000
FXUS66 KLOX 180543 AAA
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 PM PDT FRI SEP 17 2010
UPDATED AVIATION SECTION
.SYNOPSIS...HIGH PRESSURE WILL REMAIN JUST EAST OF THE REGION
THROUGH SUNDAY...WITH LOW PRESSURE OVER THE PACIFIC...KEEPING
TEMPERATURES GENERALLY NEAR NORMAL IN MOST AREAS THROUGH SUNDAY. A
COOLING TREND IS EXPECTED MONDAY THROUGH WEDNESDAY AS A TROUGH MOVES
INTO THE WESTERN STATES...WITH BELOW NORMAL TEMPERATURES EVERYWHERE.
GUSTY NORTHWEST WINDS EXPECTED SUNDAY NIGHT THROUGH TUESDAY.
&&
.SHORT TERM (TONIGHT-MON)...THE MARINE LAYER REMAINED SHALLOW AT 800
FT DEEP THIS EVENING AT LAX. LOW CLOUDS HAVE MOVED INLAND ALONG THE
CENTRAL COAST THIS EVENING...AND WERE GENERALLY ALONG THE IMMEDIATE
COAST OF L.A./VTU/S SBA COUNTIES. THE LOW CLOUDS WILL SLOWLY EXPAND
ALONG THE COASTAL PLAIN OVERNIGHT BUT BECAUSE OF THE SHALLOW MARINE
INVERSION LITTLE IF ANY EXTENSION OF THE LOW CLOUDS INTO THE
ADJACENT VALLEYS IS EXPECTED...EXCEPT FOR THE SANTA YNEZ VALLEY.
PATCHY DENSE FOG WILL BE LIKELY OVERNIGHT AS WELL FOR COASTAL AREAS
AND SANTA YNEZ VALLEY. THERE IS ALSO THE CHANCE THE DENSE FOG COULD
BECOME WIDESPREAD ENOUGH OVER THE COASTAL PLAIN THAT A DENSE FOG
ADVISORY MAY BE NEEDED. THERE MAY BE PATCHY LOW CLOUDS AND DENSE FOG
DEVELOPING IN THE SALINAS VALLEY LATE TONIGHT AS WELL. OTHERWISE
MOSTLY CLEAR SKIES ARE EXPECTED FOR ALL INLAND AREAS TONIGHT.
AN UPPER LEVEL RIDGE IS FORECAST TO LINGER OVER EXTREME SRN CA THRU
SAT. THE RIDGE WILL MOVE E FOR SUN...WITH A BROAD UPPER LEVEL TROF
EXPECTED TO APPROACH THE AREA FROM THE E PAC. THE UPPER TROF IS
EXPECTED TO PUSH THROUGH CENTRAL AND NRN CA SUN NIGHT AND MON. THE
MARINE LAYER PATTERN WILL LINGER...WITH VARYING AMOUNTS OF NIGHT AND
MORNING LOW CLOUDS AND FOG ALONG THE COASTAL PLAIN...ALTHO BY SUN
NIGHT THE LOW CLOUDS MAY BE MUCH LESS ORGANIZED OVER THE CENTRAL
COAST...AND SHOULD START TO MOVE FURTHER INLAND OVER VTU/L.A.
COUNTIES. LOW CLOUDS AND FOG MAY ALSO AFFECT THE SALINAS RIVER
VALLEY FOR THE LATE NIGHT AND EARLY MORNING HOURS DURING THE PERIOD.
OTHERWISE...MOSTLY CLEAR SKIES ARE EXPECTED OVER THE REGION DURING
THE PERIOD...EXCEPT SOME CLOUDINESS MAY MOVE INTO PORTIONS OF
SLO/SBA COUNTIES FOR MON. WINDS WILL BE GENERALLY LIGHT FOR THE
OVERNIGHT AND MORNINGS...WITH INCREASING ONSHORE FLOW DURING THE
AFTERNOON EACH DAY AS GUSTY NW WINDS SHOULD AFFECT THE CENTRAL
COAST...AND GUSTY SW WINDS CAN BE EXPECTED FOR THE ANTELOPE VALLEY.
GUSTY N CANYON WINDS SHOULD ALSO AFFECT THE SBA COUNTY S COAST AND
MTNS SAT EVENING AND EVEN MORE SO SUNDAY EVENING. TEMPS ARE EXPECTED
TO BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL OVER THE REGION SAT AND
SUN...THEN COOL TO SLIGHTLY BELOW NORMAL FOR MANY AREAS ON MON.
***FROM PREVIOUS DISCUSSION***
.LONG TERM (TUE-FRI)...GUSTY NORTHERLY FLOW WILL CONTINUE INTO
TUESDAY...BUT SHOULD SLOWLY WEAKEN OVER THE NEXT COUPLE OF DAYS.
ADVISORY LEVEL WIND CONCERNS WILL CONTINUE OVER THE FAVORED AREAS
PREVIOUSLY MENTIONED. THE AIRMASS LOOKS TO BOTTOM OUT ON TUESDAY AND
WEDNESDAY AS THICKS REMAIN LOW AND GENERAL TROUGHINESS
PERSISTS...WITH TEMPERATURES WELL BELOW NORMAL. THE ONE WRINKLE TO
THAT IS WEAK OFFSHORE GRADS TUE MORNING...WHICH COULD END UP WARMING
THE COASTS SOME AND BRINGING QUICK STRATUS CLEARING. OVERALL...THE
MARINE LAYER SHOULD DEEPEN WITH LOW 500MB HEIGHTS AND A COASTAL EDDY.
THURSDAY AND FRIDAY LOOK TO BRING SOME RELIEF AS OF NOW...WITH A
RIDGE FROM THE SOUTHEAST STARTING TO BUILD IN. MODEL RUN-TO-RUN
CONSISTENCY HAS BEEN SHAKY...SO CANNOT PUT TOO MUCH FAITH IN
THAT...BUT A WARM UP SHOULD FOLLOW EVENTUALLY.
&&
.AVIATION...18/0545Z...EXPECT WDSPRD IFR TO LIFR CONDS IN ALL CSTL
SXNS OVERNIGHT AND SAT MORNING...WITH CLOUDS AND IFR CIGS LINGERING
AT SOME BEACHES THROUGH SAT AFTERNOON. TOUGH CALL ABOUT THE VALLEYS
ONCE AGAIN. ODDS FAVOR SKIES REMAINING MOSTLY CLEAR WITH THE
EXCEPTION OF THE SANTA YNEZ AND SALINAS VALLEYS...BUT THERE IS SOME
CHANCE IFR/LIFR CONDS COULD AFFECT KBUR AND KVNY.
KLAX...MODERATE CONFIDENCE IN THE CURRENT TAF. THERE IS A 10 TO 20
PERCENT CHANCE VSBYS WILL RISE ABOVE 1/2SM IN FG BY 10Z. THERE IS A
20 PERCENT CHANCE CIGS WILL LINGER THRU 22Z.
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 20 TO 30 PERCENT
CHANCE OF IFR/LIFR CONDS BETWEEN 10Z AND 16Z.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...SIRARD/KITTELL
AVIATION...DB
SYNOPSIS...BB
WWW.WEATHER.GOV/LOSANGELES
