Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 211201
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
326 AM PST SUN DEC 21 2014

.SYNOPSIS...
SKIES WILL BE PARTLY TO MOSTLY CLOUDY TODAY. A FEW SHOWERS ARE
POSSIBLE ON NORTHERN MOUNTAIN SLOPES. HIGH PRESSURE ALOFT WILL
BRINGING WARM AND DRY CONDITIONS TO SOUTHERN CALIFORNIA MONDAY
THROUGH WEDNESDAY. GUSTY NORTHWEST TO NORTH WINDS WILL AFFECT PARTS
OF THE REGION THROUGH TONIGHT...THEN GUSTY NORTHEAST WINDS WILL
AFFECT VENTURA AND LOS ANGELES COUNTIES MONDAY THROUGH TUESDAY.
COOLER CONDITIONS ARE EXPECTED FOR CHRISTMAS DAY INTO NEXT WEEKEND.

&&

.SHORT TERM (TODAY-TUE)...LOTS OF HIGH LEVEL CLOUDINESS STREAMING
SWD ACROSS THE REGION THIS MORNING. SOME LOW CLOUDS HAVE DEVELOPED
ACROSS COASTAL SECTIONS OF L.A. COUNTY...AND ACROSS INTERIOR
SECTIONS OF SLO COUNTY. MOIST UPSLOPE NLY FLOW PILING UP ON THE
NORTHERN MTN SLOPES OF VTU COUNTY AND NWRN LOS ANGELES COUNTY WILL
LIKELY KEEP SKIES MOSTLY CLOUDY THERE TODAY...AND THERE COULD BE A
FEW LIGHT SHOWERS AS WELL. ELSEWHERE...WILL GO WITH A PARTLY CLOUDY
OR PARTLY TO MOSTLY CLOUDY FORECAST...AS THE HIGH CLOUDINESS WILL
LIKELY BE THICK ENOUGH TO BLOCK OUT THE SUN AT TIMES. GUSTY NW TO N
WINDS CONTD ACROSS THE INTERSTATE 5 CORRIDOR...AND THROUGH AND BELOW
PASSES AND CANYONS OF THE SANTA YNEZ RANGE. WINDS MAY DECREASE FOR A
WHILE LATER THIS MORNING INTO THE AFTERNOON...BUT MODELS SHOW
ANOTHER BURST OF STRONG NLY WINDS FROM 850 TO 950 MB THIS EVENING
THROUGH EARLY MONDAY MORNING...WITH SOME DECENT SUBSIDENCE. WIND
ADVISORIES ARE IN EFFECT FOR THESE AREAS THROUGH MID MORNING MONDAY.
HAVE EXPANDED WIND ADVISORIES TO INCLUDE THE SANTA MONICA MOUNTAINS
SINCE GUSTY WINDS HAVE SURFACE THERE AS WELL. EXPECT SOME GUSTY
WINDS TO AFFECT THE SANTA CLARITA...SAN FERNANDO AND ERN VTU COUNTY
VALLEYS THIS MORNING...BUT EXPECT WINDS TO REMAIN BELOW ADVISORY
LEVELS (ALTHOUGH IT MAY GET CLOSE IN THE SANTA CLARITA VALLEY).
WITH RISING HEIGHTS/THICKNESSES AND WARMING AT 850 AND 950
MB...EXPECT SEVERAL DEGREES OF WARMING IN MOST AREAS
TODAY...ALTHOUGH THE CLOUD SHIELD MAY KNOCK A FEW DEGREES OFF
MAX TEMP POTENTIAL.

A STRONG UPPER HIGH IN THE ERN PACIFIC WILL CONTINUE TO EDGE INTO
THE REGION TONIGHT AND MONDAY...CAUSING HEIGHTS AND THICKNESSES TO
CONTINUE TO RISE. LOW LEVEL FLOW WILL TURN MORE NELY BY EARLY MONDAY
MORNING...WHICH SHOULD CAUSE WINDS TO DIMINISH ACROSS SBA COUNTY AND
THE I-5 CORRIDOR. HOWEVER...AREAS OF L.A. AND VTU COUNTIES PRONE TO
NE WINDS WILL LIKELY HAVE GUSTY WINDS MONDAY...ALTHOUGH PROBABLY A
BIT BELOW ADVISORY TEMPS. MAX TEMPS WILL LIKELY BE UP SEVERAL MORE
DEGREES ON MONDAY.

OFFSHORE W-E GRADIENTS WILL INCREASE MON NIGHT/TUE...AND THE LATEST
MODELS...WITH A TROUGH IN THE ROCKIES NOW DIGGING A BIT FARTHER
WESTWARD...SHOW MORE IN THE WAY OF SUPPORT FOR GUSTY NE WINDS ACROSS
L.A. AND VTU COUNTIES MON NIGHT/TUE. AT THIS POINT...IT APPEARS THAT
WIND ADVISORIES WILL BE NEEDED FOR PORTIONS OF L.A./VTU COUNTIES.
THE LATEST MODELS ALSO SHOW SOME HEIGHT/THICKNESS FALLS AND SOME
COOLING AT 850 MB AND 950 MB. THIS MAY ACTUALLY BRING SOME SLIGHT
COOLING EVEN TO AREAS W OF THE MTNS ON TUE. HAVE KNOCKED A FEW
DEGREES OFF OF MAX TEMPS FOR TUE...ESPECIALLY IN THE VLYS.

.LONG TERM (WED-SAT)...THE UPPER HIGH TO THE SW OF THE REGION WILL
HOLD INTO WED...ALTHOUGH IT WILL BEGIN TO WEAK. OFFSHORE FLOW AND
SOME LOCALLY GUSTY WINDS IN THE MORNING WILL TURN ONSHORE IN THE
AFTERNOON. MAX TEMPS MAY BE DOWN A COUPLE OF DEGREES ON
WED...ESPECIALLY NEAR THE COAST. A TROUGH WILL ZIP THROUGH THE PAC
NW LATE WED INTO THU...CAUSING DECENT HEIGHT FALLS ACROSS THE
REGION...AND INCREASING ONSHORE FLOW. EXPECT MAX TEMPS TO BE DOWN
SEVERAL DEGREES ON THU...DOWN TO NEAR OR POSSIBLY SLIGHTLY BELOW
NORMAL LEVELS. ANY RAIN WILL REMAIN FAR TO THE NORTH OF THE AREA. AS
THE TROUGH MOVES QUICKLY EWD...HEIGHTS WILL SLOWLY RISE OVER THE
FCST AREA FRI AND SAT...SO EXPECT A GRADUAL WARMING TREND.

&&

21/1200Z

AT 1000Z AT KLAX THERE WAS NO MARINE LAYER OR INVERSION.

GOOD CONFIDENCE IN MOST TAFS. THERE IS A 30 PERCENT CHC OF IFR CIGS
THIS MORNING AT KLAX...KSMX AND KSBP THROUGH 17Z. LLWS AND
TURBULENCE IS LIKELY AGAIN AT KSBA AFTER 02Z.

KLAX...FAIR CONFIDENCE IN TAF. THERE IS A 30 PERCENT CHANCE OF IFR
CIGS THROUGH 17Z. THERE IS A 10 PERCENT CHANCE OF AN EAST WIND
COMPONENT OF 8 KT.

KBUR...GOOD CONFIDENCE IN TAF.

&&

.MARINE...

21/330 AM

GOOD CONFIDENCE IN COASTAL FORECAST WITH LONG PERIOD LARGE SWELL
MOVING THROUGH WATERS. GOOD CONFIDENCE IN SMALL CRAFT ADVISORY WINDS
INCREASING TO GALE FORCE LATER TODAY FROM NORTH OF SAN NICOLAS
ISLAND TO POINT SAL. SMALL CRAFT ADVISORY WINDS WILL LIKELY PERSIST
UNTIL TUESDAY FOR MOST OF THE OUTER WATERS.

&&

.BEACHES...

21/330 AM.

A LARGE SWELL WITH A DIRECTION OF 290-300 DEGREES AND A LONG PERIOD
(18 SECONDS) GENERATED BY A DISTANT STORM IN THE GULF OF ALASKA WILL
CONTINUE TO BRING VERY HIGH SURF TO AREA BEACHES TODAY. THE SURF
WILL NOT BE A HIGH AS IT WAS SATURDAY AND THE SURF ACROSS THE LA
BEACHES WILL BE JUST BELOW HIGH SURF CRITERIA. THE SURF AND SWELL
WILL SLOWLY SUBSIDE THROUGH THE DAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
FLOOD ADVISORY (SEE LAXFLSLOX).
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...ASR


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