Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 221152 AAA
AFDLOX

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

UPDATED AVIATION SECTION

.SYNOPSIS...

HIGH PRESSURE WILL BRING WARMER AND DRY CONDITIONS TO SOUTHERN
CALIFORNIA TODAY THROUGH WEDNESDAY. STRONG NORTHERLY WINDS WILL
AFFECT PARTS OF THE REGION THIS MORNING...THEN NORTHEAST WINDS WILL
AFFECT VENTURA AND LOS ANGELES COUNTIES TONIGHT THROUGH TUESDAY.
SLIGHTLY COOLER CONDITIONS ARE EXPECTED FOR CHRISTMAS DAY INTO THE
WEEKEND.

&&

.SHORT TERM (TODAY-WED)...
A STANDING MTN WAVE BROKE OVER THE MTNS LAST NIGHT ALLOWING HIGH
SPEED WINDS FROM THE MID LEVELS OF THE ATMOSPHERE TO REACH THE SFC.
80 TO 90 MPH GUSTS WERE REPORTED AT SOME MTN RIDGETOP SENSORS. THE
WAVE DISIPATED AROUND 200 AM AND WINDS SUBSIDED TO ADVISORY LEVELS
AND THE HIGH WIND WARNINGS WERE REPLACED BY WIND ADVISORIES WHICH
WILL LAST UNTIL MID MORNING. ASIDE FROM THE WINDS TODAY WILL BE A
NICE DAY WITH SUNNY SKIES AND ABOVE NORMAL TEMPS ACROSS THE COASTS
AND VLYS DUE TO THE OFFSHORE FLOW. AN ASTERISK NEXT TO THE SUNNY
SKIES AS THE PLENTY OF SAN JOAQUIN VLY CLOUDS ARE BUTTED UP AGAINST
THE NORTH SLOPES AND HAVE SPILLED INTO THE INTERIOR SLO VLY AND THE
CUYAMA VLY...THESE CLOUDS WILL DISSIPATE BY NOON.

SURFACE HIGH PRESSURE WILL BUILD INTO THE GREAT BASIN TONIGHT AND
THE PRESSURE GRADIENTS WILL SHIFT TO THE NE. THERE IS STILL A BIT OF
UPPER SUPPORT AND ANOTHER ROUND OF WIND ADVISORIES WILL MORE THAN
LIKELY BE NEEDED. MDLS ARE HINTING AT SOME NE WINDS FOR AVALON
HARBOR TO DEVELOP AFTER MIDNIGHT.

TUESDAY WILL BRING WEATHER THE REST OF THE NATION WILL ENVY. SUNNY
SKIES AND HIGHS IN THE MID 70S TO THE LOWER 80S. BROUGHT TO YOU BY A
THOMPSON RIDGE AND OFFSHORE FLOW. ADVISORY LEVEL WINDS WILL SUBSIDE
LATER IN THE MORNING.

ANOTHER NICE DAY WEDNESDAY IT SHOULD BE VERY SIMILAR TO TUESDAY.
CURRENT FORECAST CALLS FOR SLIGHTLY COOLER MAX TEMPS BUT THIS MAY
NOT BE THE CASE AS TEMPERATURE PARAMETERS LOOK VERY SIMILAR. THE
GRADIENTS DO NOT CHANGE MUCH BUT THE UPPER WIND SUPPORT IS MUCH LESS
SO THE CHC OF ADVISORY LEVEL WINDS SEEMS MINIMAL.

.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...RORKE
AVIATION/MARINE...BRUNO
SYNOPSIS...SETO

WWW.WEATHER.GOV/LOSANGELES








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