Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 041013
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
300 AM PDT MON MAY 4 2015

.SYNOPSIS...

NIGHT THROUGH MORNING LOW CLOUDS AND FOG WILL CONTINUE FOR THE COAST
AND VALLEYS THROUGH MIDWEEK WITH ONSHORE FLOW AND WEAK LOW PRESSURE.
ANOTHER LOW WILL MOVE IN THURSDAY AND FRIDAY WITH POSSIBLE RAIN
SHOWERS. TEMPERATURES SHOULD REMAIN BELOW NORMAL THROUGH THE WEEK.
FOR NEXT WEEKEND...HIGH PRESSURE WILL BRING FAIR AND WARMER
CONDITIONS TO THE AREA.

&&

.SHORT TERM (TODAY-WED)...
2400 FOOT MARINE CAPPED BY A WEAK INVERSION. MODERATE ONSHORE
GRADIENTS BOTH TO THE NORTH AND THE EAST. UNFORTUNATELY THERE IS NO
EDDY TO PROVIDE NEEDED THE NEEDED WEAK LIFT TO CREATE THE LOW
CLOUDS. THUS LOW CLOUDS WILL FORM RATHER HAPHAZARDLY AND SLOWLY.
CURRENT FORECAST HAS EXTENSIVE CLOUD COVER AND WHILE IT IS LIKELY
THAT THE CLOUD FIELD WILL FILL IN BY DAWN IT IS BY NO MEANS CERTAIN.
THE DEEP MARINE LAYER MAY WELL COOK UP INTO A STRATA CU DECK THIS
AFTERNOON BRINGING PARTLY CLOUDY SKIES TO SOME AREAS. THERE IS
ENOUGH INSTABILITY DUE TO THE COOL AIR ALOFT ASSOC WITH A WEAK UPPER
LOW PASSING TO THE SOUTH THIS AFTERNOON TO CREATE SOME MTN CLOUDS
THIS AFTERNOON. NOT TOO WORRIED ABOUT SHOWERS DUE TO THE VERY DRY
CONDITIONS BUT ON THE FAR EASTERN SECTION OF THE SAN GABRIELS THERE
IS ENOUGH TO WARRANT A 20 PERCENT CHC. STRONG ONSHORE FLOW TO THE
EAST THIS AFTERNOON WILL MAKE FOR BREEZY CONDITIONS WITH JUST BELOW
WIND ADVISORY LEVEL WINDS LIKELY IN THE ANTELOPE VLY. LOWER HGTS AND
A STRONG SEA BREEZE WILL KEEP ALL MAX TEMPS BELOW NORMAL.

BROAD TROFING AND ONSHORE FLOW WILL PERSIST THROUGH WEDNESDAY.
CLOUDS WILL SLOWLY DEVELOP EACH NIGHT AND BY DAWN SHOULD COVER MOST
OF THE COASTS AND VLYS. MAX TEMPS WILL CONTINUE 4 TO 8 DEGREES BLO
NORMAL AND WILL NOT CHANGE MUCH DAY TO DAY.

.LONG TERM (THU-SUN)...
INTERESTING WEATHER ON TAP FOR THU AND FRI AS A COLD FOR MID MAY LOW
PRESSURE SYSTEMS MOVES OUT OF OREGON AND INTO CALIFORNIA. MDLS WERE
FOR A WHILE HOLDING THE SYSTEM MORE TO THE WEST WHICH WOULD BE BEST
FOR SHOWER ACTIVITY NOW THEY ARE FORECASTING A DRIER EASTWARD TRACK
THAT REALLY ONLY FAVORS L.A. COUNTY. BIASED THE RAIN CHC TOWARDS LA
COUNTY. THERE WILL BE ENOUGH LIFT IN THE AREA THU MORNING TO CREATE
SOME DRIZZLE. EVEN IF IT DOES RAIN IT WILL NOT RAIN MUCH. WILL HOLD
OFF ON TSTMS UNTIL THERE IS BETTER CONFIDENCE ON THE EXACT TRACK OF
THE LOW. HGTS ARE FCST TO FALL TO 560 DM OR 20 DM BLO NORMAL MAX
TEMPS WILL BE BELOW NORMAL ACROSS THE BOARD 3 TO 6 DEGREES BLO
NORMAL ACROSS THE COASTS AND 8 TO 16 DEGREES BLO NORMAL FOR THE VLYS
AND DESERT AREAS.

THE LOW WILL KICK OUT FRIDAY NIGHT AND HIGH PRESSURE SHOULD BUILD IN
FOR SUNNIER DAYS AND WARMER TEMPS WITH SLIGHTLY ABOVE NORMAL TEMPS
ON SUNDAY.

&&

.AVIATION...

04/06Z.

AT 0510Z AT KLAX...THE INVERSION WAS BASED AT 650 FEET WITH THE TOP
AT 3000 FEET AND A TEMPERATURE OF 17 DEGREES CELSIUS.

OVERALL...LOW TO MODERATE CONFIDENCE IN THE 06Z TAFS. THE LOWER
CONFIDENCE IS MOSTLY DUE TO THE UNCERTAINTY IN THE ARRIVAL TIME OF
IFR/MVFR CONDITIONS. IFR TO MVFR CONDITIONS AT COASTAL SITES ARE
MOST LIKELY TO ARRIVE BY 10Z THEN SPREAD INTO VALLEY SITES. IFR/MVFR
CONDITIONS WILL RETURN A BIT EARLIER TOMORROW NIGHT BUT THERE IS A
40 PERCENT CHANCE OF LITTLE TO NO CLEARING AT ALL COASTAL AND VALLEY
TERMINALS.  ELSEWHERE... VFR CONDITIONS WILL PREVAIL THROUGHOUT THE
FORECAST PERIOD.

KLAX...LOW TO MODERATE CONFIDENCE IN THE 06Z TAF. THE LOWER
CONFIDENCE IS MOSTLY DUE TO THE UNCERTAINTY IN THE ARRIVAL TIME OF
IFR/MVFR CONDITIONS. IFR TO MVFR CONDITIONS ARE MOST LIKELY TO
ARRIVE BY 10Z AND WILL LINGER INTO THE AFTERNOON. THEY WILL RETURN A
BIT EARLIER TOMORROW NIGHT BUT THERE IS A 40 PERCENT CHANCE OF
LITTLE TO NO CLEARING AT ALL.

KBUR...LOW TO MODERATE CONFIDENCE IN THE 06Z TAF. THE LOWER
CONFIDENCE IS MOSTLY DUE TO THE UNCERTAINTY IN THE ARRIVAL TIME OF
IFR/MVFR CONDITIONS. IFR TO MVFR CONDITIONS ARE MOST LIKELY TO
ARRIVE BY 12Z. THEY WILL RETURN A BIT EARLIER TOMORROW NIGHT BUT
THERE IS A 40 PERCENT CHANCE OF LINGERING INTO THE AFTERNOON HOURS
AND A TEN PERCENT CHANCE OF LITTLE TO NO CLEARING AT ALL.

&&

.MARINE...

04/300 AM

FOR THE OUTER WATERS...NORTHWEST WINDS WILL FLIRT WITH SMALL CRAFT
ADVISORY LEVELS TODAY AND THERE IS A GOOD CHANCE THAT AN ADVISORY
WILL BE NEEDED FOR THE CENTRAL AND SOUTHERN OUTER ZONES BY THIS
AFTERNOON.  THE NORTHWEST WINDS WILL INCREASE ON TUESDAY AND SMALL
CRAFT ADVISORY CONDITIONS WILL LIKELY DEVELOP ACROSS THE OUTER
WATERS AND CONTINUE THROUGH THURSDAY.

FOR THE INNER WATERS...MODERATE TO HIGH CONFIDENCE IN WEST TO
NORTHWEST WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS THOUGH
WITH PERIODIC ADVISORY LEVEL CONDITIONS ACROSS THE WESTERN HALF OF
THE SANTA BARBARA CHANNEL TUESDAY THROUGH THURSDAY.

A LONG PERIOD (20-24 SECOND) SOUTHERLY SWELL WILL MOVE INTO THE
COASTAL WATERS TODAY...AND REMAIN THROUGH EARLY THIS WEEK.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY (SEE LAXCFWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...RORKE
AVIATION/MARINE...KJ
SYNOPSIS...SIRARD

WWW.WEATHER.GOV/LOSANGELES





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