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000
FXUS66 KLOX 170315 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED NATIONAL
WEATHER SERVICE LOS ANGELES/OXNARD CA
815 PM PDT THU MAY 16 2013

.SYNOPSIS...
OVERNIGHT LOW CLOUDS AND FOG...POSSIBLE MORNING DRIZZLE...AND
ONSHORE BREEZES WILL KEEP DAYTIME TEMPERATURES BELOW NORMAL ON
FRIDAY. A WARMING TREND WILL BEGIN SATURDAY AND PEAK ON MONDAY WITH
A BUILDING RIDGE OF HIGH PRESSURE AND SOME WEAK OFFSHORE FLOW.

&&

.SHORT TERM (TODAY-SUN)...A WEAK AND DRY TROUGH MOVED THROUGH THE
REGION TODAY. A BAND OF MID AND HIGH CLOUDINESS ASSOCIATED WITH THE
TROUGH SHOULD MOVE EAST OF THE REGION BY MIDNIGHT. ANOTHER AREA OF
HIGH CLOUDINESS WILL LIKELY MOVE INTO AT LEAST SOUTHERN PORTIONS OF
THE FORECAST AREA TONIGHT. THE QUESTION FOR TONIGHT IS HOW MUCH OF A
LOW CLOUD FIELD WILL DEVELOP IN THE WAKE OF THE SYSTEM...GIVEN THE
AMOUNT OF HIGH CLOUDINESS AND THE FACT THAT MARINE INVERSION HAS
WEAKENED QUITE A BIT. LOW CLOUDS HAVE ALREADY BEGUN TO REDEVELOP ON
THE CENTRAL COAST...AND SOME STRATUS HAS BEGUN TO DEVELOP ACROSS
ORANGE COUNTY AND SRN SECTIONS OF L.A. COUNTY. SO...THE CURRENT
FORECAST SHOWING ABUNDANT LOW CLOUDS IN COASTAL AND VALLEY AREAS
LOOKS TO BE ON TRACK. SOME LOCAL DRIZZLE IS POSSIBLE...ESPECIALLY
ACROSS L.A. COUNTY GIVEN THE STRENGTH OF THE ONSHORE FLOW AND THE
DEEP MARINE LAYER (OVER 3000 FEET DEEP).

GUSTY WINDS CONTD ACROSS THE ANTELOPE VALLEY...AND A WIND ADVISORY
REMAINS IN EFFECT THERE THROUGH LATE THIS EVENING. SOME GUSTY WINDS
HAVE ALSO DEVELOPED THROUGH AND BELOW PASSES AND CANYONS OF SOUTHERN
SBA COUNTY...ENOUGH TO JUSTIFY A LOW LEVEL WIND ADVISORY THROUGH
LATE TONIGHT. N-S GRADIENTS SHOULD KEEP LOW CLOUDS OUT OF SOUTHERN
SBA COUNTY THROUGH AT LEAST VERY LATE TONIGHT.


...FROM PREVIOUS DISCUSSION...

ANOTHER COOLER THAN NORMAL DAY FRIDAY WITH BREEZY CONDITIONS FOR THE
COAST, MOUNTAINS, AND ANTELOPE VALLEY. WINDS EXPECTED TO REMAIN
BELOW ADVISORY LEVELS IN MOST AREAS EXCEPT POSSIBLY THE AV. THE HIGH
CLOUDS FROM THE TROF EXPECTED TO PASS THROUGH BY MORNING SO EITHER
MOSTLY SUNNY OR PARTLY CLOUDY MOST AREAS BY AFTERNOON.

A WARMING TREND EXPECTED TO BEGIN SATURDAY, MAINLY FOR INLAND AREAS.
STILL A FAIRLY WEAK INVERSION FOR SOUTHERN AREAS SO NOT A REAL SOLID
MARINE LYR EXPECTED. RIDGE STARTS BUILDING OVER THE AREA LATE
SATURDAY INTO SUNDAY FOR MORE SIGNIFICANT WARMING FOR INLAND AREAS
AND LESS SO FOR THE COAST AS ONSHORE FLOW PERSISTS. THE BUILDING OF
THE RIDGE WITH TROFFING TO OUR EAST WILL PUT THE SQUEEZE ON THE
WINDS SATURDAY NIGHT INTO EARLY SUNDAY AND WE COULD SEE SOME
ADVISORY LEVEL NORTHWEST WINDS OVER THE GRAPEVINE AND SRN SBA COUNTY
DURING THAT TIME.

.LONG TERM (MON-THU)...WARMEST DAY OF THE PERIOD EXPECTED TO BE
MONDAY UNDER WEAK OFFSHORE FLOW. DOESN`T LOOK QUITE AS WARM AS IT
DID A COUPLE DAYS AGO BUT STILL 90S IN THE VALLEYS AND 70S TO LOWER
80S FOR COASTAL AREAS. JUST A BRIEF WARMUP THOUGH AS THE NEXT TROF
BRINGS COOLER TEMPS AND BREEZY ONSHORE FLOW TO THE AREA THROUGH THE
REMAINDER OF NEXT WEEK, ESPECIALLY BY THU AND FRI.

&&

.AVIATION...16/2340Z...
FAIRLY LOW CONFIDENCE IN 00Z TAF FORECAST AS IT IS UNCERTAIN EXACTLY
HOW MUCH STRATUS WILL REDEVELOP TONIGHT. THE INVERSION IS QUITE WEAK
BEHIND THE FRONTAL PASSAGE. AT THIS POINT...WILL CONTINUE THE IDEA
WITH STRATUS RE-FORMING AND AFFECTING MOST COASTAL AND VALLEY AREAS
LATE TONIGHT/FRI MORNING...WITH CONDS MAINLY MVFR.


KLAX...LOW TO MODERATE CONFIDENCE IN 00Z TAFS. THERE IS A 30% CHANCE
THAT CONDS WILL REMAIN VFR THROUGH THE PERIOD.


KBUR...LOW TO MODERATE CONFIDENCE IN 00Z TAFS. THERE IS A 30% CHANCE
THAT CONDS WILL REMAIN VFR THROUGH THE PERIOD.
&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...MW/DB
AVIATION...SMITH
SYNOPSIS...SETO

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