185
FXUS66 KLOX 160545
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
945 PM PST WED JAN 15 2025
SYNOPSIS
15/748 PM.
LOCALLY GUSTY NORTHEAST WINDS WILL CONTINUE INTO THURSDAY MORNING
BEFORE ONSHORE FLOW ARRIVES IN THE AFTERNOON. THIS WILL RESULT IN
A SIGNIFICANT COOLING TREND THROUGH THE WEEKEND WITH HIGHER
HUMIDITIES. ANOTHER SANTA ANA WIND EVENT IS POSSIBLE LATER MONDAY
INTO TUESDAY. MUCH BELOW NORMAL DAYTIME AND NIGHTTIME TEMPERATURES
WILL CONTINUE THROUGH MOST OF NEXT WEEK.
SHORT TERM (WED-SAT)
15/816 PM.
***UPDATE***
WINDS HAVE SUBSIDED BELOW ADVISORY LEVELS THIS EVENING, WITH PEAK
OFFSHORE GUSTS IN THE 30 TO 40 MPH RANGE IN THE SANTA ANA WIND-
PRONE AREAS OF LA AND VENTURA COUNTIES. FOR MOST OF THE AREA
EXPECT WINDS TO CONTINUE TO SUBSIDE OVERNIGHT INTO THURSDAY,
BEFORE TURNING ONSHORE THURSDAY AFTERNOON. HOWEVER IN SOME OF THE
MOUNTAIN AREAS, MAINLY THE WESTERN SAN GABRIELS AND I-5 CORRIDOR
AND THE SANTA SUSANAS, ISOLATED GUSTS SHOULD REMAIN BETWEEN 35 TO
40 MPH INTO THURSDAY MORNING, MAINTAINING RED FLAG CONDITIONS
THROUGH THE MID-AFTERNOON HOURS.
ANOTHER ROUND OF COLD OVERNIGHT LOWS IS EXPECTED IN THE WIND
SHELTERED AREAS, WITH COOLER TEMPERATURES FOR THURSDAY'S HIGHS.
MOST AREAS WILL BE IN THE 60S, WITH A FEW OF THE WARMER LOCATIONS
HITTING THE LOW 70S. THIS IS DUE TO THE SHIFT TO ONSHORE FLOW
FORECAST FOR THE AFTERNOON HOURS, GENERALLY UP TO 15 MPH FOR THE
COAST AND VALLEYS, AND UP TO 25 MPH OVER THE SANTA MONICA
MOUNTAINS.
***FROM PREVIOUS DISCUSSION***
DAY 9 OF THIS LENGTHY OFFSHORE WIND EVENT IS GOING ALONG AS
EXPECTED WITH SOME LINGERING ADVISORY LEVEL NORTHEAST WINDS ACROSS
LA/VENTURA COUNTIES. THOSE WINDS ARE STARTING TO WEAKEN NOW AS
THE GRADIENT TABLE SHOWS ONSHORE TRENDS DEVELOPING. THERE WILL
STILL BE ENOUGH OFFSHORE FLOW TONIGHT INTO EARLY THURSDAY MORNING
TO GENERATE SOME LOCALLY GUSTY WINDS, MAINLY IN THE MOUNTAINS. BY
THURSDAY AFTERNOON A SOLID ONSHORE FLOW WILL BE ARRIVING ALONG THE
COAST AND WORKING ITS WAY INLAND THROUGH THE REST OF THE DAY,
FINALLY BRINGING THIS LONG OFFSHORE STRETCH TO AN END.
FOR FRIDAY AND THE WEEKEND, MUCH COOLER TEMPERATURES ARE EXPECTED
AS THE COOL ONSHORE FLOW OFF THE OCEAN WILL PREVAIL. IN ADDITION
MODELS ARE INDICATING A RATHER DEEP MARINE LAYER, AROUND 3000 FEET
OR POSSIBLY HIGHER, DEVELOPING FRIDAY WHICH SHOULD RESULT IN A
FAIR AMOUNT OF STRATUS CLOUDS ACROSS COAST AND VALLEYS THROUGH AT
LEAST THE MORNING. GIVEN THE LOW SUN ANGLE THIS TIME OF YEAR IT'S
POSSIBLE THIS STRATUS LAYER COULD LINGER WELL INTO THE AFTERNOON.
FORECAST SOUNDINGS INDICATE A LOWERING INVERSION SATURDAY AS WELL
AS RATHER STRONG OFFSHORE TREND SO IF THIS PERSISTS LOW CLOUDS ON
SATURDAY SHOULD CLEAR SOONER (OR MAY NOT FORM AT ALL). HOWEVER,
TEMPERATURES ARE STILL EXPECTED TO BE BELOW NORMAL.
LONG TERM (SUN-WED)
15/213 PM.
ASIDE FROM THE MARINE LAYER UNCERTAINTY THIS WEEKEND, THE OVERALL
WEATHER PATTERN WILL BE QUITE BENIGN. MODELS ARE SHOWING A LIGHT
OFFSHORE TREND AGAIN SUNDAY, THOUGH NOT ENOUGH FOR ANY SIGNIFICANT
WINDS. TEMPERATURES (DAY AND NIGHT) WILL REMAIN SEVERAL DEGREES
BELOW NORMAL, THOUGH A STRATUS LAYER WOULD RESULT IN WARMER
NIGHTS.
FOR EARLY NEXT WEEK, AN INCREASING NUMBER OF ENSEMBLE SOLUTIONS
ARE INDICATING A RETURN OF OFFSHORE FLOW AND SANTA ANA WINDS,
ESPECIALLY LATER MONDAY INTO TUESDAY. THOSE SOLUTIONS HAVE BEEN
BOUNCING AROUND A BIT SO CONFIDENCE IN STRENGTH AND TIMING IS
STILL ON THE LOWER SIDE. HOWEVER, TODAY'S 12Z ECMWF ENSEMBLES
DEFINITELY TRENDED STRONGER WITH THE WINDS. TEMPERATURES EXPECTED
TO REMAIN BELOW NORMAL THROUGH THE PERIOD, THOUGH SOME
MODIFICATION OF THAT IS POSSIBLE FOR AREAS CLOSER TO THE COAST IF
OFFSHORE WINDS DEVELOP. THIS EVENT COULD BE EVEN DRIER THAN THE
LAST COUPLE OF SANTA ANAS AS PW'S ARE EXPECTED TO BE NEAR OR EVEN
BELOW A TENTH OF AN INCH.
AVIATION
16/0544Z.
AT 0423Z AT KLAX, THERE WAS NO MARINE LAYER NOR INVERSION.
HIGH CONFIDENCE IN VFR CONDS AT ALL SITES THROUGH 06Z. LIGHT
TURBULENCE IS POSSIBLE THRU 12Z (ESP NEAR FOOTHILLS AND MTNS).
KLAX...HIGH CONFIDENCE IN VFR CONDS THROUGH 06Z. THEN LOWER
CONFIDENCE AS THERE WILL BE AN INCREASING CHC OF LOW CLOUDS. IF
LOW CLOUDS DO ARRIVE THERE IS A 30 PERCENT CHC THAT CIGS WILL BE
HIGHER THAN FCST LIKELY BKN012. GOOD CONFIDENCE THAT ANY EAST WIND
COMPONENT WILL BE UNDER 7 KT.
KBUR...HIGH CONFIDENCE IN CAVU TAF.
MARINE
15/803 PM.
FOR THE OUTER WATERS, THERE IS A 30% CHANCE OF SMALL CRAFT
ADVISORY (SCA) LEVEL WINDS FROM POINT CONCEPTION TO SAN NICOLAS
ISLAND FRIDAY AFTERNOON/EVE INTO EARLY SAT MORNING (PZZ673/676).
OTHERWISE, SUB ADVISORY CONDITIONS ARE EXPECTED.
FOR THE INNER WATERS NORTH OF PT SAL, SUB ADVISORY CONDS ARE
EXPECTED THRU SUN NIGHT.
IN THE SANTA BARBARA CHANNEL, EAST TO NORTHEAST WINDS ARE
FORECAST TO INCREASE LATE TONIGHT AND REACH SCA LEVELS FROM
VENTURA TO POINT MUGU AND OUT TO SANTA CRUZ ISLAND THROUGH THURS
MORNING. HOWEVER, THERE IS A 40% CHANCE THAT WINDS WILL NOT REACH
ADVISORY CRITERIA AND THE SCA MAY BE DROPPED OFF EARLY. CONDITIONS
ARE THEN EXPECTED TO REMAIN FAIRLY BENIGN THRU SUN NIGHT, EXCEPT
FOR A 20% CHANCE OF SCA WIND GUSTS IN THE FAR WESTERN PORTION OF
THE CHANNEL FRI EVENING TO SAT MORNING.
FOR THE SOUTHERN INNER WATERS, ANY SCA LEVEL WIND GUSTS WILL
LIKELY STAY CONFINED TO THE EXTREME NORTHERN PORTIONS OF THE ZONE
EXTENDING OUT TO SANTA CRUZ ISLAND OVERNIGHT THRU THU MORNING.
THEN SCA CONDS ARE NOT EXPECTED THRU THE WEEKEND.
FIRE WEATHER
15/403 PM.
...RED FLAG WARNINGS IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA
COUNTIES, AND PARTS OF SAN LUIS OBISPO AND SANTA BARBARA COUNTIES
THROUGH 6 PM TODAY...
...RED FLAG WARNING UNTIL 3 PM THURSDAY FOR WESTERN SAN GABRIEL
MOUNTAINS, I-5 CORRIDOR, AND SANTA SUSANA MOUNTAINS...
DISCUSSION
A RED FLAG WARNING REMAINS IN EFFECT FOR PORTIONS OF SOUTHWEST
CALIFORNIA THROUGH THIS AFTERNOON, WITH PORTIONS OF LA AND VENTURA
COUNTY MOUNTAINS LINGERING INTO THURSDAY AFTERNOON. NE-E WINDS WILL
CONTINUE TO DIMINISH TODAY, WITH GUSTS UP TO 40 MPH LINGERING INTO
THURSDAY AFTERNOON FOR THE I-5 CORRIDOR, WESTERN SAN GABRIEL MOUNTAINS,
AND SANTA SUSANA MOUNTAINS. MINIMUM HUMIDITIES WILL RANGE FROM 8 TO 20
PERCENT WITH POOR OVERNIGHT RECOVERIES.
ELEVATED TO BRIEF CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE
THROUGH THURSDAY AS HUMIDITIES REMAIN LOW INTO THURSDAY NIGHT, THEN
IMPROVING HUMIDITIES ARE EXPECTED FRIDAY AND SATURDAY WINDS REVERSE TO
ONSHORE. STARTING SUNDAY, WINDS WILL SWITCH BACK TO OFFSHORE WITH VERY
DRY CONDITIONS. MONDAY AND TUESDAY LOOK TO BE EXTREMELY DRY WITH A 50 TO
60 PERCENT CHANCE OF MODERATE SANTA ANA WINDS, RESULTING IN A 70
PERCENT CHANCE OF RED FLAG WARNINGS OVER THE TYPICAL LOS ANGELES AND
VENTURA SANTA ANA WIND CORRIDORS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...RED FLAG WARNING IN EFFECT UNTIL 3 PM PST THURSDAY FOR ZONES
375-378-379. (SEE LAXRFWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 AM PST THURSDAY FOR
ZONE 650. (SEE LAXMWWLOX).
PUBLIC...MW/SMITH
AVIATION...RORKE
MARINE...BLACK/LEWIS
FIRE...LUND
SYNOPSIS...MW/SMITH
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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