Weather Service Report


558 
FXUS66 KLOX 012021
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
120 PM PDT WED OCT 1 2014

.SYNOPSIS...

A SIGNIFICANT WARMING TREND IS EXPECTED INTO THE WEEKEND AS SURFACE 
HIGH PRESSURE BUILDS INTO THE GREAT BASIN AND OFFSHORE FLOW 
STRENGTHENS THROUGH LATE THIS WEEK. WEAKER OFFSHORE FLOW IS EXPECTED 
FOR THE WEEKEND...BUT HOT AND DRY WEATHER WILL CONTINUE AS HIGH 
PRESSURE BUILDS ALOFT. COOLER WEATHER IS POSSIBLE EARLY TO MID NEXT 
WEEK.

&&

.SHORT TERM (TODAY-SAT)...INTERIOR AREAS AND CENTRAL COAST SEEING 
THE INITIAL SHOT OF SANTA ANA WINDS TODAY, PRETTY MUCH RIGHT ON 
SCHEDULE. WINDS WILL DO THEIR USUAL DIURNAL SHIFT AND WEAKEN DURING 
THE AFTERNOON AND EVENING BEFORE RETURNING WITH THE MAIN OFFSHORE 
PUSH OVERNIGHT AND EARLY THU WHICH WILL BRING WINDS DOWN TO COAST 
AND VALLEY AREAS (EXCEPT LA COAST). BECAUSE IT'S PRIMARILY GRADIENT 
DRIVEN IT'S STILL LOOKING LIKE A LOW GRADE SANTA ANA WIND EVENT AT 
BEST WITH SOME ISOLATED GUSTS IN THE MID 40S IN THE FAVORED (AND 
GENERALLY UNPOPULATED) AREAS WHILE MOST AREAS SEE SUB-ADVISORY LEVEL 
WINDS IN THE 30S OR LESS. ON FRIDAY WINDS ARE EXPECTED TO BE ABOUT 
10 MPH LESS THAN THU BUT STILL BREEZY IN THE USUAL SPOTS.

TEMPERATURES EXPECTED TO JUMP SEVERAL DEGREES THU WITH HIGHS IN THE 
80S AND 90S, THEN ANOTHER 3-6 DEGREES FRI. COASTAL AREAS WILL 
PROBABLY SEE BIGGEST WARMUP THU WHILE ON FRIDAY THE BIGGER JUMP WILL 
BE THE INTERIOR AS COLD AIR FROM THE PASSING TROF EXITS THE AREA.

SAT STILL EXPECTED TO BE THE WARMEST DAY. OFFSHORE WINDS SHOULD BE 
FAIRLY LIGHT AS GRADIENTS WEAKEN. 

HIGHS THROUGH SATURDAY WILL THREATEN DAILY RECORDS BUT MOST 
LOCATIONS WILL PROBABLY FALL JUST A LITTLE SHORT. SANTA MARIA'S 
RECORD OF 96 THU MAY BE THE EXCEPTION. HEAT INDEX LEVELS ARE NOT 
EXPECTED TO REACH OUR WARNING THRESHOLD OF 105 BECAUSE WIDESPREAD 
HUMIDITIES UNDER 10% RESULTS IN HEAT INDEX VALUES ABOUT 5-7 DEGREES 
BELOW THE AMBIENT AIR TEMPERATURE.

.LONG TERM (SUN-WED)...COOLING TREND TO BEGIN SUNDAY AS GRADIENTS 
START TURNING ONSHORE. HOWEVER, IT WILL STILL BE SEVERAL DEGREES 
ABOVE NORMAL. NORMAL TEMPS EXPECTED TO RETURN BY AROUND WEDNESDAY. 
SKIES EXPECTED TO REMAIN CLEAR, EXCEPT FOR SOME COASTAL MARINE LYR 
CLOUDS RETURNING MONDAY OR TUESDAY. 

&&

.AVIATION...01/1800Z.
GOOD CONFIDENCE IN THE 18Z TAFS. INCREASING OFFSHORE FLOW IN THE 
NEXT 24 HOURS SHOULD KEEP ANY MARINE CLOUDS AT BAY AND INSURE VFR 
CONDITIONS THROUGH THURSDAY.

KLAX...GOOD CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT CHANCE 
OF IFR CONDITIONS WITH A SURPRISE PATCH OF MARINE CLOUDS LATE 
TONIGHT AND EARLY THURSDAY MORNING.

KBUR...HIGH CONFIDENCE IN THE 18Z TAF. 

&&

.MARINE...01/200 PM...

FOR THE OUTER WATERS...FOR TONIGHT AND THROUGH THE WEEKEND...WINDS 
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS.  

FOR THE INNER WATERS...HIGH CONFIDENCE IN WINDS REMAINING BELOW 
ADVISORY LEVELS THROUGH THIS EVENING. BY LATE TONIGHT AND THURSDAY 
HIGH CONFIDENCE IN NORTHEAST WINDS DEVELOPING WITH A CHANCE OF WINDS 
REACHING SMALL CRAFT ADVISORY THRESHOLDS THURSDAY MORNING 
(ESPECIALLY NEAR SHORE) FROM VENTURA TO MALIBU AND OUT TO THE 
ISLANDS. FOR FRIDAY THROUGH THE WEEKEND...WEAK OFFSHORE FLOW CAN BE 
EXPECTED AT NIGHT...AND WEAK ONSHORE FLOW IN THE AFTERNOON/EVENING 
HOURS.

A LONG PERIOD SOUTH-SOUTHWEST SWELL IS ANTICIPATED TO ARRIVE ON 
WEDNESDAY AND CONTINUE THROUGH FRIDAY. 
 
&&

.FIRE WEATHER...01/1220 PM.
GUSTY NORTHEAST WINDS WILL START TO FORM TODAY OVER INTERIOR LOS 
ANGELES COUNTY...WHICH COULD PRODUCE A FEW HOURS OF CRITICAL 
CONDITIONS OVER THE SANTA CLARITA VALLEY AS HUMIDITIES START TO 
DROP. THESE WINDS WILL STRENGTHEN AND PUSH DOWN INTO THE VALLEY AND 
COASTAL SECTIONS TONIGHT THROUGH THURSDAY. MEANWHILE...A RIDGE OF 
HIGH PRESSURE WILL BUILD OVER CALIFORNIA AND BRING HOT AND VERY DRY 
CONDITIONS TO THE REGION...WITH HUMIDITIES AROUND 10 PERCENT OVER 
MOST AREAS BY THURSDAY AFTERNOON. AS A RESULT...WIDESPREAD CRITICAL 
CONDITIONS ARE LIKELY OVER MUCH OF LOS ANGELES AND VENTURA COUNTIES 
ON THURSDAY. MOUNTAIN AND VALLEY AREAS HAVE THE BEST CHANCE TO 
EXCEED THE 6 HOUR DURATION THRESHOLDS...BUT SOME COASTAL AREAS 
SHOULD SEE A FEW HOURS OF CRITICAL CONDITIONS AS WELL. SAN LUIS 
OBISPO AND SANTA BARBARA COUNTIES WILL HAVE ELEVATED FIRE CONCERNS 
AS WELL WITH HOT AND VERY DRY CONDITIONS...BUT WINDS WILL BE WEAKER 
AND VERY LOCALIZED...MOSTLY CONFINED TO SELECT INTERIOR VALLEY AND 
MOUNTAIN LOCATIONS.

CONDITIONS WILL BECOME HOTTER AND DRIER THURSDAY NIGHT THROUGH 
SATURDAY...BUT THE WINDS WILL WEAKEN EACH DAY. THERE IS A CHANCE 
THAT RED FLAG CONDITIONS WILL CONTINUE THURSDAY NIGHT THROUGH 
FRIDAY...BUT LESS CERTAIN THAN THURSDAY DUE TO THE WEAKER WINDS. 
REGARDLESS...TRIPLE DIGIT TEMPERATURES AND WIDESPREAD SINGLE DIGIT 
HUMIDITIES WILL MAINTAIN A PERIOD OF ELEVATED FIRE CONCERN. COOLING 
AND MOISTENING EXPECTED GRADUALLY NEXT WEEK.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING (SEE LAXRFWLOX).
FIRE WEATHER WATCH (SEE LAXRFWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).

&&

$$

PUBLIC...MW
AVIATION/MARINE...SWEET
FIRE...KITTELL

WWW.WEATHER.GOV/LOSANGELES



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