEK...ALONG WITH HIGH
TEMPERATURES A FEW DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. LATE
IN THE WEEKEND AND INTO EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW
WILL CONFINE SHOWERS AND THUNDERSTORMS TO PRIMARILY THE HIGHER
TERRAIN NORTH AND EAST OF THE PHOENIX AREA...WHILE ALLOWING HIGH
TEMPERATURES TO RETURN TO NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
CONVECTION HAS NOT MATERIALIZED OVER MUCH OF THE FORECAST AREA THIS
EVENING BUT ISOLATED STORM ACTIVITY OVER PINAL COUNTY AND OUTFLOWS
ELSEWHERE INCLUDING THE PHOENIX AREA ARE STILL GOING ON AS OF THIS
WRITING. THE UPPER LEVEL DISTURBANCE PROGGED BY THE MODELS DOES NOT
APPEAR TO BE A FACTOR...WOULD HAVE EXPECTED STORM ACTIVITY TO BE
LONGER LIVED AND MORE WIDESPREAD OVER SOUTHERN ARIZONA BY NOW. 00Z
AND 03Z PSR SOUNDING SHOWS A MODEST AMOUNT OF CAPE COUNTERED BY A
FAIR AMOUNT OF CONVECTIVE INHIBITION. A STRONG OUTFLOW ENTERING THE
SOUTHEAST PHOENIX AREA MAY LEAD TO SOME ISOLATED SHORT LIVED STORMS
BUT THAT WOULD BE ABOUT IT. WILL NEED TO MAKE SOME UPDATES TO THE
FORECAST TO REMOVE POPS FROM SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA FOR TONIGHT.
FOR THURSDAY...BOTH NAM AND GFS INDICATE THAT THE DEEPEST MOISTURE
FOR OUR FORECAST AREA WILL BE OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...THOUGH THE GFS IS A BIT MORE GENEROUS WITH THE MOISTURE
OVER SOUTH-CENTRAL ARIZONA. THEY ALSO SHOW SOUTH-SOUTHWEST STEERING
FLOW WHICH IS NOT AN IDEAL DIRECTION FOR LOWER ELEVATION STORM
ACTIVITY. GFS INDICATES ANOTHER PERTURBATION MOVING THROUGH TOMORROW
EVENING...BUT NOT THOSE FEATURES ARE NOT MODELED WELL ENOUGH TO
COUNT ON. IN SHORT NO MAJOR CHANGES FOR TOMORROW IN THE KINEMATICS
BUT THERE SHOULD BE LESS CLOUD COVER SO THERE SHOULD BE MORE SURFACE
HEATING WHICH SHOULD HELP REDUCE SOME OF THE CONVECTIVE INHIBITION.
PREVIOUS DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...THUNDERSTORMS HAVE DIMINISHED
SIGNIFICANTLY AS OF LATE THIS EVENING WITH ISOLATED LIGHT SHOWERS
OVER NORTHERN PINAL COUNTY. OUTFLOW FROM DISTANT THUNDERSTORMS WILL
KEEP AN EASTERLY WIND DIRECTION AT THE TAF SITES THE REST OF THE
NIGHT. STORM PROBABILITY AT THE TAF SITES IS TOO LOW TO INSERT TEMPO
GROUPS FOR THUNDERSTORMS. HOWEVER...INSERTED VCSH IN ACKNOWLEDGEMENT
OF THE PRESENCE OF THE LIGHT SHOWERS. EXPECT THESE TO DISSIPATE
OVERNIGHT WITH JUST SOME LINGERING DEBRIS CLOUDINESS. STORM
POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT LOOK
SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL HELP
REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP.
KIPL/KBLH AND SURROUNDING AIRFIELDS...SOME AREAS OF MID AND HIGH
CLOUDINESS WILL SLOWLY DISSIPATE OVERNIGHT. NO STORM ACTIVITY IS
ANTICIPATED OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA THE REST
OF THE NIGHT BEFORE ISOLATED DEVELOPMENT BEGINS THURSDAY
AFTERNOON...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...AJ
FIRE WEATHER...SIPPLE
000
FXUS66 KLOX 020547
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1050 PM PDT WED JUL 1 2009
.SYNOPSIS...A MOIST MID-LEVEL FLOW PATTERN WILL CONTINUE THROUGH
AT LEAST THURSDAY AS THE UPPER RIDGE REMAINS OVER THE FOUR CORNERS
AREA. THE RIDGE WILL SHIFT EAST THROUGH THE WEEKEND ALLOWING FOR A
DRIER SOUTHWEST FLOW ALOFT TO ESTABLISH. AN APPROACHING TROUGH
SHOULD DIG SOUTH ALONG THE WEST COAST NEXT WEEK...POSSIBLY
INCREASING ONSHORE FLOW AND BRINGING A COOLING TREND.
&&
.UPDATE...MARINE LAYER CLEARED OFF WELL THIS AFTERNOON DUE TO A
WEAK COLD AIR ADVECTIVE PATTERN THAT DEVELOPED OVER THE AREA.
LATEST NAM-WRF AND 13-KM RUC SOLUTIONS STILL INDICATE MARINE
LAYER REDEVELOPING LATE TONIGHT...BUT IT IS LIKELY THAT IT WILL
REMAIN CONFINED AGAIN TO THE COASTAL AREAS. THERE IS LESS
CONFIDENCE OF ARRIVAL OVER THE VENTURA COUNTY COAST AND ALONG
THE SANTA BARBARA SOUTH COAST...BUT WITH THE WEAK TROUGH
APPROACHING IT IS POSSIBLE THAT MARINE LAYER WILL HAVE NOT
PROBLEM REESTABLISHING.
ANOTHER LOW CONFIDENCE FORECAST FOR THUNDERSTORMS IS STARTING
DEVELOP FOR THURSDAY AFTERNOON AND EVENING. THE LATEST NAM-WRF
SOLUTION IS TRENDING THE BEST LOW AND MIDDLE MOISTURE TO THE EAST.
THOUGH THERE ARE SOME MIDDLE-LEVEL CAPE VALUES AND NEGATIVE LIFTED
INDICES...A WARM AIR ADVECTIVE PATTERN CONTINUES TO OCCUR AT 500
MB FOR THURSDAY. WITH THE CAPPING INVERSION IN PLACE OVER THE LAST
SEVERAL DAYS...CONFIDENCE IN CONVECTIVE DEVELOPMENT CONTINUES TO
WANE THIS EVENING. JUDGING BY THE LATEST WATER VAPOR IMAGERY AND
FIRST FEW FRAMES OF THE UKMET MODEL SOLUTIONS...THERE IS SOME
INCLINATION TO REDUCE POPS FOR THURSDAY AFTERNOON AND EVENING.
HOWEVER WITH THE UKMET SOLUTION STILL ARRIVING AND THE GFS MODEL
SOLUTION QUEUED...DATA WILL BE EXAMINED A LITTLE FURTHER BEFORE
REDUCING THE POPS OVER THE AREA.
OTHERWISE...950 MB TEMPERATURES AND SURFACE GRADIENTS INITIALIZED
WELL WITH THE LATEST NAM-WRF MODEL SOLUTION. THE 00Z NAM-WRF MODEL
SOLUTION DOES WARM THE 950 MB TEMPERATURES FOR THURSDAY AND IT IS
POSSIBLE THAT THURSDAY COULD BE WARMER IF THE MOIST FLOW REMAINS
EAST OF THE AREA. WITH THE LATEST SURFACE GRADIENTS REMAINING
NEARLY UNCHANGED FOR THURSDAY FROM TODAY...SOME CONCERNS DOES
EXIST THAT THURSDAY COULD BE SIMILAR TO TODAY OR SLIGHTLY WARMER.
ANY UPDATES WILL WAIT ON THE REST OF THE EVENING MODEL RUNS TO
ARRIVE.
&&
.PREV DISCUSSION... /ISSUED 200 PM PDT WED JUL 1 2009/
SHORT TERM...OTHER THAN PREVIOUSLY MENTIONED CONVECTIVE
CONCERNS...FORECAST IS VERY BLAND. AS THE UPPER RIDGE
FLATTENS...H5 HEIGHTS ACTUALLY RISE SLIGHTLY FRIDAY/SATURDAY.
EFFECTS ON THE AREA WILL BE MINIMAL WITH MINOR FLUCTUATIONS IN THE
MARINE LAYER AND TEMPS THROUGH SATURDAY WITH MOST AREAS AROUND
SEASONAL NORMS.
LONG TERM...OVERALL...EXTENDED MODELS HAVE THE SAME
IDEA...ALTHOUGH THEY DIFFER IN THE DETAILS. AT UPPER LEVELS...
FLAT RIDGE WILL REMAIN ON SUNDAY...THEN AN UPPER LOW WILL DROP
SOUTHEAST ACROSS THE WEST COAST MONDAY THROUGH WEDNESDAY. THE GFS
IS NOTICEABLY DEEPER WITH THE UPPER LOW TUESDAY AND WEDNESDAY THAN
THE ECMWF. NEAR THE SURFACE...ONSHORE FLOW WILL CONTINUE TO
STRENGTHEN.
FORECAST-WISE...EXPECT A COOLING TREND THROUGH THE PERIOD WITH
AN INCREASE IN THE MARINE INFLUENCE. WILL INDICATE A GRADUAL
COOLING TREND THROUGH THE PERIOD...TOWING A MIDDLE GROUND BETWEEN
THE GFS AND ECMWF. MOST AREAS WILL BE A FEW DEGREES BELOW SEASONAL
NORMS MONDAY THROUGH WEDNESDAY. WITH THIS PATTERN...UPPER-LEVEL
FLOW WILL BE SOUTHWESTERLY WHICH WILL KEEP ANY MONSOONAL MOISTURE
WELL EAST OF THE AREA.
&&
.AVIATION...
02/0550Z.
MARINE LAYER WILL MOVE IN TO ALL COASTAL SITES LATER THIS MORNING.
THE CENTRAL COAST WILL FILL IN FIRST AND THE SITES SOUTH OF POINT
CONCEPTION WILL FILL IN SLOWLY AFTER MIDNIGHT. CLEARING WILL LIKELY
TAKE PLACE BETWEEN 16Z AND 18Z. AFTER 21Z ON THURSDAY...THERE IS A
SLIGHT CHANCE THAT THUNDERSTORMS DEVELOP NEAR KPMD AND KWJF.
KLAX...LOW CLOUDS WILL ARRIVE WITHIN TWO HOURS OF FCST TIME
TONIGHT/THU MORNING. BURN OFF COULD BE AN HOUR EARLIER THAN FCST.
KBUR...VERY GOOD CONFIDENCE IN TAF.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HALL/SETO
PUBLIC...HALL/THOMPSON
AVIATION...ASR
WWW.WEATHER.GOV/LOSANGELES
000
FXUS65 KPSR 020452
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
950 PM MST WED JUL 1 2009
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED OVER
SOUTH-CENTRAL ARIZONA THIS EVENING BEFORE TAPERING OFF AFTER
MIDNIGHT. THE DAILY THREAT FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE WORK WEEK...ALONG WITH HIGH
TEMPERATURES A FEW DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. LATE
IN THE WEEKEND AND INTO EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW
WILL CONFINE SHOWERS AND THUNDERSTORMS TO PRIMARILY THE HIGHER
TERRAIN NORTH AND EAST OF THE PHOENIX AREA...WHILE ALLOWING HIGH
TEMPERATURES TO RETURN TO NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
CONVECTION HAS NOT MATERIALIZED OVER MUCH OF THE FORECAST AREA THIS
EVENING BUT ISOLATED STORM ACTIVITY OVER PINAL COUNTY AND OUTFLOWS
ELSEWHERE INCLUDING THE PHOENIX AREA ARE STILL GOING ON AS OF THIS
WRITING. THE UPPER LEVEL DISTURBANCE PROGGED BY THE MODELS DOES NOT
APPEAR TO BE A FACTOR...WOULD HAVE EXPECTED STORM ACTIVITY TO BE
LONGER LIVED AND MORE WIDESPREAD OVER SOUTHERN ARIZONA BY NOW. 00Z
AND 03Z PSR SOUNDING SHOWS A MODEST AMOUNT OF CAPE COUNTERED BY A
FAIR AMOUNT OF CONVECTIVE INHIBITION. A STRONG OUTFLOW ENTERING THE
SOUTHEAST PHOENIX AREA MAY LEAD TO SOME ISOLATED SHORT LIVED STORMS
BUT THAT WOULD BE ABOUT IT. WILL NEED TO MAKE SOME UPDATES TO THE
FORECAST TO REMOVE POPS FROM SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA FOR TONIGHT.
FOR THURSDAY...BOTH NAM AND GFS INDICATE THAT THE DEEPEST MOISTURE
FOR OUR FORECAST AREA WILL BE OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...THOUGH THE GFS IS A BIT MORE GENEROUS WITH THE MOISTURE
OVER SOUTH-CENTRAL ARIZONA. THEY ALSO SHOW SOUTH-SOUTHWEST STEERING
FLOW WHICH IS NOT AN IDEAL DIRECTION FOR LOWER ELEVATION STORM
ACTIVITY. GFS INDICATES ANOTHER PERTURBATION MOVING THROUGH TOMORROW
EVENING...BUT NOT THOSE FEATURES ARE NOT MODELED WELL ENOUGH TO
COUNT ON. IN SHORT NO MAJOR CHANGES FOR TOMORROW IN THE KINEMATICS
BUT THERE SHOULD BE LESS CLOUD COVER SO THERE SHOULD BE MORE SURFACE
HEATING WHICH SHOULD HELP REDUCE SOME OF THE CONVECTIVE INHIBITION.
PREVIOUS DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...CLOUDINESS FROM EARLIER TODAY
HAS THINNED OUT. THIS SHOULD AID IN THE DEVELOPMENT OF INSTABILITY
BUT STORMS HAVE BEEN SLOW TO DEVELOP ON THE LOWER ELEVATIONS. WILL
BE WATCHING STORM ACTIVITY OVER SOUTHEAST ARIZONA AND THE RIM
COUNTRY TO PRODUCE OUTFLOWS WHICH MAY PROVIDE NECESSARY LIFT TO
TRIGGER STORMS OVER THE PHOENIX AREA. WITHOUT THAT...WILL NEED
DYNAMICAL HELP FROM A DISTURBANCE PROGGED TO MOVE NORTHWARD ACROSS
ARIZONA TONIGHT. THIS DISTURBANCE IS NOT READILY EVIDENT IN THE
WATER VAPOR IMAGERY THOUGH. HOWEVER...LOCATION OF MOST ACTIVE
CONVECTION IN SOUTHEAST ARIZONA CORRESPONDS WELL WITH WHERE THIS
FEATURE SHOULD BE. DUE TO THE MEAGER LATE AFTERNOON CONVECTIVE
ACTIVITY...HAVE HELD OFF ON PUTTING IN TEMPO GROUPS FOR
THUNDERSTORMS AND STRONG WINDS IN THE TAFS. BUT POTENTIAL IS STILL
THERE SO AMMENDMENTS WILL QUITE POSSIBLY BE NECESSARY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...DEBRIS CLOUDINESS HAS
CONTINUED TO HOLD ON FROM NEAR THE LOWER COLORADO RIVER VALLEY
WESTWARD. THIS HAS LIKELY INHIBITED INSTABILITY. WITH HIGH DEW
POINTS...AND MODEST AIR TEMPERATURES...ANY STORMS THAT DO DEVELP
WILL BE MORE LIKELY TO PRODUCE BRIEF HEAVY RAIN THAN VERY STRONG
WINDS. CLOUD BASES WOULD LIKELY BE WELL BELOW 10 KFT. DUE TO THE
ABUNDANT MOISTURE...STORM ACTIVITY CANT BE RULED OUT...BUT THIS AREA
SEEMS LESS LIKELY TO BENEFIT FROM THE UPPER DISTURBANCE ADVERTISED
TO MOVE THROUGH ARIZONA. THUS HAVE HELD OFF ON TEMPO GROUPS FOR
THUNDERSTORMS. BUT DUE TO MOISTURE AVAILABILITY...STORM POTENTIAL IS
STILL THERE SO AMMENDMENTS MAY VERY WELL BE NECESSARY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...AJ
FIRE WEATHER...SIPPLE
000
FXUS66 KSTO 020433
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 PM PDT WED JUL 01 2009
.DISCUSSION...
MUCH OF THE THUNDERSTORM ACTIVITY ON WED SKIRTED OUR FORECAST AREA
WITH OUR SHASTA CO MTNS/LASSEN PARK AREA IN THE NOMINAL PROXIMITY OF
NRN MTN CONVECTION NEAR THE CA/OR BORDER. THE CONVECTION WAS FOCUSED
THERE DUE TO SEVERAL FEATURES...A VORT MAX ROTATING NEWD AROUND THE
OFFSHORE LOW AND OVER THE NRN MTNS...UPPER LEVEL DIVERGENCE ALONG A
DEFORMATION ZONE...AND IN THE DIFFLUENT ZONE OF THE OFFSHORE UPPER
LOW. 24H MAX TEMP CHANGES INDICATED 2 MAIN AREAS OF COOLING...ONE IN
THE DELTA INFLUENCED AREAS DUE TO A 1700-2000 FOOT MARINE LAYER AND
ONSHORE GRADIENTS...AND THE OTHER OVER WRN PLUMAS CO AND THE SHASTA
CO MTNS DUE TO SYNOPTIC COOLING.
CONVECTION LOOKS MINIMAL/PROBLEMATIC IN OUR FORECAST AREA ON THU AS
THE OFFSHORE LOW IS FORECAST TO FILL ALONG WITH WEAKENING
DIVERGENCE/DIFFLUENCE AND DEFORMATION ZONE. THE EFFECT OF A VORT MAX
IS ALSO PROBLEMATIC AS WATER VAPOR IMAGERY SHOWS A VORT MAX ROUNDING
THE BASE OF THE OFFSHORE TROF AND LIFTING NEWD TOWARDS THE CENTRAL
CA COAST. THE MODELS HAVE THIS FEATURE MOVING SLOWLY TOWARD THE
COAST AND INLAND BUT GENERALLY AFTER MAX HEATING. THE FILLING UPPER
SYSTEM THO IS WHAT IS KEEPING A LOW/TENUOUS POP IN THE MTNS THU/FRI
FOR NOW. DUE TO THE FILLING OFFSHORE SYSTEM...THERE IS ALSO EXPECTED
TO BE A SLIGHTLY WEAKER ONSHORE BREEZE AND DELTA INFLUENCE IN THE
INTERIOR AREAS WHERE MAX TEMPS SHOULD MODIFY SLIGHTLY. THE DELTA
INFLUENCE IS NOT SUFFICIENTLY STRONG ENOUGH THIS EVENING FOR
INTRUSION OF STRATUS INTO THE SRN SAC VLY AS THE STRATUS SCHEME CAME
OUT NEGATIVE FOR THE INTERIOR VLY FOR THU MORNING. JHM
.PREVIOUS DISCUSSION...
NAM GENERATING CONVECTIVE ACTIVITY OVER THE HIGHER TERRAIN FRIDAY AS
UPPER LOW NEARS KACV AND PWS INCREASE TO .75 INCHES OVER THE SIERRA
AND NORTHEAST PLATEAU TO OVER AN INCH IN THE COASTAL MOUNTAINS AND
WESTERN MOUNTAINS OF SHASTA COUNTY. AMS ALSO COOLS SOME SYNOPTICALLY
WITH 850 MB TEMPS DROPPING ABOUT 2 TO 3 DEG C TO AROUND 22-23 DEG C.
AS A RESULT...MAX TEMPS FRIDAY FOR THE CENTRAL VALLEY EXPECTED TO BE
MAINLY IN THE 90S.
UPPER LOW WEAKENS TO TROUGH AND MOVES THROUGH THE NORTH FRIDAY NIGHT
INTO SATURDAY MORNING. DRIER SOUTHWESTERLY FLOW ALOFT DEVELOPS OVER
NORCAL SATURDAY AS TEMPS REBOUND SLIGHTLY. ANOTHER LOW PRESSURE
SYSTEM BEGINS TO MOVE INTO THE EPAC SATURDAY BUT ECMWF/GFS DIFFER ON
STRENGTH OF THIS LOW AND HAVE ALSO BEEN INCONSISTENT FROM RUN TO
RUN. LARGE SPREAD IN ENSEMBLE SOLUTIONS TOO OVER THE HOLIDAY WEEKEND
EQUATING TO DIFFERING HEIGHTS OVER NORCAL. MAIN THEME FROM MODELS
THOUGH IS MOVING FEATURE TOWARDS THE PACNW COAST SUNDAY WHICH
SUGGESTS INCREASED ONSHORE FLOW WITH SOME COOLING FOR INTERIOR
NORCAL. ADDITIONAL COOLING THROUGH EARLY NEXT WEEK AS LONG WAVE
TROUGH BECOMES ESTABLISHED ALONG THE WEST COAST. MOS GUIDANCE
SUGGESTING MAX TEMPS AROUND 5 TO 10 DEGREES BELOW NORMAL WITH VALLEY
HIGHS IN THE 80S WITH PLEASANT 60S TO 70S IN THE HIGHER TERRAIN.
PCH
.EXTENDED DISCUSSION (SUNDAY THRU WEDNESDAY)...
A SLOW MOVING TROUGH WILL MOVE ACROSS NORCAL EXTENDING THE COOLING
TREND INTO MID WEEK THAT WILL DROP VALLEY HIGH TEMPS INTO THE 80S
AND KEEP THEM THERE FOR A FEW DAYS. JUST HOW COOL... FOR HOW
LONG... AND HOW FAR SOUTH WILL DEPEND UPON HOW STRONG THE TROUGH
BECOMES AND WHETHER IT LIFTS UP THROUGH OREGON. CURRENT FORECAST
ALLOWS THE TROUGH TO LIFT SOMEWHAT NORTH BUT NOT ENTIRELY. SURFACE
WINDS WILL KICK UP IN THE FAVORED MOUNTAIN AREAS AS THE TROUGH MOVES
THROUGH THE AREA BUT NOTHING SIGNIFICANT IS EXPECTED AT THIS TIME
PRIMARILY DUE TO THE MARGINAL STRENGTH AND POSITIONING OF THE
SYSTEM. DELTA FLOW WILL CONTINUE THROUGH THE PERIOD AS WELL BUT AS
WILL STAY RELATIVELY TAME. KJ
&&
.AVIATION...
VFR MAINLY SKC CONDITIONS IN INTERIOR NORCAL EXCEPT FOR ISOLATED TO
SCATTERED THUNDERSTORMS AND POSSIBLE MVFR/IFR CIGS OVER MTNS FROM
19Z THU TO 04Z FRI. ONSHORE/DELTA BREEZE EXPECTED TO WEAKEN JUST
SLIGHTLY ON THU AS OFFSHORE LOW FILLS OR WEAKENS. THIS WILL PRECLUDE
STRATUS INTRUSION INTO THE SRN SAC VLY TONITE...BUT STRATUS AND IFR
CONDITIONS EXPECTED TO DEVELOP IN THE INTERIOR COASTAL VLYS AND INTO
THE CARQUINEZ STRAIT OVERNITE AND LASTING TO 15Z-18Z THU. MARINE
LAYER 1700-2000 FT MSL.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS66 KHNX 020430
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
930 PM PDT WED JUL 1 2009
.DISCUSSION...SKIES CLEARING AGAIN THIS EVENING ACROSS THE EASTERN
SIDE OF THE DISTRICT AFTER TODAYS CONVECTION. WITH A CONTINUED
SLIGHTLY WESTERLY DIRECTION OF THE SOUTHERLY WIND FLOW
ALOFT...MOST OF THIS EVENINGS CLOUD COVER MOVED INTO THE GREAT
BASIN. OTHER THEN A FEW HIGH CLOUDS ROLLING OVER THE AREA
OVERNIGHT...WILL NOT EXPECT ANY ADDITIONAL WEATHER CONCERNS UNTIL
WELL AFTER DAYBREAK ON THURSDAY. WITH LITTLE CHANGE IN THE NEXT
24 HOURS...WILL SEE AN ADDITIONAL DAY OF VERY WARM TEMPERATURES.
WHILE FEWER LOCATIONS WILL SEE TRIPLE DIGITS TEMPERATURES...MOST
LOCATIONS WERE REACH JUST BELOW THE 100 DEG-F MARK...EVEN WITH
SOME CLOUDS AFTER FROM THURSDAY CONVECTIVE ACTIVITY. SHORT RANGE
MODELS SHOW THE FLOW ALOFT BECOMING SLIGHTLY MORE SOUTHEASTERLY AS
MORE MOISTURE SURGES UP FROM THE SOUTH. A WEAK CLOSED LOW OFF THE
PACIFIC COAST WILL ALLOW THE FLOW ALOFT TO SHIFT MORE EASTERLY AND
ADVECT MOISTURE INTO THE DISTRICT. THEREFORE...WILL CONTINUE TO
MENTION A SLIGHT CHANCE OF THUNDERSTORMS FOR THE MOUNTAINS AS
INSTABILITY AND MOISTURE WILL ALLOW FOR SOME POTENTIAL DURING
THURSDAY AFTERNOON. WILL MAKE NO UPDATES TO THE CURRENT FORECAST.
&&
.AVIATION...MVFR WITH ISOLATED IFR IN ISOLATED TO SCATTERED
THUNDERSTORMS CAN BE EXPECTED OVER THE SOUTHERN SIERRA NEVADA AND
THE KERN COUNTY MOUNTAINS AND DESERT FOR MUCH OF THE DAY THURSDAY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE REMAINDER OF THE
CENTRAL CALIFORNIA INTERIOR THROUGH 06Z FRIDAY.
&&
.AIR QUALITY ISSUES...ON THURSDAY JULY 2 2009...
UNHEALTHY IN KERN AND TULARE COUNTIES. UNHEALTHY FOR SENSITIVE
GROUPS IN FRESNO...KINGS...MADERA AND MERCED COUNTIES. FURTHER
INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...JDB
WEATHER.GOV/HANFORD
000
FXUS65 KREV 020428
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
928 PM PDT WED JUL 1 2009
.UPDATE...
CONVECTION HAS DECREASED SIGNIFICANTLY WITH LOSS OF BOTH DAYTIME
HEATING AND ENHANCED LIFT ASSOCIATED WITH LEFT EXIT REGION OF JET
STREAK NOW MOVING INTO SOUTHERN OREGON. ISOLATED THUNDERSTORMS
CONTINUE OVER MINERAL...SOUTHERN MONO...AND SOUTHERN CHURCHILL
COUNTIES BUT THESE HAVE BEEN DECREASING AND THE 00Z NAM AND LATEST
SREF PRODUCTS SUGGEST NO SHOWERS/THUNDERSTORMS AFTER MIDNIGHT.
HAVE UPDATED ALL FORECASTS TO REFLECT THE LATEST RADAR AND
SATELLITE TRENDS. NO CHANGES MADE TO FORECAST FOR THU AND BEYOND
AT THIS TIME. RC
&&
.PREVIOUS DISCUSSION... /ISSUED 242 PM PDT WED JUL 1 2009/
SHORT TERM...
SOME ISOLATED THUNDERSTORMS HAVE ALREADY BEGUN THIS AFTERNOON ACROSS
THE FAR NORTHERN AND FAR SOUTHERN AREAS OF THE FORECAST AREA. JET
STREAK IS PUSHING DIRECTLY OVER THE FORECAST AREA THIS
AFTERNOON...WITH THE DIFLUENT LEFT EXIT REGION OF THE JET OVER
LASSEN COUNTY-SURPRISE VALLEY-NORTHERN WASHOE COUNTY. WE SHOULD SEE
CONVECTION CONTINUE TO INCREASE IN COVERAGE AND INTENSITY THROUGH
THE REST OF THE AFTERNOON AND INTO THE EVENING...WITH STORMS
GENERALLY SLOW MOVING AND PUTTING DOWN SOME MODERATE RAINFALL.
FARTHER SOUTH...STORMS HAVE BEEN MORE ISOLATED IN COVERAGE SO
FAR...BUT GENERALLY STRONGER. BETTER OVERALL SHEAR ALOFT DOWN IN
MONO-MINERAL COUNTIES WITH THE JET OVERHEAD. EXPECT STORMS TO
CONTINUE THROUGH THE EVENING HOURS...TAPERING OFF AFTER WE LOSE
DAYTIME HEATING.
FOR TOMORROW...EXPECT ANOTHER ROUND OF ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE AREA. CONTINUED MOISTURE ADVECTION INTO THE
AREA WILL HELP MAKE IT EVEN EASIER FOR THUNDERSTORMS TO POP
THURSDAY. ALSO WITH THE INCREASED MOISTURE...STORMS WILL BECOME
WETTER AS WELL...NOT HAVING TO BREAK THROUGH AS DEEP OF A DRY LOW
LAYER. PW VALUES OF NEAR 0.75 INCH WILL GET PULLED UP INTO
MONO-MINERAL COUNTIES FROM THE UPPER LOW OFF THE NORTHERN CA COAST.
WE WILL HAVE PLENTY OF INSTABILITY FROM DAYTIME HEATING...ALTHOUGH A
BIT MARGINAL WITH ZERO TO -1 LIFTED INDEX VALUES ACROSS MOST OF THE
FORECAST AREA. THUNDERSTORMS ARE EXPECTED TO BE MORE ISOLATED IN THE
RENO-TAHOE AREA...WITH WEAK CAPPING ALOFT. STORMS MAY NEED TO BE
REMOVED ALTOGETHER IF THE CAP IS STRONGER THAN EXPECTED. BETTER
COVERAGE EXPECTED NORTH-SOUTH-EAST OF RENO-TAHOE. HOON
THE WEAK LOW OFF THE CA COAST IS EXPECTED TO GRADUALLY SWING THROUGH
NRN CA/NV FRIDAY INTO SATURDAY AND AID IN DEVELOPING SHOWERS AND
THUNDERSTORMS. ALTHOUGH INSTABILITY IS MARGINAL FRIDAY...FORCING AND
MOISTURE IN PLACE SHOULD BE SUFFICIENT FOR MOST OF THE FORECAST AREA
TO AT LEAST HAVE A CHANCE OF CONVECTIVE DEVELOPMENT. THERE SHOULD BE
SOME RAIN WITH THE CORES OF STORMS DUE TO PW`S OF 0.65-0.8".
ALTHOUGH...STORM SPEED WILL BE RELATIVELY FAST DUE TO 3-8KM LAYER
WINDS OF 20-30KTS. MODELS DIFFER ON WHAT IS TO TRANSPIRE SATURDAY
WITH THE NAM KEEPING MOISTURE IN PLACE AND DEVELOPING CONVECTION DUE
TO SLOWER EJECTION OF THE NRN CA LOW. THE GFS BRINGS IN DRIER AND
MORE STABLE WESTERLY FLOW BY SATURDAY WHICH LOOKS MORE REASONABLE AT
THIS TIME AND IS WHAT THE GOING FORECAST IS BASED OFF. MILNE
LONG TERM...SUNDAY THROUGH WEDNESDAY...
SLIGHTLY ABOVE NORMAL TEMPS ARE EXPECTED AS THE HOLIDAY WEEKEND
COMES TO A CLOSE...THEN A TREND TOWARD COOLER TEMPS IS EXPECTED THRU
THE MIDDLE OF NEXT WEEK AS LONGWAVE TROF APPROACHES THE WEST COAST
WHILE THE RIDGE AXIS SHIFTS EAST TO THE CENTRAL US. MAX TEMPS COULD
BE 10-15 DEGREES BELOW NORMAL BY NEXT WED...WHICH WOULD RESULT IN
MAINLY LOWER 80S FOR MOST VALLEYS...IF THIS SYSTEM MAINTAINS THE
TRACK AND INTENSITY INDICATED BY MOST GUIDANCE. THE MAIN DISCREPANCY
IS WHETHER MORE COOLING WILL BE NOTICED ON MONDAY OR TUESDAY. THE
ECMWF IS SLOWER WHILE GFS IS FASTER...WITH ENSEMBLES VARYING BETWEEN
THESE TWO SCENARIOS. THEREFORE THE FORECAST WILL SPLIT THE
DIFFERENCE AND FAVOR A MORE STEADY COOLING TREND EARLY NEXT WEEK.
PRECIP POTENTIAL STILL LOOKS SPARSE WITH THIS SYSTEM. THE PROJECTED
LOCATION OF THE TROF/UPPER LOW WOULD KEEP A DRY AND STABLE AIR MASS
ACROSS NEARLY ALL OF ERN CA AND WRN NV. THE ONLY POSSIBLE EXCEPTION
WOULD BE IN EXTREME NERN CA AND NWRN NV NEAR THE OREGON BORDER WHERE
LIFT ASSOCIATED WITH THE LOW MAY TRIGGER A FEW SHOWERS TUES-WED.
BREEZY WEST WINDS WILL PREVAIL EACH AFTERNOON AND EVENING WITH GUSTS
OF 30-35 MPH POSSIBLE...A BIT STRONGER THAN THE TYPICAL ZEPHYR. MJD
AVIATION...
VFR CONDS TO PREVAIL THRU THURS AT THE TAF SITES WITH SCT-BKN CU-TCU
AND ISOLD CB BTWN 20Z-03Z EACH DAY. ISOLD-SCT HIGH-BASED -TSRA
POSSIBLE 21Z-03Z TODAY AND THURS MAINLY SOUTH OF KTVL AND NORTH OF
SUSANVILLE-GERLACH LINE. GUSTY OUTFLOW WINDS TO 35 KTS POSSIBLE NEAR
STORMS...OTHERWISE LEE SIDE ZEPHYR BREEZES VCNTY KRNO TODAY AND
THURS WITH GUSTS 20-25 KT BTWN 22Z-03Z. MJD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
HTTP://WEATHER.GOV/RENO
000
FXUS66 KSGX 020418
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
915 PM PDT WED JUL 1 2009
.SYNOPSIS...MID LEVEL MOISTURE IN SOUTHEAST FLOW ALOFT WILL BRING A
SLIGHT CHANCE OF MAINLY AFTERNOON AND EARLY EVENING THUNDERSTORMS IN
AND NEAR THE MOUNTAINS THROUGH FRIDAY. DRIER SOUTHWEST WINDS ALOFT
WILL GRADUALLY LOWER THE HUMIDITIES THROUGH THE HOLIDAY WEEKEND.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
THE STEADY STREAM OF MID LEVEL MONSOON MOISTURE HAS INCREASED THE
PRECIPITABLE WATER TO 1.60 INCHES ON THE 00Z NKX SOUNDING. THE PW`S
PEAK TONIGHT AND THURSDAY AS MOISTURE INCREASES IN THE SFC-700 MB
LAYER. THAT SHOULD RESULT IN BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS THAN WE HAVE HAD THE PAST TWO DAYS. ALSO...THE
CONVECTIVE COMPLEX OVER SONORA MEXICO IS STRONGER AND LARGER THAN
LAST NIGHT AND AN EASTERLY WAVE OR OUTFLOW BOUNDARY FROM THE
CONVECTIVE COMPLEX MAY REACH SOUTHERN CA TOMORROW. IF THAT WERE TO
HAPPEN...OUR CHANCES FOR THUNDERSTORMS WOULD BE EVEN HIGHER.
LASTLY...SURFACE DEWPOINTS HAVE SURGED NICELY OVER THE PAST 12 HOURS
AND ARE NOW IN THE 50S IN THE SAN DIEGO AND RIVERSIDE COUNTY MTNS
AND DESERTS...AND INTO THE 40S IN THE SAN BERNARDINO COUNTY MTNS AND
DESERTS. LOOKS LIKE ANOTHER WARM...HUMID DAY THURSDAY WITH
TEMPERATURES HIGHLY DEPENDENT ON CLOUD COVER. TODAY THE CLOUD COVER
LIMITED SOLAR HEATING AND HELD TEMPS IN THE 90S IN THE
DESERTS...ABOUT 10 DEGREES BELOW AVERAGE.
ON FRIDAY THE 4-CORNERS HIGH BEGINS TO WEAKEN AND SHIFT EAST IN
RESPONSE TO AN ADVANCING EASTERN PACIFIC TROUGH. REMNANT MOISTURE
AND DAYTIME HTG FRIDAY COULD TRIGGER A MTN OR DESERT T-STORM FRIDAY.
HUMIDITIES WILL START TO FALL OFF SATURDAY AND CONTINUE TO DROP OFF
SUNDAY WITH PREVAILING SOUTHWEST WINDS ALOFT ACCOMPANYING THE WEAK
TROUGH. EXPECT SLIGHTLY COOLER WEATHER WEST OF THE MTNS FROM A
DEEPER MARINE LAYER THROUGH EARLY NEXT WEEK. BUT THE LOWER MOISTURE
CONTENT AND INCREASED SUN WILL PUSH TEMPS BACK OVER THE CENTURY MARK
IN THE DESERTS.
&&
.AVIATION...
020340Z...STRATUS HAD DEVELOPED ALONG THE SAN DIEGO COUNTY COAST AND
WILL SPREAD UP TO ABOUT 12 MILES INLAND OVERNIGHT. KCRQ HAD ALREADY
GONE BROKEN...AND KSAN SHOULD GO BROKEN AROUND 05Z. CIGS WILL
AVERAGE AROUND 1000 FT MSL WITH TOPS ONLY A FEW HUNDRED FEET HIGHER.
STRATUS WILL EVENTUALLY REACH COASTAL ORANGE COUNTY...MOSTLY BETWEEN
06Z AND 09Z. A FEW LOCATIONS...MAINLY ON THE COASTAL MESAS AND
HIGHER COASTAL TERRAIN COULD HAVE 2-3 MILE VIS OVERNIGHT. THE
STRATUS WILL CLEAR MOST AREAS AROUND 16Z THU...BUT LOCAL STRATUS
WILL OCCUR AT THE BEACHES INTO THE AFTERNOON.
INLAND...GENERALLY SCT TO OCCASIONALLY BKN CONDITIONS WILL OCCUR
AT/ABOVE FL150 OVERNIGHT. AN ISOLATED TSTORM IS POSSIBLE OVER THE
MTNS/DESERTS...MAINLY AFTER 08Z BUT CHANCE OF A TSTORM OCCURRING
NEAR KPSP OR KTRM IS LOW OVERNIGHT. TSTORM CHANCES WILL INCREASE
AFTER 17Z THU AND ARE EXPECTED TO BE SCATTERED OVER THE MTNS/HIGH
DESERTS AND ISOLATED OVER THE LOWER DESERTS. BASES WILL GENERALLY BE
AROUND FL090 WITH TOPS TO FL400. LOCAL GUSTY SFC WINDS TO 40 KNOTS
WILL BE POSSIBLE ALONG WITH STRONG UP/DOWNDRAFTS. TSTORM ACTIVITY
SHOULD DIMINISH EARLY THU EVENING.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOEDE
AVIATION...MAXWELL
000
FXUS66 KMTR 020346
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
845 PM PDT WED JUL 1 2009
.DISCUSSION...AS OF 8:45 PM PDT WEDNESDAY...SOMEWHAT COOLER WEATHER
WAS EXPERIENCED TODAY ACROSS THE DISTRICT WITH HIGH TEMPERATURES
RANGING FROM THE 60S AT THE COAST TO THE 70S AND 80S INLAND. THE
WARMEST AREAS SAW READINGS IN THE UPPER 90S...MAINLY ACROSS THE FAR
SOUTHERN INLAND PORTIONS OF MONTEREY COUNTY. SATELLITE IMAGERY SHOWS
COASTAL STRATUS PEELING AWAY FROM THE COAST SOMEWHAT...ALTHOUGH NOT
TOO FAR. MEANWHILE AFTERNOON THUNDERSTORM ACTIVITY OVER THE SIERRA
NEVADA AS WELL AS THE SISKIYOU AND SOUTHERN CASCADES IS STARTING TO
DIMINISH. THE FORT ORD PROFILER INDICATES A MARINE LAYER DEPTH OF
AROUND 1800 FEET...AND THE SURFACE PRESSURE GRADIENT HAS INCREASED
ONSHORE WITH 3.5 MB BETWEEN SFO AND SAC LAST HOUR. THUS...EXPECT
COASTAL LOW CLOUDS TO REGROUP AND SPREAD LOCALLY INLAND ONCE AGAIN
TONIGHT.
THE UPPER LOW THAT IS CURRENTLY LOCATED WEST OF CENTRAL CALIFORNIA
IS FORECAST TO HELP SPREAD SOME MID-LEVEL MOISTURE AND INSTABILITY
NORTHWARD FOR THE POSSIBILITY OF THUNDERSTORMS EDGING INTO THE
SOUTHEASTERN MOUNTAINS OF OUR CWA LATE TOMORROW. THIS INCLUDES THE
HIGHER TERRAIN OF SAN BENITO...SANTA CLARA AND ALAMEDA COUNTIES.
BY FRIDAY THE UPPER LOW IS FORECAST TO MOVE EAST AND THE WIND FLOW
BECOMES MORE WESTERLY THUS SHUTTING OFF THIS MOISTURE SOURCE. A
SERIES OF UPPER TROUGHS IS PROGGED TO MOVE ACROSS THE WEST KEEPING
SEASONABLE TEMPERATURES AND NIGHT NIGHT AND MORNING LOW CLOUDS INTO
NEXT WEEK.
&&
.AVIATION...AS OF 4:30 PM PDT WEDNESDAY...SOUTHERLY FLOW CONTINUES
ALONG THE COAST. THIS WILL BRING STRATUS INTO SOUTHERN MRY BAY
EARLY WHILE HOLDING OFF UNTIL LATE TONIGHT IN THE SFO BAY AREA.
VICINITY OF KSFO...VFR CONDITIONS THROUGH THE AIRPORT EVENING
RUSH HOUR. STRATUS WILL FILL IN OVER THE BAY LATE TONIGHT WITH
CEILINGS BY 08-09Z. BASES WILL ONCE AGAIN BE IN THE 1000-1400 FEET
RANGE THROUGH 17-18Z TOMORROW.
KSFO BRIDGE APPROACH...CONDITIONS WILL BE VFR THROUGH THE AIRPORT
EVENING RUSH HOUR. EXPECT STRATUS AGAIN TONIGHT WITH CEILINGS
BY 08-09Z.
MONTEREY BAY TERMINALS...SOUTHEAST FLOW ALOFT HAS EVAPORATED THE
CLOUDS FROM THE COAST. THIS WILL KEEP STRATUS FROM GETTING INTO SNS
AND MRY UNTIL AFTER 04Z. BASES WILL START OUT OUT AT 1000-1500 FEET
THEN LOWER TO 500-1000 FEET.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY.
&&
$$
PUBLIC FORECAST: SSA
AVIATION/MARINE: W PI
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
000
FXUS66 KLOX 020340
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
840 PM PDT WED JUL 1 2009
.SYNOPSIS...A MOIST MID-LEVEL FLOW PATTERN WILL CONTINUE THROUGH
AT LEAST THURSDAY AS THE UPPER RIDGE REMAINS OVER THE FOUR CORNERS
AREA. THE RIDGE WILL SHIFT EAST THROUGH THE WEEKEND ALLOWING FOR A
DRIER SOUTHWEST FLOW ALOFT TO ESTABLISH. AN APPROACHING TROUGH
SHOULD DIG SOUTH ALONG THE WEST COAST NEXT WEEK...POSSIBLY
INCREASING ONSHORE FLOW AND BRINGING A COOLING TREND.
&&
.UPDATE...MARINE LAYER CLEARED OFF WELL THIS AFTERNOON DUE TO A
WEAK COLD AIR ADVECTIVE PATTERN THAT DEVELOPED OVER THE AREA.
LATEST NAM-WRF AND 13-KM RUC SOLUTIONS STILL INDICATE MARINE
LAYER REDEVELOPING LATE TONIGHT...BUT IT IS LIKELY THAT IT WILL
REMAIN CONFINED AGAIN TO THE COASTAL AREAS. THERE IS LESS
CONFIDENCE OF ARRIVAL OVER THE VENTURA COUNTY COAST AND ALONG
THE SANTA BARBARA SOUTH COAST...BUT WITH THE WEAK TROUGH
APPROACHING IT IS POSSIBLE THAT MARINE LAYER WILL HAVE NOT
PROBLEM REESTABLISHING.
ANOTHER LOW CONFIDENCE FORECAST FOR THUNDERSTORMS IS STARTING
DEVELOP FOR THURSDAY AFTERNOON AND EVENING. THE LATEST NAM-WRF
SOLUTION IS TRENDING THE BEST LOW AND MIDDLE MOISTURE TO THE EAST.
THOUGH THERE ARE SOME MIDDLE-LEVEL CAPE VALUES AND NEGATIVE LIFTED
INDICES...A WARM AIR ADVECTIVE PATTERN CONTINUES TO OCCUR AT 500
MB FOR THURSDAY. WITH THE CAPPING INVERSION IN PLACE OVER THE LAST
SEVERAL DAYS...CONFIDENCE IN CONVECTIVE DEVELOPMENT CONTINUES TO
WANE THIS EVENING. JUDGING BY THE LATEST WATER VAPOR IMAGERY AND
FIRST FEW FRAMES OF THE UKMET MODEL SOLUTIONS...THERE IS SOME
INCLINATION TO REDUCE POPS FOR THURSDAY AFTERNOON AND EVENING.
HOWEVER WITH THE UKMET SOLUTION STILL ARRIVING AND THE GFS MODEL
SOLUTION QUEUED...DATA WILL BE EXAMINED A LITTLE FURTHER BEFORE
REDUCING THE POPS OVER THE AREA.
OTHERWISE...950 MB TEMPERATURES AND SURFACE GRADIENTS INITIALIZED
WELL WITH THE LATEST NAM-WRF MODEL SOLUTION. THE 00Z NAM-WRF MODEL
SOLUTION DOES WARM THE 950 MB TEMPERATURES FOR THURSDAY AND IT IS
POSSIBLE THAT THURSDAY COULD BE WARMER IF THE MOIST FLOW REMAINS
EAST OF THE AREA. WITH THE LATEST SURFACE GRADIENTS REMAINING
NEARLY UNCHANGED FOR THURSDAY FROM TODAY...SOME CONCERNS DOES
EXIST THAT THURSDAY COULD BE SIMILAR TO TODAY OR SLIGHTLY WARMER.
ANY UPDATES WILL WAIT ON THE REST OF THE EVENING MODEL RUNS TO
ARRIVE.
&&
.PREV DISCUSSION... /ISSUED 200 PM PDT WED JUL 1 2009/
SHORT TERM...OTHER THAN PREVIOUSLY MENTIONED CONVECTIVE
CONCERNS...FORECAST IS VERY BLAND. AS THE UPPER RIDGE
FLATTENS...H5 HEIGHTS ACTUALLY RISE SLIGHTLY FRIDAY/SATURDAY.
EFFECTS ON THE AREA WILL BE MINIMAL WITH MINOR FLUCTUATIONS IN THE
MARINE LAYER AND TEMPS THROUGH SATURDAY WITH MOST AREAS AROUND
SEASONAL NORMS.
LONG TERM...OVERALL...EXTENDED MODELS HAVE THE SAME
IDEA...ALTHOUGH THEY DIFFER IN THE DETAILS. AT UPPER LEVELS...
FLAT RIDGE WILL REMAIN ON SUNDAY...THEN AN UPPER LOW WILL DROP
SOUTHEAST ACROSS THE WEST COAST MONDAY THROUGH WEDNESDAY. THE GFS
IS NOTICEABLY DEEPER WITH THE UPPER LOW TUESDAY AND WEDNESDAY THAN
THE ECMWF. NEAR THE SURFACE...ONSHORE FLOW WILL CONTINUE TO
STRENGTHEN.
FORECAST-WISE...EXPECT A COOLING TREND THROUGH THE PERIOD WITH
AN INCREASE IN THE MARINE INFLUENCE. WILL INDICATE A GRADUAL
COOLING TREND THROUGH THE PERIOD...TOWING A MIDDLE GROUND BETWEEN
THE GFS AND ECMWF. MOST AREAS WILL BE A FEW DEGREES BELOW SEASONAL
NORMS MONDAY THROUGH WEDNESDAY. WITH THIS PATTERN...UPPER-LEVEL
FLOW WILL BE SOUTHWESTERLY WHICH WILL KEEP ANY MONSOONAL MOISTURE
WELL EAST OF THE AREA.
&&
.AVIATION...01/0340Z.
VFR CONDITIONS WILL LIKELY PERSIST THROUGHOUT THE PERIOD OVER THE
INLAND TERMINALS. HOWEVER...LIFR TO IFR CONDITIONS WILL LIKELY
DEVELOP OVER THE COASTAL TERMINALS AFTER 06Z TONIGHT...WITH THE
LATER TIME POSSIBLY OCCURRING SOUTH OF POINT CONCEPTION. AT
COASTAL TERMINALS...VFR CONDITIONS SHOULD REDEVELOP OVER THE AREA
AROUND 17Z. AFTER 19Z ON THURSDAY...THERE IS A SLIGHT CHANCE THAT
THUNDERSTORMS DEVELOP NEAR KPMD AND KWJF.
KLAX...LOW CONFIDENCE EXISTS IN ARRIVAL TIME OF MARINE LAYER. VFR
CONDITIONS WILL PERSIST AT LEAST THROUGH 07Z THIS EVENING...THEN
IFR CONDITIONS WILL BECOME PREDOMINANT OVER KLAX AND VICINITY. VFR
CONDITIONS SHOULD REDEVELOP AROUND 17Z THURSDAY.
KBUR...VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGHOUT THE
PERIOD.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HALL/SETO
PUBLIC...HALL/THOMPSON
AVIATION...HALL
WWW.WEATHER.GOV/LOSANGELES
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