000
FXUS66 KLOX 192046
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
145 PM PDT FRI SEP 19 2008

.SHORT TERM (TODAY-MON)...TROF MOVING INTO NRN CA THIS AFTERNOON
WITH A WEAK FRONTAL BOUNDARY EXTENDING SOUTH JUST OFF THE CENTRAL
COAST. THE TROF WILL MOVE INLAND OVERNIGHT, SETTING UP A DECENT
SUNDOWNER ACROSS SRN SBA COUNTY. AT THIS TIME IT LOOKS LIKE WINDS
WILL STAY BELOW ADVISORY LEVELS BUT THERE COULD BE SOME ISOLATED
GUSTS APPROACHING 40 MPH THROUGH SOME OF THE CANYONS. NORTHERLY FLOW
WILL LIKELY KEEP SRN SBA COUNTY CLEAR OVERNIGHT, HOWEVER CLOUDS
SHOULD SPREAD ONSHORE ALONG THE CENTRAL COAST SOMETIME THIS EVENING
OR OVERNIGHT AND POSSIBLY INTO LA AND VENTURA COUNTIES LATE TONIGHT.
CONFIDENCE IN THE LATTER IS LOW AS THE LOW CLOUDS HAVE BEEN PUSHING
SOUTH WELL INTO BAJA THIS AFTERNOON. HOWEVER, THE 18Z NAM IS NOW
SHOWING A LITTLE EDDY CIRCULATION CENTERED OFF LA COUNTY WHICH COULD
HELP CLOUDS TO FORM AND SPREAD NORTHWARD OVERNIGHT.

MODELS SHOW SIZABLE COOLING AT 950MB SAT ALONG WITH LOW CLOUDS
MAKING IT INTO THE VALLEYS LATE TONIGHT. THE EDDY DOESN`T SEEM
STRONG ENOUGH TO LIFT THE MARINE LYR ENOUGH TO SPREAD THE CLOUDS IN
THE VALLEYS, BUT IF THEY DO FORECAST HIGHS ON SAT MAY BE A COUPLE
DEGREES TOO WARM.

LOW CLOUDS SHOULD HAVE A BETTER CHANCE OF MAKING IT INLAND ON SUNDAY
AS THE EDDY STRENGTHENS AND THIS SHOULD LEAD TO A COUPLE MORE
DEGREES OF COOLING. CLOUDS SHOULD ALSO SPREAD UP TO AT LEAST VENTURA
COUNTY AND POSSIBLY PORTIONS OF SRN SBA COUNTY AS WELL, THOUGH
MODELS STILL SHOW DECENT NORTHERLY FLOW OVER SRN SBA COUNTY THROUGH
EARLY SUNDAY MORNING.

MOS GUIDANCE NOW SHOWS A SLIGHT WARMING TREND FOR MOST AREAS ON
MONDAY AS THICKNESSES AND 950 TEMPS RISE. HOWEVER, THIS SEEMS A BIT
ODD GIVEN THAT 500 MB HEIGHTS LOWER SLIGHTLY, ONSHORE FLOW IS A TAD
STRONGER, AND THE EDDY IS STILL THERE. DECIDED TO SPLIT THE
DIFFERENCE AND GO WITH SIMILAR TEMPS MON AS SUN WITH JUST A DEGREE
OR TWO OF WARMING WELL INLAND.

.LONG TERM (TUE-FRI)...WARMING TREND STILL ON TRACK FOR THE MIDDLE
OF NEXT WEEK. GFS HAS BACKED OFF SLIGHTLY ON THE OFFSHORE FLOW FOR
WED AND THU BUT GRADIENTS SHOULD AT LEAST BE NEAR NEUTRAL IF NOT
SLIGHTLY OFFSHORE. STILL THINK THE GFS IS UNDERDOING THE WARMING AT
950 AS WELL THE MOS GUIDANCE HIGHS. GIVEN THE STRENGTH OF THE UPPER
HIGH AND NEAR NEUTRAL OR SLIGHTLY OFFSHORE SURFACE GRADIENTS, HIGHS
SHOULD BE CLOSE TO 100 IN THE VALLEYS AND CLOSE TO 90 ACROSS THE
INLAND COASTAL PLAIN. FOR THIS REASON CURRENT FORECAST CONTINUES TO
BE WARMER THAN MOS GUIDANCE. WARMING TREND SHOULD END FRI AS ANOTHER
TROF APPROACHES THE COAST AND HIGH PRESSURE MOVES EAST.

&&

.AVIATION...19/1915Z.
A VERY LOW CONFIDENCE FORECAST FOR THE COASTAL TAFS. A TROUGH ALONG
THE WEST COAST WILL DRAG A WEAK FRONT WITH SOME LOW CLOUDS INTO THE
COASTAL WATERS LATER TODAY AND TONIGHT. COASTAL TAFS WITH THE
GREATEST VULNERABILITY TO LOW CLOUDS AND FOG MAY EXPERIENCE PATCHY
LOW CLOUDS AND FOG TONIGHT. THE TIMING OF THE LOW CLOUDS WILL BE
VERY DIFFICULT TO PINPOINT...BUT WILL PROBABLY OCCUR EARLY THIS
EVENING ON THE CENTRAL COAST AND LATER OR NOT AT ALL SOUTH OF POINT
CONCEPTION. VALLEY TAFS ARE EXPECTED TO BE CLEAR THROUGH SATURDAY.

KLAX...A 40 PERCENT CHANCE OF LOW CLOUDS AND FOG WITH MVFR
CONDITIONS AFTER MIDNIGHT...OTHERWISE MOSTLY CLEAR.

KBUR...HIGH CONFIDENCE IN CLEAR SKIES THROUGH SATURDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...WOFFORD
AVIATION...SWEET

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