083 
FXUS66 KLOX 012115
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
215 PM PDT SUN JUL 1 2012

.SYNOPSIS...
AN UPPER TROUGH OFF THE WEST COAST WILL CAUSE DEEPENING OF THE 
MARINE LAYER THROUGH MID WEEK...WITH NIGHT THROUGH MORNING LOW 
CLOUDS AND FOG EXTENDING FARTHER INTO THE VALLEYS EACH DAY. THERE 
WILL BE A COOLING TREND WEST OF THE MOUNTAINS...WITH BELOW NORMAL 
TEMPERATURES THROUGH THURSDAY. AN UPPER HIGH OVER THE CENTRAL U.S. 
WILL BEGIN TO EXPAND INTO THE REGION LATE IN THE WEEK INTO NEXT 
WEEKEND...BRINGING A REDUCTION IN LOW CLOUDS AND A WARMING TREND.

&&

.SHORT TERM (TONIGHT-WED)...
A BAGGY TROUGH OVER THE WEST COAST WILL WEAKEN AND SHIFT INLAND 
TONIGHT AS AN UPPER LOW IN THE GULF OF ALASKA SWINGS TOWARD THE 
PACIFIC NW. THIS LOW WILL REMAIN IN PLACE THROUGH MIDWEEK AS SEVERAL 
WAVES ROTATE AROUND IT. THIS PATTERN WILL MAINTAIN WEAK TROUGHING 
OVER THE SW CALIFORNIA COAST...DEEPENING SLIGHTLY TONIGHT THROUGH 
MONDAY NIGHT. THE END RESULT WILL BE A CONTINUED DEEPENING OF THE 
MARINE LAYER...WITH LOW CLOUDS MOVING FURTHER INLAND THROUGH THE 
VALLEYS EACH NIGHT AS HEIGHTS ALOFT GRADUALLY DIMINISH. THE STRATUS 
MAY BE ABLE TO ADVANCE AS FAR INLAND AS THE SANTA CLARITA VALLEY 
TONIGHT AND MONDAY NIGHT...DUE TO THE COMBINATION OF LOWERING 
HEIGHTS AND ONSHORE FLOW. EXPECT TO SEE THE MARINE LAYER DEPTH 
BETWEEN 2000 TO 2500 FEET TONIGHT FOR SOUTHERN SECTIONS AND AROUND 
1500 FEET N OF PT CONCEPTION.   

SBA-SMX GRADIENTS ARE SLIGHTLY WEAKER THIS AFTERNOON...AND NAM12 LOW 
LEVEL WINDS INDICATE THAT THE NORTHWEST-NORTH WINDS NEAR/WEST OF 
GAVIOTA WILL BE SOMEWHAT REDUCED COMPARED TO PREVIOUS NIGHTS. EXPECT 
TO SEE LOCAL GUSTS OF 35 TO 40 MPH BELOW PASSES AND CANYONS...BUT 
NOT WIDESPREAD ENOUGH TO WARRANT ANY HIGHLIGHTS. STRONG ONSHORE 
GRADIENTS WILL CONTINUE THROUGH THE SHORT TERM AS THE POSITION OF 
THE UPPER TROUGH REMAINS ESSENTIALLY UNCHANGED...BRINGING GUSTY 
WINDS TO THE MOUNTAINS AND DESERTS EACH AFTERNOON/EVENING PERIOD. 
THIS WILL PRODUCE SLOWER CLEARING OF THE STRATUS EACH 
DAY...ESPECIALLY NEAR THE COAST...AND THE CENTRAL COAST MAY CONTINUE 
TO SEE LOW CLOUDS NEAR THE COAST THROUGH EACH AFTERNOON. 

DAYTIME HIGH TEMPERATURES SHOULD BE DOWN A DEGREE OR TWO EACH DAY 
FOR THE COAST AND VALLEYS...WITH LITTLE CHANGE IN THE MOUNTAINS AND 
DESERTS. 

.LONG TERM (THU-SUN)...
MODELS CONTINUE TO DEPICT THE UPPER TROUGH JUST OFF THE COAST 
THURSDAY...AND BEGIN TO SHIFT IT FURTHER OFFSHORE AS THE CENTRAL 
U.S. RIDGE BUILDS WESTWARD. SLOWLY RISING HEIGHTS WILL COMPRESS THE 
MARINE LAYER THURSDAY INTO FRIDAY...WITH CLOUDS LIMITED TO COASTAL 
AREAS BY FRIDAY MORNING. THE RISING HEIGHTS AND REDUCED ONSHORE FLOW 
WILL PRODUCE A WARMING TREND ACROSS THE AREA...TO CONTINUE THROUGH 
THE EXTENDED WITH INLAND HIGHS IN THE UPPER 80S TO NEAR 100 DEGREES 
BY THE WEEKEND. AS THE RIDGE CONTINUES TO EXPAND WESTWARD INTO SE 
CALIFORNIA...MODELS HINT AT MONSOONAL MOISTURE CREEPING INTO THE SE 
INTERIOR OF THE CWA LATE IN THE EXTENDED.  

&&

.AVIATION...01/1745Z...

LATEST SATELLITE IMAGERY SHOWS STRATUS BURNING OFF QUITE LATE THIS 
MORNING. VFR CONDS SHOULD PREVAIL AT ALL AIRFIELDS THROUGH THIS 
AFTERNOON. FOR TONIGHT...EXPECT A RATHER PERSISTENT STRATUS BEHAVIOR 
AS INVERSION DEPTH SHOULD VARY LITTLE. SO...STRATUS SHOULD RETURN
TO COASTAL TAFS THIS EVENING...AND INTO THE VALLEY TAF OVERNIGHT.
CIGS/VSBYS SHOULD GENERALLY BE AT IFR/LIFR LEVELS OVERNIGHT. 

KLAX...MODERATE CONFIDENCE IN 18Z TAF. STRATUS COULD RETURN AN HOUR 
OR TWO EARLIER THAN CURRENT 06Z FORECAST.

KBUR...MODERATE CONFIDENCE IN 18Z TAF. STRATUS COULD RETURN AN
HOUR OR TWO EARLIER THAN CURRENT 11Z FORECAST. 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...SMITH
AVIATION...RAT
SYNOPSIS...SWEET

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