Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 221633
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 AM PST MON DEC 22 2014

.SYNOPSIS...

HIGH PRESSURE WILL MOVE IN AND BRING GUSTY OFFSHORE WINDS...ABOVE
NORMAL TEMPERATURES AND FAIR SKIES INTO MIDWEEK. ON CHRISTMAS DAY
A SYSTEM WILL MOVE INTO THE GREAT BASIN...RESULTING IN CLOUDIER AND
COOLER CONDITIONS THROUGH FRIDAY. THE WEEKEND TEMPERATURES SHOULD
WARM TO ABOVE NORMAL AS A HIGH BUILDS IN.

&&

.SHORT TERM (TODAY-WED)...
OVERALL...MAIN FOCUS THIS MORNING CONTINUES TO BE WINDS. STRONG
NORTHERLY WINDS THAT DEVELOPED SUNDAY AFTERNOON AND CONTINUED LAST
NIGHT CONTINUE TO SLOWLY DIMINISH AS THE FLOW TURNS MORE TO THE
NORTHEAST. AT 900 AM...WILL LET THE WIND ADVISORIES FOR THE SBA
COUNTY SOUTH COAST/MOUNTAINS EXPIRE...BUT STILL MENTION SOME LOCALLY
GUSTY WINDS AROUND THE MONTECITO AREA THIS MORNING.

WITH THE NORTH WINDS WINDING DOWN...ATTENTION TURNS TO THE NORTHEAST
WINDS TONIGHT/TUESDAY. INITIAL LOOK AT 12Z MODEL DATA CONTINUES TO
INDICATE STRONG OFFSHORE LAX-DAG GRADIENT (-6.7 MB ON THE NAM
TUESDAY MORNING) AND SOME DECENT UPPER LEVEL/THERMAL SUPPORT. SO IT
LOOKS LIKE THE NORTHEAST WINDS WILL REACH MODERATE ADVISORY LEVELS
ACROSS VENTURA/LA COUNTIES. WITH THE MORNING UPDATE...WILL EXTEND
THE ADVISORIES FOR THE VENTURA/LA MOUNTAINS THROUGH 300 PM TUESDAY
AND STRESS A BIT OF A LULL THIS AFTERNOON/EVENING. ALSO...WILL ISSUE
WIND ADVISORIES FOR THE VENTURA VALLEYS/SANTA CLARITA VALLEY/SAN
FERNANDO VALLEY (400 AM TO 300 PM TUESDAY) AND THE COASTAL AREAS OF
VENTURA/LA COUNTIES (700 AM TO 300 PM TUESDAY). DECIDED TO START THE
COASTAL ADVISORIES A BIT LATER AS THERE MAY BE A WEAK MARINE
INVERSION TO COMBAT EARLY TUESDAY MORNING (BASED ON PATCHY STRATUS
CURRENTLY OFFSHORE OF LA).

OTHERWISE...NO MAJOR ISSUES IN THE IMMEDIATE SHORT TERM. WITH
STRONGER OFFSHORE GRADIENTS THIS MORNING...AND WARMER BOUNDARY LAYER
TEMPERATURES...TODAY SHOULD BE NOTICEABLY WARMER WITH MOST COASTAL
AND VALLEY AREAS IN THE LOWER TO MID 70S.

WILL ISSUE AN UPDATE AT 900 AM TO ACCOUNT FOR ADJUSTMENTS WITH WIND
ADVISORIES. OTHERWISE...NO CHANGES ARE PLANNED.

*** LONG TERM FROM PREVIOUS DISCUSSION ***

.LONG TERM (THU-SUN)...
A FAST MOVING INSIDE SLIDER ZIPS THROUGH THE AREA ON CHRISTMAS. IT
WILL BRING PARTLY CLOUDY SKIES TO THE AREA...EXCEPT ON THE NORTH
SLOPES WHERE IT WILL SCOOP UP ENOUGH MOISTURE TO CREATE MOSTLY
CLOUDY SKIES AND A CHANCE OF SOME LIGHT SHOWERS. HGTS FALL AND THE
SFC FLOW WILL SHIFT TO ONSHORE. THESE TWO THINGS WILL COMBINE TO
SHARPLY REDUCE TEMPS AND MOST CSTL AND VLY TEMPS WILL ONLY REACH THE
MID 60S.

A WEEK RIDGE WILL BUILD IN FRIDAY AND SATURDAY AND WILL KEEP THE
WEATHER CLEAR. MAX TEMPS WILL REMAIN A DEGREE OR TWO BLO NORMAL.

ANOTHER INSIDE SLIDER IS ON TAP FOR NEXT SUNDAY WITH SOME MORE
CLOUDS AND COOLER TEMPS.

&&

.AVIATION...22/1140Z

AT 1045Z...THERE WAS NO MARINE LAYER BUT THERE WAS A SURFACE BASED
INVERSION WITH A TOP OF 4400 FEET AND A TEMP OF 20 CELSIUS.

WIDESPREAD MVFR CIGS ACROSS INTERIOR SECTIONS OF SLO AND SBA
COUNTIES AND THE NRN MTN SLOPES THROUGH MID TO LATE MORNING...
WITH LOCAL LIFR CONDS IN LOW CEILINGS AND DENSE FOG. CONDS WILL
IMPROVE BY LATE MORNING OR EARLY AFTERNOON IN MOST AREAS.
OTHERWISE...VFR CONDS EXPECTED THRU THE PERIOD EXCEPT FOR SOME LOCAL
MVFR VSBYS ACROSS COASTAL SECTIONS OF L.A. COUNTY THIS MORNING.

GUSTY NW TO N WINDS IN THE MTNS...ACROSS SRN SBA COUNTY...AND IN
PORTIONS OF THE VLYS OF L.A. AND VTU COUNTIES THROUGH MID
MORNING...WITH WIDESPREAD LLWS AND MDT TO STG UDDFS.

GUSTY NE WINDS EXPECTED TO DEVELOP IN THE MTNS AND VLYS AGAIN LATE
TONIGHT AND CONT TUE MORNING.

KLAX...EXCEPT FOR A 30 PERCENT CHANCE OF MVFR VSBYS THROUGH
16Z...HIGH CONFIDENCE IN VFR CONDS THROUGH THE PD.
THERE IS A 20 TO 30 PERCENT CHANCE OF LLWS AND MDT UDDF THIS
MORNING.

KBUR...HIGH CONFIDENCE IN VFR CONDS THROUGH THE PD. EXPECT LLWS AND
MDT UDDF THIS MORNING.

&&

.MARINE...22/300 AM

GOOD CONFIDENCE THAT GALE FORCE WINDS WILL DIMINISH ACROSS THE OUTER
WATERS THIS AFTERNOON. THERE IS A 20 TO 30 PERCENT CHANCE THAT WINDS
WILL DECREASE BELOW GALE THRESHOLDS THIS MORNING ACROSS NRN
SECTIONS. SMALL CRAFT ADVISORIES FOR WINDS AND/OR SEAS WILL LIKELY
HAVE TO BE ISSUED ONCE THE GALES EXPIRE...AND SHOULD REMAIN IN
EFFECT UNTIL VERY LATE TONIGHT OR TUE MORNING.

GOOD CONFIDENCE THAT WINDS/SEAS WILL DROP BELOW ADVISORY LEVELS
ACROSS THE SBA CHANNEL BY MID MORNING.

THERE IS A 20 PERCENT CHANCE THAT SCA CONDS WILL OCCUR ACROSS THE
NRN INNER WATERS LATE THIS AFTERNOON AND EVENING.

FOR THE INNER WATERS...THERE IS A 30 TO 40 PERCENT CHANCE THAT SMALL
CRAFT ADVISORIES WILL BE NEEDED TUE MORNING FROM VENTURA OR OXNARD
THROUGH SANTA MONICA AND POSSIBLY THROUGH THE SAN PEDRO CHANNEL DUE
TO GUSTY NE WINDS. THERE WILL LIKELY BE SHORT PERIOD CHOPPY SEAS AS
WELL.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...RAT/ASR
AVIATION/MARINE...BRUNO
SYNOPSIS...SETO/RAT

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