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000
FXUS66 KLOX 220001
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
500 PM PDT TUE MAY 21 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A COOLING TREND THAT BEGAN FOR MOST AREAS TODAY WILL CONTINUE
THROUGH THE WEEKEND ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING
LOW CLOUDS AND FOG. BREEZY CONDITIONS ARE EXPECTED ALONG THE CENTRAL
COAST...SOUTHERN SANTA BARBARA COUNTY...INTERSTATE 5 CORRIDOR...AND
THE ANTELOPE VALLEY.

&&

.SHORT TERM (TODAY-FRI)...A STRONG ONSHORE PUSH TODAY BROUGHT
COOLING TO MOST AREAS EXCEPT SOME OF THE MTNS AND ANTELOPE VALLEY.
THIS WILL CONTINUE AND SPREAD FURTHER INLAND THROUGH THE WEEKEND AS
A PERSISTENT TROF SETS UP ALONG THE WEST COAST. SLIGHT DEEPENING OF
THE TROF IS EXPECTED WED AND THU, AND THIS COMBINED WITH A
STRENGTHENING EDDY CIRCULATION (THANKS TO INCREASING OUTER WATER
WINDS) WILL POSSIBLY BE ENOUGH TO GENERATE SOME DRIZZLE DURING THE
OVERNIGHT HOURS ACROSS VENTURA AND LA COUNTIES. THAT INCREASE IN
NORTHWEST FLOW AROUND PT CONCEPTION AND THROUGH THE SANTA YNEZ RANGE
WILL LIKELY KEEP LOW CLOUDS OUT OF SRN SBA COUNTY THE NEXT FEW DAYS
WITH WARMER TEMPS THERE. WINDS WILL BE CLOSE TO OR LOCALLY EXCEEDING
ADVISORY CRITERIA FOR SRN SBA COUNTY, THE I5 CORRIDOR AND THE
ANTELOPE VALLEY STARTING LATE WED.

IF THE MODELS ARE TO BE BELIEVED, THE TROF BRIEFLY LIFTS ON FRIDAY,
RESULTING IN A VERY SLIGHT WARMING TREND FRIDAY, MAYBE A FEW DEGREES
AT MOST, AND EARLIER MARINE LYR CLEARING.

.LONG TERM (SAT-TUE)...TROF DEEPENS AGAIN OVER THE HOLIDAY WEEKEND.
DECREASING NORTHWEST FLOW SHOULD ALLOW THE LOW CLOUDS TO SPREAD UP
THE COAST THROUGH SLO COUNTY AND WE MAY SEE AREAS OF DRIZZLE AGAIN
EACH MORNING THROUGH MONDAY. LIMITED COASTAL CLEARING AND CLOUDS MAY
LINGER INTO EARLY AFTERNOON FOR SOME OF THE VALLEYS. DAYTIME TEMPS
EXPECTED TO RUN 2-4 DEGREES BELOW NORMAL. THE TROF IS EXPECTED TO
SHIFT EAST TUESDAY FOR A WARMING TREND GOING INTO THE MIDDLE OF NEXT
WEEK.

&&

.AVIATION...21/2355Z.

SATELLITE IMAGERY SHOWING LOW CLOUDS SURGING QUICKLY INTO THE LA
COUNTY COASTAL AREAS LATE THIS AFTERNOON...INCLUDING KLAX. CLEARING
BEING OBSERVED TO THE NORTHWEST OF LA COUNTY. LOWER CONFIDENCE IN
LOW CLOUDS RETURNING TO COASTAL AREAS NORTH OF POINT CONCEPTION...WITH
HIGHER PROBABILITY OF CIGS ACROSS LA COUNTY COAST/VALLEYS TONIGHT.
APPEARS THAT EDDY WILL BE STRONG ENOUGH TO BRING LOW CLOUDS BACK
INTO KOXR EARLY WEDNESDAY MORNING. EDDY CIRCULATION EXPECTED TO MAINTAIN
CIGS IN MVFR CATEGORY FOR THE MOST PART...WITH THE EXCEPTION OF A 30 PERCENT
CHANCE OF IFR CONDITIONS IN THE VALLEYS (INCLUDING KBUR AND KVNY).
GUSTY WINDS ACROSS THE PASSES AND CANYONS OF SBA COUNTY THIS EVENING
AND SOMEWHAT STRONGER TOMORROW EVENING...BRINGING A GOOD CHANCE OF LLWS
BOTH EVENINGS. ALSO...GUSTY WEST TO NORTHWEST WINDS WILL BE AFFECTING
KSMX...KSBP...KPMD...AND KWJF THROUGH PERIOD.


KLAX...LOW CLOUDS SURGING IN QUICKLY AS OF 00Z WITH MVFR CIGS ALREADY
OBSERVED. CURRENT THINKING IS THAT LOW CLOUDS WILL LIKELY LINGER FOR
THE NIGHT...BUT THERE IS A 30 PERCENT CHANCE THAT LOW CLOUDS COULD SCOUR
OUT FOR A FEW HOURS LATER THIS EVENING BEFORE RETURNING. CIGS GENERALLY
EXPECTED TO REMAIN IN MVFR CATEGORY.


KBUR...FAIRLY HIGH CONFIDENCE THAT LOW CLOUDS WILL RETURN OVERNIGHT INTO
WEDNESDAY MORNING. LEANING TOWARDS MVFR CATEGORY...BUT A 30 PERCENT CHANCE
OF IFR CONDITIONS.

&&

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

&&

$$

PUBLIC...MW
AVIATION...GOMBERG
SYNOPSIS...KJ

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