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494
FXUS66 KLOX 250028 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
530 PM PDT THU APR 24 2014

...UPDATE FOR NEW AVIATION DISCUSSION...

.SYNOPSIS...

A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE AREA WITH BREEZY
WINDS...A DROP IN TEMPERATURES AND SHOWERS ACROSS THE AREA FRIDAY
NIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL BEGIN TO TAKE HOLD
SUNDAY AND EARLY NEXT WEEK...BRINGING UNSEASONABLY WARM TEMPERATURES
FOR MOST OF THE WEEK.

&&

.SHORT TERM (FRI-SUN)...
ONE MORE DAY OF CLEAR SKIES AND TEMPERATURES JUST ABOVE NORMAL TODAY
BEFORE A STRONG UPPER LEVEL TROUGH QUICKLY SWEEPS THROUGH THE AREA
FRIDAY NIGHT AND SATURDAY MORNING...BRINGING BREEZY
CONDITIONS...SHOWERS...AND COOLER TEMPERATURES. FORECAST ISSUES
PRIOR TO TOMORROW NIGHT WILL BE WINDS ALONG THE LOWER ELEVATIONS OF
THE SANTA YNEZ RANGE AND SANTA BARBARA SOUTH COAST THIS EVENING AND
LATER TONIGHT...THEN LOW CLOUDS AND FOG DEVELOPING IN MOST COASTAL
AREAS...THE EXCEPTION BEING THE SANTA BARBARA COAST. NORTHWEST WINDS
IN THE LOWER LEE SIDE ELEVATIONS OF THE SANTA YNEZ AND FOR THE SANTA
BARBARA SOUTH COAST WILL NOT BE AS STRONG AS THE 50 MPH PLUS WINDS
RECORDED IN THE MONTECITO HILLS LAST NIGHT...BUT WILL STILL BE AT
LEAST LOW END ADVISORY LEVEL. EXPECT THE STRONGER WINDS TO BE MORE
TOWARD THE GAVIOTA PASS AREA...THEN INCREASING FURTHER EAST TOWARD
MONTECITO LATER IN THE EVENING. A STRONG EDDY WILL DEVELOP TONIGHT
TO HELP USHER IN LOW CLOUDS AND FOG FOR THE LOS ANGELES AND VENTURA
COUNTY COASTAL AREAS...AND LIKELY PENETRATING INTO THE VALLEYS.

FRIDAY WILL BE CLOUDY AND COOLER AS FRIDAY NIGHT`S TROUGH APPROACHES
FROM OUR NORTHWEST. MODELS DO NOT DIFFER MUCH AS FAR AS THE SPEED
AND INTENSITY OF THE TROUGH AS IT MOVES THROUGH FRIDAY NIGHT. MODELS
APPEAR TO BE NOW TRENDING FASTER WITH THIS SYSTEM...PUTTING THE
WINDOW OF PRECIPITATION MORE IN THE 00Z-06Z TIME FRAME. HOWEVER
THERE IS SOME DIFFERENCE IN FORECAST PRECIPITATION AMOUNTS. AFTER
BEING ONE OF THE DRIER SOLUTIONS...THE GFS IS NOW THE WETTEST. THE
ECMWF IS DRIER...AND THE NAM DRIER STILL. THE GFS AMOUNTS ARE
CERTAINLY JUSTIFIABLE GIVEN THE DYNAMIC FORCING IN THE GFS ALONG
WITH ENOUGH MOISTURE TO PRODUCE THE HIGHEST AMOUNTS AMONG THE
MODELS. HAVE DECIDED TO AT LEAST TREND WETTER IN THE
FORECAST...ALTHOUGH NOT AS WET AS THE GFS...AND ALSO INCREASED
PRECIPITATION PROBABILITIES FOR THE 00Z-12Z SATURDAY TIME
PERIOD...FOCUSING ON THE 00Z-06Z SATURDAY TIME. STORM TOTALS FOR NOW
ARE EXPECTED TO RUN IN THE QUARTER TO ISOLATED HALF INCH RANGE IN
THE MOUNTAINS AND LESSER AMOUNTS ELSEWHERE. WITH THE PATH OF THIS
SYSTEM AND ITS PREDOMINANCE FOR WEST TO NORTHWESTERLY FLOW AND
LITTLE OR NO SOUTHERLY WIND COMPONENT...IT WILL BE DIFFICULT TO
SQUEEZE MUCH PRECIPITATION OUT FOR COASTAL AREAS AND AREAS LIKE THE
FOOTHILLS OF THE SAN GABRIELS...SO GENERALLY EXPECT A TENTH OR LESS.
THOSE AREAS. THE ONE EXCEPTION MIGHT BE CENTRAL SLO COUNTY COAST.
SNOW LEVELS WILL DROP ON FRIDAY NIGHT TO BETWEEN 5000 AND 5500
FEET...BUT DO NOT EXPECT MUCH SNOW ACCUMULATION.

WINDS WILL BE AN ISSUE FROM FRIDAY AFTERNOON ACROSS THE ANTELOPE
VALLEY...THEN AS THE TROUGH QUICKLY MOVES THROUGH FRIDAY NIGHT WE
SHOULD SEE AT LEAST ADVISORY AND MAYBE STRONGER WINDS OVER THE
ANTELOPE VALLEY AND AREAS AROUND AND IN THE GRAPEVINE. WILL NEED AT
LEAST ADVISORIES FOR THESE AREAS FOR FRIDAY NIGHT...AND MAY HAVE TO
CONSIDER SOMETHING STRONGER FOR SATURDAY MORNING. MAY EVEN NEED
ADVISORIES COASTAL AREAS ON SATURDAY.

THE SYSTEM QUICKLY MOVES EAST ON SATURDAY. EXPECT JUST STRAY SHOWERS
LEFT BEHIND ON SATURDAY MORNING EASTERN PORTIONS BEFORE PRECIP
CHANCES ARE ALL BUT FINISHED ON SATURDAY AFTERNOON. TEMPERATURES
WILL REMAIN COOL ON SATURDAY WITH HIGHS ONLY REACHING INTO THE 60S
LOWER ELEVATIONS AND THE 40S HIGHER ELEVATIONS...WHICH IS A GOOD
10-15 DEGREES BELOW NORMAL.

SUNDAY BEGINS OUR WARMUP AS THE UPPER RIDGE BUILDS OVER THE EASTERN
PACIFIC. TEMPERATURES WILL WARM 5-10 DEGREES ACROSS THE AREA...BUT
STILL REMAIN 5-10 DEGREES BELOW NORMAL. MODELS SHOW SOME MID AND
HIGH LEVEL MOISTURE AROUND SO EXPECT SOME CLOUDS.

.LONG TERM (MON-THU)...
A SIGNIFICANT WARM UP IS STILL ON TRACK FOR MOST OF NEXT WEEK. DOES
NOT LOOK LIKE IT WILL BE AS WARM AS PREVIOUSLY THOUGHT WITH 950
TEMPERATURES NOW STAYING UNDER 30 DEG C AS WAS PREVIOUSLY FORECAST
BY THE GFS...BUT DOES LOOK LIKE IT WILL NOW LAST A LITTLE LONGER.
HIGH TEMPERATURES WILL WARM EACH DAY STARTING MONDAY AND
TUESDAY...THEN LEVEL OFF SLIGHTLY ON WEDNESDAY AND COOL JUST A BIT
MORE ON THURSDAY. TOUGH TO TELL IF TUESDAY OR WEDNESDAY WILL BE THE
WARMEST DAY AT THIS POINT...BUT EXPECTING HIGHS IN UPPER 80S AND LOW
90S COAST AND VALLEYS BY TUESDAY AND WEDNESDAY...AND EVEN WITH A
COUPLE OF DEGREES COOLING ON THURSDAY WE SHOULD CONTINUE TO REPORT
SOME LOW 90 DEGREE READINGS ON THURSDAY IN THE VALLEYS.  THIS IS 15
TO 20 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. OFFSHORE WINDS
WILL BE STRONGEST ON WEDNESDAY AND WEAKEN SOME ON THURSDAY. THESE
HEAT EVENTS TEND TO LAST A LITTLE LONGER THAN MODELS FORECAST AND
OFTENTIMES SOME OF THE WARMEST DAYS OF THE EVENT ARE WHEN THE
OFFSHORE WINDS WEAKEN ON THE TAIL END OF IT.

&&

.AVIATION...25/0025Z...MODERATE CONFIDENCE OVERALL IN THE 00Z TAFS.
THERE IS HI CONFIDENCE IN VFR CONDITIONS THRU FRI FOR KPRB...KSBP...
KWJF AND KPMD. FOR KSMX...THERE IS MODERATE CONFIDENCE IN ANY LOW
CLOUDS AND IFR CIGS DEVELOPING LATE TONIGHT INTO FRI MORNING. FOR
KSBA...LOW CLOUDS AND MVFR CONDITIONS ARE FORECAST TO DEVELOP BY 17Z
FRI AND PERSIST THRU ABOUT 23Z FRI...BUT THERE ARE UNCERTAINTIES
WITH THE TIMING OF ANY DEVELOPMENT WHICH MAY BE OFF PLUS/MINUS AN
HOUR OR SO. THERE IS ALSO A QUESTION OF WHETHER LOW CLOUDS WILL
IMPACT THE AIRFIELD AT ALL. AT KOXR...KLAX...KLGB...KBUR AND KVNY...
THERE IS MODERATE CONFIDENCE IN THE TIMING OF THE DEVELOPMENT OF LOW
CLOUDS AND MVFR CIGS LATE TONIGHT WHICH COULD BE OFF PLUS/MINUS AN
HOUR OR TWO. LOW LEVEL WIND SHEAR MAY BE POSSIBLE AT KSBA THIS
EVENING DUE TO GUSTY N CANYON WINDS IN THE VICINITY. GUSTY WINDS AT
KPMD AND KWJF THIS EVENING WILL DIMINISH SOME TONIGHT THEN BECOME
STRONG AND GUSTY BY FRI AFTERNOON WITH A SLIGHT CHANCE OF REDUCED
VSBYS IN BLOWING DUST AT TIMES.

KLAX...MODERATE CONFIDENCE OVERALL IN THE 00Z TAF. THERE ARE
UNCERTAINTIES IN THE TIMING OF THE DEVELOPMENT OF LOW CLOUDS AND
MVFR CIGS LATE TONIGHT WHICH COULD BE OFF AN HOUR OR TWO ESPECIALLY
TOO EARLY. ONCE THE LOW CLOUDS DEVELOP...THEY SHOULD PERSIST THRU
EARLY FRI EVENING.

KBUR...MODERATE CONFIDENCE OVERALL IN THE 00Z TAF. THERE ARE
UNCERTAINTIES IN THE TIMING OF THE DEVELOPMENT OF LOW CLOUDS AND
MVFR CIGS LATE TONIGHT WHICH COULD BE OFF AN HOUR OR TWO ESPECIALLY
TOO EARLY. ONCE THE LOW CLOUDS DEVELOP...THEY SHOULD PERSIST THRU
ABOUT 20Z FRI WITH VFR CONDITIONS THE REST OF THE AFTERNOON.

&&

.MARINE...24/300 PM PDT...

SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ZONES PZ650...VALID 3PM
THIS AFTERNOON THROUGH 9 PM THIS EVENING...PZ645...VALID 3PM THIS
AFTERNOON THROUGH 9PM THIS EVENING...AND PZ670...THROUGH 3 AM FRIDAY.

GALE WARNING REMAINS IN EFFECT FOR ZONES PZ673...PZ676 VALID 3PM
TODAY THROUGH 3AM FRIDAY.

GALE WATCH REMAINS IN EFFECT FOR OUTER WATERS ZONES PZ673...PZ676
AND FOR INNER WATER ZONES PZ650...PZ655 VALID FRIDAY AFTERNOON
THROUGH LATE SATURDAY NIGHT.

A 1025 MB HIGH WAS 800 NM SW OF POINT CONCEPTION...AND A 1016 MB
HIGH WAS OVER NORTHERN NEVADA. ACROSS THE COASTAL WATERS...MODERATE
TO LOCALLY STRONG GALE FORCE W TO NW WINDS WILL CONTINUE THROUGH
TONIGHT. STRONGER W TO NW WINDS ARE EXPECTED TO SPREAD ACROSS THE
WATERS FRI NIGHT INTO SATURDAY. THERE IS SOME UNCERTAINTY ABOUT THE
ONSET OF GALE FORCE WINDS SOUTH OF POINT CONCEPTION WITH THE
POSSIBILITY THAT THE STRONGEST WINDS WILL HOLD OFF UNTIL LATER
FRIDAY NIGHT AFTER THE PASSAGE OF A FAST MOVING COLD FRONT.


&&

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

&&
$$

PUBLIC...JACKSON
AVIATION...SIRARD
MARINE...SWEET
SYNOPSIS...KJ

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