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000
FXUS66 KLOX 110513
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
913 PM PST TUE DEC 10 2013

.SYNOPSIS...

OFFSHORE FLOW WILL KEEP A DRY AIR MASS IN PLACE THROUGH
FRIDAY...WITH CONTINUED COLD NIGHTS AND CHILLY DAYS. A WEAK LOW
PRESSURE SYSTEM WILL MOVE IN FRIDAY TO COOL TEMPERATURES A FEW
DEGREES. AN UPPER-LEVEL HIGH AND OFFSHORE FLOW WILL CREATE A
WARMING TREND FROM SATURDAY TO THE MIDDLE OF NEXT WEEK.

&&

.UPDATE...

OFFSHORE FLOW CONTINUES TO WANE ACROSS THE AREA THIS EVENING AS
THE WIND ALOFT DIMINISH AND PRESSURE GRADIENTS WEAKEN. WITH THE
WIND DIMINISHING ACROSS THE AREA...LESS MIXING OCCURRING...AND
CLEAR SKIES...RADIATIONAL COOLING PROCESSES SHOULD BE EFFICIENT
TONIGHT ACROSS THE CENTRAL COAST...SANTA BARBARA SOUTH
COAST...VENTURA COUNTY VALLEYS...AND SAN FERNANDO AND SANTA
CLARITA VALLEYS. A FROST ADVISORY WAS EXPANDED INTO SOME VALLEY
AREAS. THE COLDEST TEMPERATURES IN THE VALLEYS WILL LIKELY OCCUR
IN WIND-SHELTERED LOCATIONS SUCH AS OJAI...WOODLAND
HILLS...CALABASAS...AND FILLMORE. WITH THE ANTELOPE AND INTERIOR
VALLEYS ALREADY HAVING TWO FREEZE EVENTS PRIOR TO TONIGHT...NO
ADDITIONAL WARMING WILL BE ISSUED FOR THE SEASON.

A GRADUAL WARMING TREND SHOULD OCCUR ON WEDNESDAY AND POSSIBLY
INTO THURSDAY AS OFFSHORE FLOW DIMINISH AND THE AIR MASS
STAGNATES SOME.

&&

.PREV DISCUSSION...

SHORT TERM...QUIET PERIOD OF WEATHER NEXT SEVERAL DAYS WITH NO
PRECIP EXPECTED THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
LINGERING OFFSHORE FLOW WILL GENERATE SUB-ADVISORY LEVEL NORTHEAST
WINDS ACROSS THE AREA THROUGH THURSDAY BEFORE GRADIENTS BRIEFLY
TURN WEAKLY ONSHORE FRIDAY AS A WEAK TROF PASSES THROUGH THE WEST
COAST. DAYTIME HIGHS WILL WARM A COUPLE DEGREES EACH DAY BEFORE
LEVELING OFF OR EVEN COOLING A COUPLE DEGREES FRIDAY WITH THE
ONSHORE TRENDS AND TROF PASSAGE. THE ECMWF SOLUTION IS COOLER WITH
THE TROF EVOLVING INTO A SEMI CUTOFF UPPER LOW JUST WEST OF THE
COASTLINE THU AND FRI. BUT STILL DRY SO THE ONLY POTENTIAL IMPACT
TO THE FORECAST WOULD BE COOLER HIGHS FRI THAN WHAT WE HAVE GOING
CURRENTLY. OVERNIGHT TEMPS WILL REMAIN CHILLY, ESPECIALLY IN WIND
PROTECTED LOCATIONS.

LONG TERM (SAT-TUE)...A WARMING TREND THROUGH EARLY NEXT WEEK AS
HIGH PRESSURE BUILDS ALOFT AND WEAK OFFSHORE FLOW RETURNS. COULD BE
LOOKING AT HIGHS NEAR OR JUST ABOVE 80 BY SUN AND/OR MON FOR VALLEYS
AND MID TO UPPER 70S FOR SOUTHERN COASTAL AREAS.

&&

.AVIATION...11/0214Z.

VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD. THERE IS A SLIGHT
CHANCE OF MODERATE LOW-LEVEL WIND SHEAR AT TERMINALS SOUTH OF POINT
CONCEPTION.

KLAX...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD. ANY EAST
WINDS WILL REMAIN LESS THAN 5 KNOTS.

KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD. NO WIND
ISSUES ARE EXPECTED AT THIS TIME.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL/MW
AVIATION...HALL
SYNOPSIS...SETO/HALL

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