FXUS66 KLOX 112203
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PST FRI DEC 11 2009

.SYNOPSIS...

RAIN WITH HIGH ELEVATION SNOW WILL CONTINUE ACROSS THE AREA TONIGHT. 
ANOTHER MORE POTENT STORM SYSTEM WILL MOVE INTO THE AREA SATURDAY
AFTERNOON...BRINGING SIGNIFICANT RAIN AND HIGH ELEVATION SNOW TO
THE AREA THROUGH SUNDAY MORNING. DRY AND WARMING CONDITIONS ARE
EXPECTED NEXT WEEK.

&&

.SHORT TERM (TODAY-MON)...OVERALL...FORECAST THINKING THROUGH THE
SHORT TERM PERIOD IS LOOKING GOOD. FOCUS TODAY HAS BEEN ON AREA
OF RAIN AND ISOLATED THUNDERSTORMS MOVING ACROSS THE AREA. THIS
SYSTEM SHOULD MAINTAIN ITSELF RATHER WELL THROUGH THE EVENING...
BRINGING A SHOT OF RAIN TO THE AREA. AT THIS TIME...THE
BEST SHOT OF RAIN FOR SLO/SBA COUNTIES WILL BE THIS AFTERNOON
AND EARLY EVENING...THEN LATER THIS EVENING AND TONIGHT FOR
VTU/LAX COUNTIES. PER QPF PROGS...BELIEVE THIS SYSTEM WILL BE
VERY SIMILAR TO LAST NIGHT'S WITH REGARD TO PRECIP TOTALS.
SO WILL BE EXPECTING GENERALLY 0.25" TO 0.75" OF RAINFALL THROUGH
SATURDAY MORNING...WITH LOCALLY HIGHER AMOUNTS IN UPSLOPE AREAS.
SNOW LEVELS WILL REMAIN ABOVE 6000 FEET...SO MOST MOUNTAINS AREA
WILL SEE RAIN INSTEAD OF SNOW. WILL LIKELY BE A COUPLE INCHES OF
SNOWFALL AT THE RESORTS OVERNIGHT...BUT NOTHING WARRANTING ANY
WINTER PRODUCTS AT THIS TIME.

AS THIS IMPULSE MOVES OUT SATURDAY MORNING...THERE WILL BE A 
RELATIVE LULL IN THE ACTIVITY THROUGH MOST OF THE DAY ON SATURDAY
WITH SCATTERED SHOWERS ACROSS THE AREA. FOR AREAS NORTH OF POINT
CONCEPTION...STEADY RAIN WILL BECOME LIKELY SATURDAY AFTERNOON
AS THE SECOND SYSTEM MOVES IN.

WITH REGARD TO THE SECOND SYSTEM...IT STILL LOOKS LIKE A VERY GOOD
RAIN PRODUCER FOR THE AREA. MODELS INDICATE SOME RATHER STRONG
SOUTHERLY FLOW LATE SATURDAY AFTERNOON AND EVENING WHICH WILL
BRING IN SOME SUBTROPICAL MOISTURE. SO...WITH SUCH SOUTHERLY FLOW
OROGRAPHIC ENHANCEMENT SHOULD BE PRETTY GOOD. AT THIS TIME...
CURRENT 0.75"-1.50" FOR COASTAL/VALLEY AREAS AND 1.50"-3.00" IN
THE FOOTHILLS AND MOUNTAINS LOOK FINE FOR RAIN TOTALS. WITH
SUCH AMOUNTS AND POTENTIALLY MODERATE RAINFALL RATES EXPECTED...
THERE WILL BE SOME CONCERN ABOUT MUD/DEBRIS FLOWS IN THE BURN
AREAS (ESPECIALLY THE STATION BURN) AND FLASH FLOOD WATCHES WILL
LIKELY BE ISSUED BY LATER SHIFTS. AS FOR SNOW LEVELS...THE SOUTHERLY 
FLOW WILL KEEP SNOW LEVELS ABOVE 6000 FEET THROUGH THE BULK OF
THE RAIN SATURDAY EVENING...BUT SNOW LEVELS WILL DROP EARLY SUNDAY
MORNING AS THE SYSTEM PUSHES THROUGH. WILL EXPECT THE RESORT AREAS
TO GET SOME SIGNIFICANT SNOWFALL. WITH SOUTHERLY WINDS EXPECTED TO
BE RATHER STRONG...DANGEROUS WINTER STORM CONDITIONS WILL BE 
POSSIBLE SATURDAY EVENING THROUGH SUNDAY MORNING. WILL ISSUE A
WINTER STORM WATCH FOR THE VTU/LAX COUNTY MOUNTAINS WITH THE 
AFTERNOON FORECAST PACKAGE.

THROUGH THE DAY SUNDAY...PRECIP WILL TAPER OFF...WITH A DRY
DAY EXPECTED ON MONDAY.

.LONG TERM (TUE-FRI)...OVERALL...12Z MODELS IN GOOD AGREEMENT WITH
THE EXTENDED FORECAST. AT UPPER LEVELS...FLAT RIDGE WILL DEVELOP
ON TUESDAY/WEDNESDAY THEN STRENGTHEN ON THURSDAY/FRIDAY. NEAR THE
SURFACE...VARYING DEGREES OF OFFSHORE FLOW SHOULD PERSIST.

FORECAST WISE...THE ABOVE PATTERN WILL RESULT IN DRY CONDITIONS
AND A WARMING TREND THROUGH THE PERIOD. WITH A MORE ZONAL FLOW
ON TUESDAY/WEDNESDAY...SOME MID/HIGH CLOUDS WILL LIKELY DRIFT 
BY AND PRODUCE PARTLY CLOUDY CONDITIONS. THE OFFSHORE GRADIENTS
WILL ALSO PRODUCE SOME NORTHEAST CANYON WINDS DURING THE PERIOD.

&&

.AVIATION...11/1835Z.
A FAIRLY LOW CONFIDENCE FORECAST FOR TODAY. MAY NEED TO ADD SOME 
SHOWERS TO THE TAFS SOUTH OF POINT CONCEPTION THIS AFTERNOON AS AN 
AREA OF DISTURBED WEATHER ATTEMPTS TO HOLD TOGETHER. THE SHOWERS AND 
POSSIBLY AN ISOLATED THUNDERSTORM WILL FIRST AFFECT KSBA AND KOXR 
WITHIN THE NEXT HOUR AND THEN AFFECT KLAX AND KLGB AS WELL AS KBUR 
AND KVNY WITHIN TWO TO THREE HOURS. THE RAIN THREAT WILL CONTINUE 
THROUGH THE EVENING FOLLOWED BY A BREAK IN THE ACTION OVERNIGHT.

KLAX AND KBUR...MVFR CONDITIONS WITH CLOUDY SKIES...THEN SOME 
DETERIORATION THIS AFTERNOON WITH SOME IFR PERIODS ASSOCIATED WITH 
AN AREA OF SHOWERS. THE SHOWERS CONTINUE THROUGH THE EVENING 
FOLLOWED BY AN IMPROVEMENT OVERNIGHT INTO SATURDAY MORNING. 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).

&&

$$

PUBLIC...THOMPSON
AVIATION...SWEET
SYNOPSIS...

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