000
FXUS66 KLOX 191924
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1220 PM PDT FRI SEP 19 2008

NEW AVIATION DISCUSSION

.SHORT TERM...SKIES WERE CLEAR ACROSS THE ENTIRE AREA THIS MORNING...
AND ARE EXPECTED TO REMAIN SO TODAY. UPPER LOW OFF THE COAST OF NRN
CA WILL LIFT NEWD AND OPEN UP LATER TODAY AND TONIGHT. THE SRN END
OF THE WEAKENING SFC BOUNDARY ASSOCD WITH THIS SYSTEM WILL MOVE
THROUGH THE FCST AREA LATER TODAY AND TONIGHT. SOME COOLING AT 850
MB BEHIND THIS BOUNDARY MAY BRING SLIGHT COOLING TO INTERIOR
SECTIONS N OF PT CONCEPTION TODAY. WITH LITTLE CHANGE IN 850/950 MB
ELSEWHERE...AND ONLY A SLIGHT INCREASE IN ONSHORE GRADS...EXPECT
MOSTLY MINOR CHANGES IN MAX TEMPS TODAY COMPARED TO THOSE REACHED
THU.

LOW LVL NLY GRADS ARE FCST TO INCREASE ACROSS THE CENTRAL COAST
LATER TODAY AND TONIGHT...AND THERE WILL SOME DECENT SUBSIDENCE AND
A PERIOD OF FAIRLY NW TO NLY WINDS OF UP TO 30 KT ACROSS SRN SBA
COUNTY TONIGHT. EXPECT SOME GUSTY WINDS ON THE CENTRAL COAST THIS
AFTERNOON...AND THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY
TONIGHT. WINDS COULD APCH ADVISORY LEVELS IN THE SANTA YNEZ MTNS AND
BELOW ADJACENT PASSES AND CANYONS OF SRN SBA COUNTY TONIGHT.

THE WRF IS SHOWS AN EDDY CRCLN TRYING TO DEVELOP LATE TONIGHT...WITH
SOME INCREASE IN LOW LVL MOISTURE ACROSS AT LEAST  COAST SECTIONS OF
L.A. AND POSSIBLY VTU COUNTIES. STILL...DO NOT EXPECT WDSPRD STRATUS
TONIGHT/SAT MORNING...AND WHAT OCCURS WILL LIKELY BE CONFINED TO THE
L.A. COUNTY COAST. WHILE THICKNESS VALUES CHANGE LITTLE...INCREASING
ONSHORE GRADS AND SOME COOLING AT 850 AND 950 MB SHOULD KNOCK A FEW
DEGREES OFF MAX TEMPS IN MOST AREAS ON SAT...WITH TEMPS GENERALLY
SLIGHTLY BELOW NORMAL ACROSS THE FCST AREA.

THERE COULD AGAIN BE SOME LOCALLY GUSTY WINDS THRU AND BELOW PASSES
AND CANYONS OF SRN SBA COUNTY SAT NIGHT...BUT THEY ARE NOT EXPECTED
TO BE AS STRONG AS ANY UPPER SUPPORT FADES. GUSTY WINDS MAY ALSO
AFFECT THE I5 CORRIDOR SAT NIGHT. BROAD CYCLONIC FLOW ALF WILL CONT
ACROSS THE AREA SAT NIGHT AND SUNDAY...WITH MINOR CHANGES IN
HEIGHTS/THICKNESSES. THERE WILL PROBABLY BE SOMEWHAT MORE IN THE WAY
OF NIGHT THRU MORNING LOW CLOUDS AND FOG IN CSTL SXNS OF L.A. AND
VTU COUNTIES AND ON THE CENTRAL COAST...AND SOME CLOUDS COULD SPREAD
INTO THE SAN GABRIEL VALLEY. THERE COULD BE SOME SLIGHT COOLING ON
SUNDAY...ESPECIALLY IN CSTL AND VLY AREAS AS 950 MB TEMPS DROP A BIT
MORE.

.LONG TERM...THERE WILL BE LITTLE CHANGE IN THE UPPER PATTERN SUN
NIGHT AND MONDAY. THE WRF SUGGESTS A MORE WIDESPREAD AND INVASIVE
STRATUS FIELD SUN NIGHT/MON MORNING...WITH CLOUDS PROBABLY SPREADING
INTO MOST VLY AREAS. WITH THE INCREASED CLOUD COVER...THERE WILL
LIKELY BE ADDITIONAL COOLING IN CSTL AND VALLEY AREAS MON. HEIGHTS
BEGIN TO RISE ON TUE AS RIDGING AMPLIFIES OFF THE W CST. EXPECT SOME
WARMING IN MOST AREAS ON TUE...AND THE MARINE LAYER SHOULD BECOME
MORE SHALLOW. AN UPPER HIGH OFF THE CST IS FCST TO MOVE RIGHT OVER
THE AREA WED AND LINGER THRU THU. AT THE SAME TIME...LOW LVL ONSHORE
GRADS WILL TURN WEAKLY OFFSHORE OR AT LEAST NEUTRAL WED MORNING
AND THU MORNING. IF THIS OCCURS...EXPECT A SHARP REDUCTION IN THE
STRATUS...WITH CLDS LIKELY CONFINED TO THE CST DURG THE LATE NIGHT
THRU MORNING HOURS WED AND THU. SIGNIFICANT WARMING IS EXPECTED
WED...ESPECIALLY IN THE VALLEYS AND ACROSS INTERIOR SXNS OF THE CSTL
PLAIN...WITH SLIGHT ADDITIONAL WARMING THU AS THICKNESSES EDGE
UPWARD.

&&

.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...BRUNO
AVIATION...SWEET

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