593  
FXUS66 KLOX 232347  
AFDLOX  
 
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
440 PM PDT THU MAY 23 2013  
   
..UPDATED AVIATION DISCUSSION  
 
   
SYNOPSIS  
 
GUSTY NORTHWEST WINDS WILL CONTINUE TONIGHT ACROSS THE  
MOUNTAINS...DESERTS...AND PORTIONS OF THE CENTRAL COAST. LOW  
PRESSURE WILL LINGER OVER THE WESTERN UNITED STATES THROUGH EARLY  
NEXT WEEK WITH AREAS OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG.  
TEMPERATURES WILL STAY BELOW NORMAL THROUGH EARLY NEXT WEEK...THEN A  
WARMING TREND SHOULD BEGIN BY MIDWEEK AS LOW PRESSURE MOVES EAST.  
 
 
   
SHORT TERM (TONIGHT-SUN)  
 
STRATOCUMULUS HAS HUNG IN THERE ALL DAY ACROSS AREAS OF VENTURA AND  
LOS ANGELES COUNTIES...AND LITTLE CHANGE HAS OCCURRED WITH THE  
MARINE INVERSION TODAY. AFTERNOON HIGHS STAYED THE COURSE OF MANY  
DEGREES COOLER THAN YESTERDAY IN MOST AREAS. WINDS INCREASED ALONG  
THE CENTRAL COAST...MOUNTAINS...AND ANTELOPE VALLEY THIS AFTERNOON.  
ONSHORE PRESSURE GRADS ARE NOT AS STRONG AS YESTERDAY AND SPEEDS ARE  
REFLECTING THIS. EXPECT LOW-END WIND ADVISORIES TO CONTINUE INTO THE  
EVENING/NIGHT AS PLANNED.  
 
MARINE INVERSION REMAINS ABOVE 4K FEET THIS AFTERNOON. MODEL 30AGL  
HUMIDITY SHOWS LOW CLOUDS REFORMING IN A SIMILAR FASHION AS LAST  
NIGHT ACROSS VENTURA AND LOS ANGELES COUNTIES...ALTHOUGH THE EDDY IS  
NOT AS ROBUST BY FRIDAY MORNING SO THERE COULD BE A LITTLE MORE  
RAGGED LOOK TO THE CLOUD DECK. ALONG THE CENTRAL COAST WINDS TURN  
SLIGHTLY OFFSHORE SO DON'T EXPECT CLOUDS TO FORM OVERNIGHT.  
 
VERY LITTLE CHANGES FOR THE WEEKEND. THE LOW PRESSURE SYSTEM OVER  
THE PACIFIC NORTHWEST REMAINS STATIONARY WITH HEIGHTS REMAINING  
STATIC OVER SOUTHERN CA THROUGH SUNDAY. TEMPERATURES WILL BE A  
COUPLE OF DEGREES HIGHER THAN TODAY BUT THAT'S ABOUT IT. NIGHT AND  
MORNING LOW CLOUDS AND PATCHY FOG SHOULD RETURN ALONG THE SOUTH  
COAST AND REORGANIZE ALONG THE CENTRAL COAST OVER THE WEEKEND.  
   
LONG TERM (MON-THU)  
 
THE LONG RANGE BECOMES A LITTLE MORE FUZZY WITH LOWER FORECAST  
CONFIDENCE FOR MONDAY AND TUESDAY. WITH THE PAC NORTHWEST LOW  
PRESSURE SYSTEM STALLING OUT...THIS ALLOWS TIME FOR A STRONGER  
NORTHWEST JET STREAM TO REACH THE EASTERN PAC AND DIG DOWN THE  
BACKSIDE OF THE LOW PRESSURE TROUGH. BY TUESDAY MORNING THIS JET  
STREAM IS RAPIDLY PUSHING 90+KTS ALONG THE CENTRAL COAST AS THE  
TROUGH AMPLIFIES ACROSS THE GREAT BASIN. THE ECMWF HAS BEEN THE MOST  
AGGRESSIVE FOR THE PAST TWO RUNS...BUT THE GFS IS ALSO SHOWING  
ENOUGH TO WARRANT A SLIGHT CHANCE OF SHOWERS LATE MONDAY NIGHT  
THROUGH TUESDAY EVENING. GUSTY NORTHWEST WINDS MAY TURN OUT TO THE  
BIGGER STORY FOR THE CENTRAL COAST...MOUNTAINS...AND AV DURING THIS  
TIME FRAME. THE TROUGH LOOKS PROGRESSIVE AND SHOULD CLEAR SOUTHERN  
CA BY WEDNESDAY BUT IT MAY REMAIN RATHER WINDY IN PLACES. EXPECT  
TEMPERATURES TO BE BELOW NORMAL EARLY IN THE WEEK THEN WARMING AS A  
RIDGE BUILDS IN MID-WEEK.  
 
 
   
AVIATION  
23/2335Z.  
 
SATELLITE IMAGERY SHOWING SOME STRATOCUMULUS CLOUDS LINGERING ACROSS THE  
LA COUNTY VALLEYS AND MOUNTAINS THIS AFTERNOON...OTHERWISE SKIES ARE MOSTLY  
CLEAR. A PERSISTENT EDDY CIRCULATION IS EXPECTED TO MAINTAIN LOW CLOUDS  
ACROSS MUCH OF THE LA BASIN TONIGHT...POTENTIALLY SPREADING INTO PORTIONS  
OF VENTURA COUNTY LATE. ONLY 20 PERCENT CHANCE OF LOW CLOUDS REDEVELOPING  
ALONG CENTRAL COAST. GUSTY ONSHORE WINDS CONTINUE ACROSS CENTRAL COAST  
AND ANTELOPE VALLEY...HOWEVER SPEEDS ARE NOT AS STRONG AS YESTERDAY.  
 
KLAX...HIGH CONFIDENCE THAT MVFR CIGS WILL RETURN AT SOME POINT  
TONIGHT...BUT LOW CONFIDENCE IN TIMING. A 10% CHANCE THAT VFR CONDITIONS  
COULD LINGER THROUGH THE NIGHT.  
 
KBUR...HIGH CONFIDENCE THAT MVFR CIGS WILL RETURN AT SOME POINT  
TONIGHT...BUT LOW CONFIDENCE IN TIMING. A 10% CHANCE THAT VFR  
CONDITIONS COULD LINGER THROUGH THE NIGHT.  
 
 
   
LOX WATCHES/WARNINGS/ADVISORIES  
 
WIND ADVISORY (SEE LAXNPWLOX).  
GALE WARNING (SEE LAXMWWLOX).  
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).  
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).  
 
 
 
 
 
PUBLIC...BOLDT  
AVIATION...SMITH  
SYNOPSIS...SUKUP  
 
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