Area Forecast Discussion


114 
FXUS66 KLOX 130548
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 PM PDT MON AUG 12 2013
UPDATED AVIATION DISCUSSION
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO RETURN TO NORMAL OR A LITTLE ABOVE BY 
MIDWEEK AS THE RIDGE CONTINUES TO SLOWLY BUILD INTO THE AREA. NIGHT 
THROUGH MORNING LOW CLOUDS AND FOG SHOULD BE MAINLY CONFINED TO THE 
COASTAL PLAIN THE REST OF THE WEEK. A WEAK TROUGH MAY COOL 
TEMPERATURES A COUPLE DEGREES OVER THE WEEKEND.
&&
.SHORT TERM (TONIGHT-THU)...DOWNTOWN LOS ANGELES HAD A HIGH OF 79 
DEGREES TODAY...FOR THE 17TH CONSECUTIVE DAY THE HIGH THERE DID NOT 
REACH 80. THIS INCLUDES 12 CONSECUTIVE SUB-80 DEGREE HIGHS TO START 
THE MONTH OF AUGUST...SETTING A NEW RECORD. THE AVERAGE HIGH FOR 
AUGUST 2013 AT DOWNTOWN L.A. THRU TODAY IS 77.5 DEGREES WHICH IS 6.9 
DEGREES BELOW NORMAL. IT LOOKS LIKE THIS STRETCH OF BELOW 80 DEGREE 
HIGHS WILL END ON TUESDAY AS THE FORECAST HIGH FOR DOWNTOWN IS 81.
THE MARINE INVERSION WAS NEAR 1200 FT DEEP AT LAX EARLY THIS 
EVENING. LOW CLOUDS WERE MOVING INTO PORTIONS OF THE CENTRAL COAST 
THIS EVENING AND WILL CONTINUE TO EXPAND ALONG THE COAST AND INLAND 
TO THE SANTA YNEZ VALLEY OVERNIGHT. LOW CLOUDS WERE ALSO NOTED ALONG 
PORTIONS OF THE VTU/L.A. COUNTY COASTAL AREAS...AND ARE EXPECTED TO 
GRADUALLY EXPAND ALONG THE COAST AND PUSH INLAND TO THE SOME OF THE 
ADJACENT VALLEYS OVERNIGHT IN RESPONSE TO THE DEVELOPMENT OF A WEAK 
EDDY. THE S COAST OF SBA COUNTY SHOULD REMAIN MOSTLY CLEAR UNTIL 
VERY LATE TONIGHT OR EARLY TUE. OTHERWISE...MOSTLY CLEAR SKIES WILL 
PREVAIL OVER THE REGION THRU THE NIGHT.
THE LATEST MODEL RUNS INDICATED THAT A BROAD UPPER LEVEL TROF WILL 
LINGER ALONG AND OFF THE CA COAST THRU TUE NIGHT...THEN UPPER 
RIDGING WILL SLOWLY BUILD INTO SRN CA FROM THE E WED THRU THU. THE 
MARINE LAYER PATTERN WITH VARYING AMOUNTS OF NIGHT AND MORNING LOW 
CLOUDS AND FOG WILL PREVAIL MAINLY FOR PORTIONS OF THE COASTAL PLAIN 
THE PERIOD. OTHERWISE...MOSTLY CLEAR SKIES WILL CONTINUE OVER THE 
FORECAST AREA THROUGH THU. DECENT ONSHORE FLOW CAN BE EXPECTED FOR 
THE AFTERNOON AND EVENING HOURS...WITH SOME GUSTY WINDS EXPECTED FOR 
PORTIONS OF THE MTNS AND ACROSS THE ANTELOPE VALLEY. THERE SHOULD 
ALSO BE SOME OFFSHORE FLOW LATER AT NIGHT INTO THE MORNING FOR 
INTERIOR AREAS OF SLO/SBA COUNTIES. TEMPS ARE EXPECTED TO WARM TO 
NEAR NORMAL TO SEVERAL DEGREES ABOVE NORMAL FOR TUE AND WED...THEN 
WARM FURTHER TO ABOVE NORMAL FOR MANY AREAS ON THU.
***FROM PREVIOUS DISCUSSION***
.LONG TERM (FRI-MON)...OVERALL...12Z MODELS CONTINUE TO EXHIBIT GOOD 
SYNOPTIC AGREEMENT THROUGH THE PERIOD. AT UPPER LEVELS...RIDGE WILL
PEAK IN STRENGTH ON FRIDAY...THEN WILL BE SQUASHED A BIT SATURDAY 
AND SUNDAY AS A WEAK TROUGH ZIPS ACROSS NORTHERN CALIFORNIA...THEN
THE RIDGE WILL RECOVER ON MONDAY. NEAR THE SURFACE...EAST/WEST 
GRADIENTS WILL REMAIN ONSHORE WHILE NORTH/SOUTH GRADIENTS REMAIN 
WEAKLY OFFSHORE.
FORECAST-WISE...ONLY MINOR CHANGES ARE EXPECTED THROUGH THE PERIOD. 
TEMPERATURES WILL LIKELY EXHIBIT A SLIGHT COOLING TREND THROUGH THE 
PERIOD BUT WILL STILL HOVER NEAR SEASONAL NORMS. AS FOR THE MARINE
LAYER STRATUS...WILL EXPECT A SLIGHT INCREASE IN DEPTH AND INLAND
EXTENT...BUT THE MARINE LAYER ITSELF MAY HAVE DIFFERENT IDEAS. 
&&
.AVIATION...13/0545Z...EXPECT WIDESPREAD STRATUS IN ALL COASTAL 
AREAS...ARRIVING LAST ACROSS THE S COAST OF SANTA BARBARA COUNTY. 
SOME CLOUDS MAY SNEAK INTO THE LOWER COASTAL VLYS OF L.A. AND VTU 
COUNTIES AND THE SANTA YNEZ VALLEY OVERNIGHT. CONDS WILL BE 
GENERALLY IFR IN THESE AREAS. EXPECT FAIRLY QUICK CLEARING BY MID OR 
LATE MORNING ACROSS THE REGION. LESS IN THE WAY OF INLAND 
PENETRATION OF STRATUS EXPECTED TUE NIGHT.
KLAX...MODERATE CONFIDENCE IN THE 06Z TAF. THERE IS A 20 PERCENT 
CHANCE CIGS WILL SCATTER OUT BETWEEN 06Z AND 10Z. THERE IS A 10 TO 
20 PERCENT CHANCE CIGS WILL LINGER AT IFR LEVELS THROUGH 19Z OR 
20Z.
KBUR...MODERATE CONFIDENCE IN THE 06Z TAF. THERE IS A 20 TO 30 
PERCENT CHANCE IFR CIGS BETWEEN 10Z AND 16Z.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...SIRARD/RAT
AVIATION...SIRARD
SYNOPSIS...B
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