203 
FXUS66 KLOX 030303 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
800 PM PDT THU MAY 2 2013

...GUSTY SANTA ANA WINDS AND EXTREME FIRE DANGER WILL CONTINUE 
   THROUGH FRIDAY...

...UPDATED FIRE WEATHER DISCUSSION...

.SYNOPSIS...

A HIGH PRESSURE SYSTEM WITH GUSTY OFFSHORE WINDS WILL CAUSE WELL 
ABOVE NORMAL TEMPERATURES THROUGH FRIDAY. THE HIGH WILL EXIT THE 
REGION LATE FRIDAY AND TEMPERATURES WILL DROP ON SATURDAY. A LOW 
PRESSURE SYSTEM WILL ARRIVE BY SUNDAY WITH POSSIBLE PRECIPITATION 
THROUGH TUESDAY. THE TEMPERATURES WILL BE BELOW NORMAL INTO MIDWEEK.

&&

.SHORT TERM (TODAY-SUN)...THE SMOKE PLUME FROM THE SPRINGS FIRE IN 
CAMARILLO IS EXPECTED TO CONTINUE A WEST NORTHWEST TRAJECTORY 
OVERNIGHT AND POSSIBLY MOVE OVER THE COASTAL WATERS ALONG THE 
CENTRAL COAST. LOW LEVEL CLOUD FIELD APPROACHING THE CENTRAL COAST 
THIS AFTERNOON WILL LIKELY MOVE ASHORE THIS EVENING AND THEN SCOUR 
OUT OR MOVE OFFSHORE OVERNIGHT AS THE NORTHEAST WINDS DEVELOP. THE 
LATE MORNING TEMPERATURES WILL LIKELY BE THE HIGHEST FOR THE DAY 
WITH BEACH LOCATIONS...LIKE PISMO BEACH...POSSIBLY REACHING THE 
LOWER 80S. AND CENTRAL COAST INLAND AREAS WILL LIKELY CLIMB TO 
RECORD HEAT FRIDAY AFTERNOON. PATCHY LOW LEVEL CLOUDS SOUTH OF THE 
NORTHERN CHANNEL ISLANDS WILL CONTINUE TO APPROACH THE LA/VENTURA 
COASTS THROUGH THIS AFTERNOON AND POSSIBLY MOVE INTO THE SANTA 
MONICA BAY WITH DENSE FOG TONIGHT. OTHERWISE THE LATEST HRRR WAS 
CONSISTENT WITH PREVIOUS RUNS AND ONSHORE WINDS WILL MOVE INTO THE 
COASTAL VALLEYS WHILE THE STRONG NORTHEAST WINDS DIMINISH THROUGH 
THE REMAINDER OF THIS AFTERNOON. THE NORTHEAST WINDS WILL LIKELY 
PREVAIL INLAND OVERNIGHT AND AS THE SEABREEZE DISSIPATES THE 
NORTHEAST WINDS WILL RETURN TO THE COAST. THE WINDS MAY STRENGTHEN 
WITH GUSTS TO 45 MPH FRIDAY MORNING OVER THE HIGH COUNTRY WITH LOCAL 
GUSTS TO 35 MPH IN THE INTERIOR COASTAL VALLEYS. A WIND ADVISORY MAY 
BE ISSUED FOR THE HIGH COUNTRY FOLLOWING THE HIGH WIND WARNING 
EXPIRATION AT 6 PM THIS EVENING. A COOLING TREND WILL OCCUR SATURDAY 
THROUGH SUNDAY. ONSHORE WINDS WILL RETURN SATURDAY AND TEMPERATURES 
WILL COOL THOUGH LIKELY REMAIN 5 TO 10 DEGREES ABOVE NORMAL SATURDAY 
AND TO AT OR BELOW NORMAL SUNDAY. AN UPPER LEVEL LOW PRESSURE SYSTEM 
CURRENTLY BETWEEN THE HAWAIIAN ISLANDS AND SOUTHERN CALIFORNIA WILL 
APPROACH THROUGH SUNDAY. LATEST GUIDANCE DIFFERS FROM PREVIOUS RUNS 
AND BETWEEN SUITES THOUGH SKIES WILL LIKELY BECOME CLOUDY AND A 
CHANCE OF SHOWERS ARE EXPECTED SUNDAY.             

.LONG TERM (MON-THU)...A STABLE TYPE PATTERN WITH A ANTICYCLONIC 
CIRCULATION CENTERED OVER THE PAC NW AND CYCLONIC CIRCULATION OVER 
THE SFO BAY AREA WILL DEVELOP SUNDAY AND PERSIST THROUGH WEDNESDAY. 
ONE UPPER LEVEL TROUGH WILL ROTATE AND EXIT THROUGH THE SOLUTION TYPE 
FEATURE SUNDAY THROUGH MONDAY AND A SECOND ONE IS EXPECTED TUESDAY 
NIGHT THROUGH WEDNESDAY. PARTLY TO MOSTLY CLOUDY SKIES ARE EXPECTED 
WITH A SLIGHT CHANCE OF SHOWERS MONDAY THROUGH LATE TUESDAY EVENING. 
TEMPERATURES WILL COOL THROUGH THE PERIOD AND LIKELY RANGE 4 TO 8 
DEGREES BELOW SEASONAL NORMAL THROUGH THE PERIOD.

&&

.FIRE WEATHER...
RED FLAG WARNINGS IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA 
COUNTIES THROUGH FRIDAY AFTERNOON...WHERE EXTREME FIRE DANGER 
EXISTS. AS OF 730 PM...ONSHORE WINDS HAVE SPREAD INTO MUCH OF THE 
LOWER ELEVATIONS OF THE SPRINGS FIRE...HOWEVER CURRENT OBSERVATIONS 
STILL INDICATE OFFSHORE CONDITIONS ACROSS HIGHER RIDGETOPS OF THE 
BURN AREA. FURTHER INLAND...OFFSHORE WINDS AND BONE DRY CONDITIONS 
REMAIN FIRMLY IN TACT...HOWEVER WIND SPEEDS ARE DOWN CONSIDERABLY 
FROM EARLIER TODAY. THIS IS SOME OF THE DRIEST AIR WE HAVE SEEN IN 
QUITE A WHILE ACROSS THE SOUTHLAND...WITH LONG DURATIONS OF SINGLE 
DIGIT HUMIDITIES BEING OBSERVED. IN FACT...A FEW LOCATIONS HAVE 
REPORTED RELATIVE HUMIDITIES AS LOW AS 1 PERCENT TODAY!

BETWEEN 10 AND 11 PM...WINDS ARE EXPECTED TO REVERSE TO AN OFFSHORE
DIRECTION ACROSS MUCH OF THE SPRINGS FIRE BURN AREA. AS OFFSHORE GRADIENTS
TIGHTEN SLIGHTLY OVERNIGHT INTO FRIDAY MORNING...THERE WILL BE A 
SLIGHT INCREASE IN OFFSHORE WINDS. THE SANTA ANA WINDS WILL NOT BE 
AS STRONG AS WE SAW TODAY...HOWEVER GUSTS IN THE 20 TO 30 MPH RANGE 
CAN BE EXPECTED ACROSS THE BURN AREA BETWEEN 4 AM AND NOON FRIDAY...WITH
GUSTS AS HIGH AS 35 MPH AT RIDGETOP LEVEL. AS WINDS REVERSE TO OFFSHORE
LATER TONIGHT...LOOKING FOR HUMIDITIES TO ONCE AGAIN FALL INTO 
SINGLE DIGITS ACROSS THE SPRINGS BURN AREA.

THE OFFSHORE FLOW WILL BRING ANOTHER ROUND OF HOT AND DRY CONDITIONS TO
THE REGION ON FRIDAY...WITH TEMPERATURES SOARING TO BETWEEN 90 AND 100
DEGREES ALONG WITH LONG DURATIONS OF SINGLE DIGIT HUMIDITIES. WINDS
ARE EXPECTED TO REVERSE TO ONSHORE EARLIER ON FRIDAY...MOST LIKELY
BETWEEN 1 AND 2 PM ACROSS THE SPRINGS BURN AREA. THE ONSHORE WINDS WILL
ALSO SPREAD FURTHER INLAND ACROSS MOST VALLEY AREAS LATER FRIDAY 
AFTERNOON. 

THE COMBINATION OF GUSTY OFFSHORE WINDS...LOW HUMIDITIES AND VERY 
DRY FUELS HAS CREATED THE POTENTIAL FOR EXTREME FIRE BEHAVIOR. IT IS 
IMPORTANT TO NOTE THAT FUEL CONDITIONS ARE EXTREMELY DRY FOR THIS 
TIME OF THE YEAR...WITH VALUES THAT ARE MORE TYPICAL FOR JULY OR 
AUGUST.

&&

.AVIATION...02/2350Z...GENERALLY HI CONFIDENCE IN THE CURRENT TAFS 
WITH VFR CONDITIONS AT ALMOST ALL AIRFIELDS THROUGH FRI. EXCEPTION 
IS KSMX WHERE THERE IS A 70 PERCENT CHANCE LOW CLOUDS AND IFR 
CONDITIONS SHOULD MOVE INTO THE AIRFIELD BY 05Z THEN CLEAR TO VFR BY 
12Z. THERE IS ALSO A 30 PERCENT CHANCE LIFR CONDITIONS COULD AFFECT 
KSMX AT TIMES DURING THE PERIOD. GUSTY E WINDS AT KWJF AND KPMD WILL 
DIMINISH EARLY THIS EVENING.

KLAX...HI CONFIDENCE IN THE CURRENT TAF WITH VFR CONDITIONS THRU FRI 
EVENING.

KBUR...HI CONFIDENCE IN THE CURRENT TAF WITH VFR CONDITIONS THRU FRI.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING (SEE LAXRFWLOX).
WIND ADVISORY (SEE LAXNPWLOX).

&&

$$

PUBLIC...30
AVIATION...SIRARD
SYNOPSIS...SETO
FIRE...GOMBERG

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