Southwestern California Discussion
000
FXUS66 KLOX 110559 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1000 PM PST WED MAR 10 2010
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE AREA ON THURSDAY AND FRIDAY
BRINGING MOSTLY CLEAR SKIES AND WARMER TEMPERATURES. A WEAK LOW
PRESSURE AREA COULD BRING A CHANCE OF RAIN BY FRIDAY NIGHT...BUT
MAINLY NORTH OF POINT CONCEPTION. A WARMING TREND WILL DEVELOP FOR
EARLY NEXT WEEK AS AN OFFSHORE FLOW PATTERN WILL LIKELY DEVELOP.
&&
.UPDATE...
LATEST WATER VAPOR IMAGERY INDICATES THE TROUGH AXIS MOVING EAST
OF THE AREA AS A TROUGH CONTINUES TO EXIT THE REGION. SURFACE
GRADIENTS ARE BEGINNING TO RELAX TONIGHT AS THE NORTHERLY GRADIENT
IN PLACE OVER THE LAST COUPLE OF DAYS SUBSIDES. THE LATEST NAM-
WRF SOLUTIONS FOLLOW THIS TREND NICELY WITH WINDS WITHIN THE
BOUNDARY LAYER...AT 975 MB...AND AT 850 MB DIMINISHING THROUGH
LATE TONIGHT. HIGH WIND WARNINGS WILL BE REPLACED BY WIND
ADVISORIES WITH WINDS DIMINISHING...AND GALE WARNINGS WILL BE
REPLACED BY SMALL CRAFT ADVISORIES. A FEW WIND ADVISORIES FOR SOME
AREAS WILL REMAIN IN TACT FOR NOW.
WITH THE WINDS DIMINISHING...A CHILLY NIGHT IS DEVELOPING FOR THE
INTERIOR AND FOR SOME VALLEY LOCATIONS. PATCHY FROST WILL LIKELY
DEVELOP FOR MOST INTERIOR PORTIONS OF THE AREA...WITH SOME LOCALLY
HEAVIER FROST POSSIBLE IN THE OJAI VALLEY AND SOME OF THE
EXTREMELY WIND SHELTERED AREAS.
A WEAK OFFSHORE FLOW PATTERN DEVELOPING OVERNIGHT WILL WARM THE
AIR MASS SUBSTANTIALLY ON THURSDAY. TEMPERATURES SEEM AGREEABLE
BASED UPON THE CURRENT MODEL DATA...BUT SOME CONCERN EXISTS THAT
THURSDAY COULD BE A BIT WARMER IF THE FLOW PATTERN TRENDS MORE
OFFSHORE THROUGHOUT THE DAY. WITH THE SURFACE LOW TRENDING FURTHER
OFFSHORE THIS EVENING THAN WHAT THE MODELS INDICATE...THE PACKAGE
WILL BE BUMPED UP SLIGHTLY TO ALLOW FOR SLIGHTLY BETTER WARMING
OVER THE LOS ANGELES AND VENTURA COUNTY AREAS. AN UPDATE WILL BE
OUT SHORTLY.
&&
.PREV DISCUSSION...
SHORT TERM...FRI STILL LOOKS ABOUT NORMAL TEMPERATURE-WISE...BUT
NOT AS WARM AS THE ADVANCING SYSTEM IS MOVING A BIT QUICKER WITH A
LITTLE MORE PUNCH TO IT THAN PREVIOUSLY EXPECTED. A SMALL RIPPLE
IN THE MAIN LOW CURRENTLY JUST SOUTH OF ALASKA WILL SWING AROUND
THE PARENT LOW AND AMPLIFY ON FRIDAY. THE NEW TROUGH THAT FORMS
WILL PRODUCE A FRONTAL BAND THAT WILL SWEEP DOWN THE COAST. THIS
BAND NOW LOOKS TO HAVE A DECENT ENOUGH JET TO IT TO HOLD TOGETHER
AND AFFECT MAINLY SLO AND NRN SBA COUNTIES FRIDAY NIGHT...WITH
AROUND A TENTH OF AN INCH EXPECTED. UPPED POPS ACCORDINGLY TO HIGH
CHANCE...WITH NRN SLO CO HAVING THE BEST SHOT AT MODERATE
RAIN...LOCALLY UP TO 0.25-0.33 INCHES OVER THE SANTA LUCIAS. NOT
EXPECTING ANY PRECIP OVER LA OR VTU COUNTIES...BESIDES SOME NORTH
SLOPES SNOW/RAIN...BUT CANNOT RULE OUT A SPIT OR TWO OF RAIN COME
SATURDAY. ABOUT A 5 DEGREE COOL DOWN IS IN STORE ON SAT AS A
RESULT...AND GUSTY NORTHWESTERLY WINDS LOOK TO RETURN BEHIND THE
FRONT. THESE WINDS CONTINUE TO STRENGTHEN...AND THE SANTA YNEZ
RANGE AND I-5 CORRIDOR LOOK POISED FOR AT LEAST AN ADVISORY AT
THIS POINT BY SAT NIGHT.
LONG TERM...THE GUSTY NORTHERLY WINDS BEHIND FRIDAY NIGHTS SYSTEM
WILL SHIFT TO THE NORTHEAST BY SUNDAY. ALONG WITH A STILL
IMPRESSIVE LOOKING RIDGE BUILDING FROM THE
SOUTHWEST...TEMPERATURES WILL REBOUND NICELY TO JUST ABOVE NORMAL.
BREEZY NORTHEAST WINDS SHOULD BE EXPECTED AS WELL...AS A MODERATE
OFFSHORE GRAD TAKES SHAPE. MONDAY AND TUESDAY LOOK EVEN
WARMER...AS THE OFFSHORE GRADS INCREASE FURTHER...AND MODELS
CONTINUE TO SHOW A 580+DM RIDGE PUSHING INTO SRN CA. THERE
CONTINUES TO BE GOOD MODEL AND ENSEMBLE AGREEMENT WITH THIS
PATTERN...AND CONFIDENCE IS GROWING FOR 80S IN MOST COASTAL AND
VALLEY SECTIONS. AFTER TUESDAY...THE AGREEMENT BREAKS DOWN AS GFS
KEEPS A RIDGE GOING WHILE THE ECMWF DROPS AND INSIDE SLIDER DOWN
WED NIGHT. THE GFS SOLUTION APPEARS MORE STABLE BASED ON THE
ENSEMBLES...AND LEANED MORE ON THIS SOLUTION WITH ONLY A MODEST
AMOUNT OF COOLING ON WED.
&&
.AVIATION...11/00600Z.
OVERALL...VFR CONDS ARE EXPECTED THROUGH THE TAF PERIOD. THERE WILL
BE SOME AREAS OF LLWS AND MODERATE TURBULENCE ACROSS THE AREA DUE TO
THE NORTH TO NORTHEAST FLOW ALOFT. KBUR...KVNY...KSBA WILL BE MOST
SUSCEPTIBLE TO LLWS AND TURBULENCE.
KLAX...HIGH CONFIDENCE IN 06Z TAF. THERE IS A CHANCE THE NORTHERLY
CROSS WINDS COULD LINGER A COUPLE HOURS BEYOND 10Z.
KBUR...HIGH CONFIDENCE IN 06Z TAF. THERE IS A CHANCE THE NORTHERLY
SURFACE WINDS COULD CONTINUE A COUPLE HOURS AFTER 09Z. AREAS OF LLWS
AND TURBULENCE WILL CONTINUE NEAR THE AIRFIELD DUE TO THE NORTH TO
NORTHEAST FLOW ALOFT.
***NOTE***
THE ASOS EQUIPMENT AT KBUR...KVNY...KHHR...KCMA...AND KOXR HAS A
SOFTWARE ERROR THAT MAY LEAD TO INCORRECT CLOUD HEIGHTS WHEN THERE
ARE TWO OR MORE CLOUD LAYERS PRESENT. OBSERVATIONS AT KBUR WILL BE
QUALITY CONTROLLED 24 HOURS A DAY...OBSERVATIONS AT KVNY WILL BE
QUALITY CONTROLLED FROM 13Z-07Z...OBSERVATIONS AT KOXR WILL BE
QUALITY CONTROLLED FROM 15Z-05Z. TAFS FOR KVNY AND KOXR WILL NOT BE
AMENDED FOR CIGS DURING THE TIME THE OBSERVATIONS ARE NOT MONITORED
AND THERE ARE TWO OR MORE CLOUD LAYERS PRESENT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
COASTAL FLOOD STATEMENT (SEE LAXCFWLOX).
&&
$$
PUBLIC...HALL/KITTELL
AVIATION...RAT
SYNOPSIS...SETO/HALL
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NWS LOX Office Area Forecast Discussion
