Expires:No;;620190
WWUS86 KLOX 200521
SPSLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
921 PM PST THU JAN 19 2012
.SYNOPSIS...
A COUPLE OF STORM SYSTEMS WILL MOVE ACROSS THE REGION THROUGH MONDAY 
WITH POSSIBLE PRECIPITATION AND BREEZY WINDS. THE FIRST STORM WILL 
REACH SAN LUIS OBISPO COUNTY LATER TONIGHT AND MOVE SOUTH INTO LOS 
ANGELES COUNTY BY LATE FRIDAY...WITH PRECIPITATION POSSIBLE INTO 
SATURDAY AFTERNOON. THEN THERE WILL BE A BREAK BETWEEN STORMS WITH 
THE NEXT PRECIPITATION FORECASTED FOR SUNDAY NIGHT INTO MONDAY. A 
HIGH IS EXPECTED BY TUESDAY WITH OFFSHORE WINDS AND A WARMING TREND 
INTO THURSDAY.
&&
.SHORT TERM (TONIGHT-SUN)...FAIR SKIES COVERED THE FORECAST AREA 
THIS EVENING WITH PLENTY OF MID AND HI LEVEL CLOUDS ESPECIALLY FOR 
SLO/SBA COUNTIES. THE CLOUDS WILL CONTINUE TO INCREASE MAINLY N OF 
PT CONCEPTION OVERNIGHT AS A WEATHER SYSTEM APPROACHES THE REGION. A 
SLIGHT CHANCE OF SHOWERS IS ALSO EXPECTED OVERNIGHT N OF POINT 
CONCEPTION. GUSTY W WINDS IN THE ANTELOPE VALLEY ARE EXPECTED TO 
DIMINISH OVERNIGHT.
A WEAK UPPER RIDGE IS EXPECTED OVER SRN CA ON FRI...WITH A FAST 
MOVING UPPER TROF OVER THE ERN PAC FORECASTED TO MOVE INTO CENTRAL 
CA LATE FRI NIGHT AND SAT MORNING. THIS SYSTEM WILL MOVE QUICKLY E 
INTO THE SRN GREAT BASIN BY EARLY SAT EVENING. A BROAD W FLOW ALOFT 
IS EXPECTED OVER THE AREA FOR LATER SAT NIGHT AND SUN. A WARM FRONT 
WILL BRING SHOWERS MAINLY TO SLO/SBA COUNTIES ON FRI. RAIN WILL 
SPREAD S INTO VTU/L.A. COUNTIES FRI NIGHT INTO SAT MORNING AS A COLD 
FRONT MOVES ACROSS THE REGION. IT LOOKS LIKE THE FRONT WILL MOVE 
QUICKLY E BY EARLY SAT AFTERNOON WITH THE CHANCES OF RAIN 
DIMINISHING FROM NW TO SE OVER THE FORECAST AREA. IT LOOKS LIKE THIS 
WEATHER SYSTEM WILL BRING LIGHT TO MODERATE AMOUNTS OF RAINFALL TO 
THE AREA WITH ABOUT ONE HALF AND ONE INCH OF PRECIPITATION NORTH OF 
POINT CONCEPTION...ALTHO LOCALLY HIGHER AMOUNTS UP TO 3 INCHES WILL 
BE POSSIBLE IN THE FOOTHILLS OF NORTHWESTERN SAN LUIS OBISPO COUNTY. 
AREAS SOUTH OF POINT CONCEPTION SHOULD RECEIVE BETWEEN ONE QUARTER 
AND THREE QUARTERS OF AN INCH OF PRECIPITATION. SNOW LEVELS WILL BE 
GENERALLY ABOVE 9000 FEET THRU SAT SO ANY SNOWFALL WOULD OCCUR AT 
THE VERY HIGHEST PEAKS. IN ADDITION TO THE RAIN...STRONG AND GUSTY W 
TO SW WINDS ARE EXPECTED IN THE HIGHER MTNS AND ANTELOPE VALLEY ON 
SAT...WHERE WIND ADVISORIES MAY BE NEEDED.
DRY WEATHER AHEAD OF THE NEXT WEATHER SYSTEM IS THEN FORECAST FOR 
SAT NIGHT AND SUN AS DRY OFFSHORE FLOW DEVELOPS OVER THE REGION THRU 
SUN MORNING. HI TEMPS ARE EXPECTED TO BE SEVERAL DEGREES BELOW 
NORMAL TO NEAR NORMAL DURING THE PERIOD...ALTHO SUN SHOULD HAVE THE 
WARMEST TEMPS.
***FROM PREVIOUS DISCUSSION***
.LONG TERM (MON-THU)...THE SECOND SYSTEM IS STILL LOOKING 
CONSIDERABLY WEAKER THAN THE FIRST AND IT'S QUITE POSSIBLE THAT 
AREAS SOUTH OF SBA COUNTY WILL GET LITTLE TO NO MEASURABLE RAIN. 
POPS ARE ON THE LOW SIDE AS A RESULT. AT BEST MAYBE AN ADDITIONAL 
TENTH OF AN INCH, MAINLY NORTH OF PT CONCEPTION. A LITTLE BIT OF 
COOLING MONDAY WITH THE INCREASE IN CLOUDS AND POSSIBLE LIGHT 
PRECIP. THEN TURNING RAPIDLY WARMER THROUGH MID WEEK AS STRONG HIGH 
PRESSURE ALOFT RETURNS ALONG WITH WEAK OFFSHORE FLOW. BY WED AND THU 
WE SHOULD SEE VALLEYS AND EVEN SOME INTERIOR COASTAL ZONES SOUTH OF 
PT CONCEPTION BACK INTO THE 80S.
&&
.AVIATION...20/0045Z...MODERATE CONFIDENCE OVERALL IN THE CURRENT 
TAF PACKAGE DUE TO UNCERTAINTIES IN TIMING OF ONSET OF LOW CLOUDS 
AND MVFR/IFR CONDITIONS AT SEVERAL TAF SITES DURING THE PERIOD. 
THESE CONDITIONS ARE EXPECTED TO MOVE INTO KPRB...KSBP...KSMX AND 
KSBA MAINLY MID TO LATE FRI MORNING THRU THE AFTERNOON BUT CIGS 
HEIGHTS MAY NOT BE AS LOW AS FORECAST AND COULD REMAIN ABOVE IFR. 
LOW CLOUDS AND MVFR CIGS ARE ALSO EXPECTED TO FORM AT KLAX AND KLGB 
LATE TONIGHT AND PERSIST INTO FRI MORNING...AND AT KOXR FOR FRI 
AFTERNOON...BUT AGAIN THERE ARE UNCERTAINTIES IN THE TIMING OF THE 
LOW CLOUDS. FOR KBUR...KVNY...KWJF AND KPMD THERE IS HI CONFIDENCE 
VFR CONDITIONS WILL PREVAIL TONIGHT THRU FRI. GUSTY W TO NW WINDS AT 
KWJF AND KPMD WILL DIMINISH TONIGHT THEN INCREASE AGAIN FRI 
AFTERNOON.
KLAX...MODERATE CONFIDENCE IN THE CURRENT TAF DUE TO UNCERTAINTIES 
IN THE TIMING OF LOW CLOUDS AND MVFR CONDITIONS LATE TONIGHT INTO 
FRI MORNING....AND AGAIN FRI AFTERNOON INTO FRI EVENING...WITH IFR 
CONDITIONS EXPECTED BY 03Z. THE LOW CLOUDS COULD COME EARLIER THAN 
FORECAST TONIGHT...AND IFR CIGS COULD COME IN EARLIER THAN FORECAST 
FRI EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED TONIGHT UNTIL 
ABOUT 12Z...AND FROM 16Z-23Z FRI.
KBUR...HI CONFIDENCE IN THE CURRENT TAF WITH VFR CONDITIONS EXPECTED 
TONIGHT THRU FRI.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX)
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...SIRARD/WOFFORD
AVIATION...SIRARD
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES