Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 202331
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
435 PM PDT MON OCT 20 2014

.SYNOPSIS...

A TROUGH OF LOW PRESSURE WILL BRING SLIGHTLY COOLER WEATHER TO THE
AREA THROUGH TUESDAY. THERE WILL BE SOME LOCALLY GUSTY NORTHWEST
WINDS LATE TONIGHT THROUGH TUESDAY NIGHT FOLLOWING THE PASSAGE OF
THIS SYSTEM. A WARMING TREND WILL BEGIN ON WEDNESDAY AS WEAK
OFFSHORE FLOW DEVELOPS...WITH ABOVE NORMAL TEMPERATURES EXPECTED
THROUGH FRIDAY. COOLER WEATHER WILL LIKELY RETURN THIS WEEKEND WITH
THE NEXT LOW PRESSURE SYSTEM.

&&

.SHORT TERM (TODAY-WED)...LATEST SATELLITE IMAGES SHOWED A
WEAKENING COLD FRONT WITH AN AREA OF CLOUDINESS APPROACHING THE
CENTRAL COAST EARLY THIS AFTERNOON. MARINE LAYER CLOUDS THAT COVERED
MUCH OF THE COAST AND VLYS THIS MORNING DISSIPATED IN MOST AREAS BY
EARLY THIS AFTERNOON. THERE WERE SOME LINGERING CLOUDS ALONG THE VTU
COAST AND PARTS OF THE CENTRAL COAST...OTHERWISE MOSTLY SUNNY SKIES
WITH SOME HI CLOUDS COVERED THE REGION. GUSTY S TO W WINDS WERE
NOTED IN THE L.A. COUNTY MTNS AND ANTELOPE VLY.

AN UPPER LEVEL TROF WITH THE SURFACE COLD FRONT WILL APPROACH THE
AREA FROM THE W THROUGH LATE TODAY. THE UPPER TROF WILL QUICKLY MOVE
INLAND ACROSS MAINLY CENTRAL CA TONIGHT WHILE THE COLD FRONT
DISSIPATES OVER SLO/SBA COUNTIES. THIS SYSTEM WILL BRING GUSTY NW
WINDS TO THE L.A./VTU MTNS ALONG THE I-5 CORRIDOR TONIGHT AS WELL AS
GUSTY NW TO N CANYON WINDS TO THE SBA COUNTY S COAST AND MTNS. IT
LOOKS LIKE GUSTS WILL REMAIN JUST BELOW ADVISORY LEVELS EXCEPT
SHOULD REACH THESE LEVELS AT TIMES BELOW AND THRU THE PASSES AND
CANYONS OF THE SBA S COAST. A WIND ADVISORY HAS BEEN ISSUED
FOR THIS AREA FOR THIS EVENING THRU LATE TONIGHT. THE DYING COLD
FRONT WILL ALSO BRING MOISTURE TO THE N MTN SLOPES AND INTO THE FAR
SERN VLYS OF SLO COUNTY AND THE CUYAMA VLY LATER TONIGHT INTO TUE
MORNING...WITH CLOUDINESS AND POSSIBLY A FEW SHOWERS...AND ADDED
POPS TO THESE AREAS FOR THAT PERIOD IN THE AFTERNOON ZONES. SOME LOW
LEVEL OFFSHORE FLOW IS EXPECTED OVER MUCH OF THE REGION TONIGHT AND
TUE MORNING WHICH SHOULD LIMIT MARINE LAYER CLOUDINESS TO THE L.A.
COUNTY COAST AND PORTIONS OF THE SAN GABRIEL VLY. OTHERWISE...MOSTLY
CLEAR TO PARTLY CLOUDY SKIES SHOULD PREVAIL ACROSS MUCH OF THE
REGION THRU TUE. TEMPS ON TUE WILL TURN WARMER ALONG THE COAST AND
ADJACENT VLYS TO NEAR NORMAL FOR THE MOST PART...WITH READINGS STILL
A FEW DEGREES BELOW NORMAL ELSEWHERE.

WEAK UPPER LEVEL RIDGING WHICH SHOULD START TO BUILD INTO SWRN CA ON
TUE WILL BUILD FURTHER ACROSS SRN CA TUE NIGHT AND WED. OFFSHORE
FLOW...LIKELY BELOW ADVISORY LEVELS...WILL COVER MUCH OF THE
FORECAST AREA TUE NIGHT INTO WED MORNING. GUSTY N CANYON WINDS
SHOULD ALSO AFFECT THE SBA S COAST AND MTNS AGAIN...BUT REMAIN BELOW
ADVISORY LEVELS. THE NAM WAS FORECASTING A LINGERING EDDY OVER THE
SRN CA BIGHT INTO WED MORNING WHICH MAY BRING A FEW LOW CLOUDS TO
THE SRN L.A. COUNTY COAST. OVERALL... THOUGH...IT LOOKS LIKE MOSTLY
CLEAR SKIES WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS CAN BE EXPECTED
TUE NIGHT AND WED.

FLAT UPPER LEVEL RIDGING WILL PERSIST OVER SRN CA WED NIGHT AND THU.
IT LOOKS LIKE MORE OFFSHORE FLOW BELOW ADVISORY LEVELS WILL AFFECT
THE AREA DURING THE NIGHT AND MORNING HOURS...EXCEPT THE L.A. COUNTY
COAST WILL REMAIN UNDER THE INFLUENCE OF A WEAK EDDY WITH LATE NIGHT
AND MORNING LOW CLOUDS AND FOG ONCE AGAIN EXPECTED. THE MOSTLY CLEAR
SKIES WILL CONTINUE ELSEWHERE WITH TEMPS WARMING A LITTLE MORE TO
SEVERAL DEGREES ABOVE NORMAL.

.LONG TERM (FRI-MON)...ECMWF/GFS IN PRETTY GOOD AGREEMENT FRI THRU
SAT WITH UPPER RIDGE LINGERING FRI THEN AN UPPER TROF APPROACHES THE
AREA FROM THE E PAC ON SAT. THE GFS DOES BRING A DISSIPATING COLD
FRONT INTO THE CENTRAL COAST ON SAT WITH A FEW SHOWERS POSSIBLE...
WHILE THE EC IS NOT AS FAST AND HOLDS OFF TIL LATE SAT AND SAT
EVENING. BIGGER DIFFERENCES SHOW UP SAT NIGHT INTO EARLY MON AS THE
GFS PASSES THE PROGRESSIVE UPPER TROF QUICKLY E SUN WITH UPPER RIDGE
BUILDING BACK IN BY LATE SUN...WHILE EC SLOWS UPPER TROF DOWN AND
DEVELOPS AN UPPER LOW OVER CENTRAL CA EARLY SUN WITH A BETTER CHANCE
OF RAIN OVER NORTHERN PARTS OF THE FORECAST AREA...THEN MOVES THIS
SYSTEM AWAY SUN AFTERNOON THRU MON AS AN UPPER RIDGE BUILDS IN MON.
TRENDED MORE TOWARD THE GFS SOLUTION AND TIMING OF DISSIPATING FRONT
WITH POSSIBLE SHOWERS OVER PORTIONS OF SLO/SBA COUNTIES SUN. SOME
MARINE LAYER CLOUDS MAY AFFECT THE L.A. COUNTY COAST NIGHT AND
MORNING HOURS...OTHERWISE CLEAR TO PARTLY CLOUDY SKIES ARE EXPECTED.
TEMPS SHOULD COOL SOME BACK TO NEAR NORMAL BY SAT THEN INCREASE TO
NEAR NORMAL TO SLIGHTLY ABOVE NORMAL BY MON.

&&

.AVIATION...20/2330Z.
THE MARINE LAYER AT KLAX AT 2300Z IS 1600 FEET DEEP AND THE
INVERSION TOP IS AT 3000 FEET WITH A TEMPERATURE OF 20 DEGREES C.

WEAK COLD FRONT WASHING OUT ACROSS CENTRAL COAST LATE THIS
AFTERNOON. AS SYSTEM MOVES THROUGH...MARINE INVERSION WILL LIKELY
CONTINUE TO WEAKEN. AS A RESULT...NOT EXPECTING MUCH IN THE WAY
OF ORGANIZED LOW CLOUD COVERAGE TONIGHT ACROSS COASTAL/VALLEY TAF
LOCATIONS. BEST CHANCE OF ANY CIGS DEVELOPING WOULD BE AT KLAX AND
KLGB LATER TONIGHT.

KLAX...LOW CONFIDENCE IN THE 00Z TAF. THERE IS A 50 PERCENT CHANCE
OF VFR CONDITIONS THROUGH THE NEXT 24 HOURS.

KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE OF IFR CONDITIONS LATE TONIGHT INTO EARLY TUESDAY MORNING.

&&

.MARINE...20/200 PM...

MADE NUMEROUS CHANGES TO THE MARINE FORECAST AS PER THE LATEST
GUIDANCE. GENERALLY GOOD CONFIDENCE IN THE MORNING FORECAST UNLESS
OTHERWISE STATED. THE LATEST GUIDANCE SHOWS A PRETTY GOOD SHOT AT
SMALL CRAFT ADVISORIES FOR THE OUTER WATERS LATE THIS AFTERNOON
THROUGH TONIGHT. THERE IS FAIR CONFIDENCE IN SMALL CRAFT ADVISORIES
FOR THE NEAR SHORE WATERS ON THE CENTRAL COAST AND WESTERN PORTIONS
OF THE SANTA BARBARA CHANNEL AS WELL. MADE AREA AND TIMING CHANGES
TO THE GALE WATCH FOR TUESDAY SINCE THE GALES ARE NOT LIKELY UNTIL
LATE IN THE DAY AND THEY MAY NOT AFFECT THE NORTHERN OUTER WATERS.
THERE IS ONLY FAIR CONFIDENCE AT BEST FOR THE GALE WATCH WITH MARINE
ZONES 673 AND 676 HAVING THE BEST CHANCE OF SEEING FREQUENT GUSTS TO
35 KNOTS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
SMALL CRAFT ADVISORY AND GALE WATCH (SEE LAXMWWLOX).

&&
$$

PUBLIC...SIRARD
AVIATION...GOMBERG
MARINE...SWEET
SYNOPSIS...SIRARD

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