040
FXUS66 KLOX 231056
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
256 AM PST TUE DEC 23 2025
SYNOPSIS
22/159 AM.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH SUNDAY IN MOST
AREAS EXCEPT THE COAST. A COOLING TREND WILL BEGIN MONDAY AS A
STRONG STORM APPROACHES WITH INCREASING CLOUDS. RAIN WILL BEGIN
TUESDAY IN MOST AREAS WITH PERIODS OF HEAVY RAIN TUESDAY NIGHT AND
WEDNESDAY AS WELL AS VERY STRONG WINDS. SHOWERS ARE EXPECTED TO
CONTINUE ON CHRISTMAS DAY AND THROUGH NEXT WEEKEND.
SHORT TERM (TDY-THU)
23/251 AM.
***STRONG ATMOSPHERIC WINTER STORM WITH DANGEROUS FLOODING AND
ROCK/MUD SLIDES TONIGHT THROUGH THURSDAY EVENING***
THE 00Z AND 06Z MDLS AND ENSEMBLES ARE IN DECENT AGREEMENT AND DO
NOT DEVIATE FROM THE CURRENT FORECAST. ALL HI REZ MDLS DO SHOW
SOME TIMING AND COVERAGE DIFFERENCES, BUT NOTHING SIGNIFICANT
ENOUGH TO INITIATE ANY CHANGES TO THE FORECAST.
THIS MORNING WILL BE CLOUDY WITH A CHC OF A SPRINKLE JUST ABOUT
ANYWHERE. THE CHC OF RAIN WILL INCREASE THIS AFTERNOON AS THE AR
SETS UP INTO A MORE N TO S ORIENTATION AND APPROACHES THE STATE.
EVERYTHING STILL POINTS FOR A MAJOR STORM TO AFFECT SRN CA LATE
THIS EVENING AND THROUGH WEDNESDAY. A STRONG UPPER LEVEL
SOUTHWESTERLY JET WILL INTERACT WITH A VERY MOIST TROPICAL AIR
MASS WITH PWAT VALUES PEAKING AROUND 1.5 INCHES AND IVT VALUES
BETWEEN 750 AND 1000 KG/M-S. THE COMBINATION OF STRONG JET
DYNAMICS, LOTS OF WARM AIR ADVECTION, AND STRONG SOUTHERLY WINDS
WILL BRING PROLONGED PERIODS OF HEAVY RAINFALL (ESPECIALLY ACROSS
SOUTH FACING SLOPES SOUTH OF POINT CONCEPTION). BECAUSE OF THIS
THE SOUTH FACING MTNS AND FOOTHILLS AS WELL AS THE COASTAL AND
VLY AREAS BELOW THEM WERE DESIGNATED AS A HIGH RISK AREA FOR
DANGEROUS AND WIDESPREAD FLOODING CONCERNS. SOME OF THE LATEST
HIGH RESOLUTION MODEL DATA SHOW RAIN RATES LOCALLY REACHING 1.50
INCHES PER HOUR (ESPECIALLY ACROSS FAVORED SOUTH FACING SLOPES).
RAIN...LIGHT RAIN WILL BEGIN ACROSS ALL AREAS DURING THIS
AFTERNOON. THE FIRST, AND MORE SIGNIFICANT, IMPULSE OF THE AR
WILL MOVE ACROSS THE AREA LATER THIS EVENING AND WEDNESDAY. AFTER
A RELATIVELY "LULL" WEDNESDAY NIGHT, A SECOND IMPULSE WILL MOVE
ACROSS THE AREA ON CHRISTMAS DAY.
RAIN TOTALS THROUGH CHRISTMAS DAY:
NORTH OF POINT CONCEPTION: 2-4 INCHES COASTAL/VALLEY AREAS AND
4-7INCHES FOR FOOTHILLS/MOUNTAINS.
SOUTH OF POINT CONCEPTION: 3-6 INCHES COASTAL/VALLEY AREAS AND
5-11 INCHES FOOTHILLS/MOUNTAINS.
RAIN RATES: PEAK RAINFALL RATES NORTH OF POINT CONCEPTION ARE
EXPECTED TO BE IN THE 0.40-1.00 INCH/HOUR RANGE WHILE SOUTH OF
POINT CONCEPTION 0.60-1.25 INCH/HOUR RATES ARE EXPECTED. THERE IS
A 20-30 PERCENT CHANCE OF ISOLATED RATES AS HIGH AS 1.50 INCHES
PER HOUR ACROSS FAVORED SOUTH FACING SLOPES (SOUTH OF POINT
CONCEPTION).
THUNDERSTORMS: UNSTABLE AIR, ASSOCIATED WITH THE STORM, ALONG WITH
STRONG JET DYNAMICS WILL BRING A CHANCE OF OF EMBEDDED
THUNDERSTORMS TONIGHT AND WEDNESDAY TO ALL AREAS. THE STORM
PREDICTION CENTER PLACED THE AREA UNDER A MARGINAL RISK OF SEVERE
THUNDERSTORMS. ANY TSTM THAT FORMS WILL BRING BRIEF INTENSE
RAINFALL. MORE IMPORTANTLY, DUE TO THE STRONG UPPER LEVEL WINDS,
ANY CONVECTIVE ELEMENT WILL HAVE A HIGH RISK TO BRING DAMAGING
WINDS. ADDITIONALLY, THERE WILL BE A CHANCE OF WEAK, SHORT-LIVED,
TORNADOES OR WATERSPOUTS, ESPECIALLY DURING THE SECOND WAVE OF
ENERGY ON THURSDAY WHEN THERE IS COLDER AIR ALOFT AND MORE
INSTABILITY.
SNOW: SNOW LEVELS WILL REMAIN ABOVE THE 7500-8000 FOOT RANGE
THROUGH CHRISTMAS EVE, BUT WILL DROP TO AROUND 7000 FEET ON
CHRISTMAS DAY. SO, NO WINTER WEATHER ISSUES ARE EXPECTED THROUGH
CHRISTMAS EVE, BUT SOME DECENT ACCUMULATING SNOWFALL WILL BE
LIKELY AT THE RESORT LEVEL ON CHRISTMAS DAY.
WIND: STRONG AND GUSTY SOUTHEAST TO SOUTH WINDS ARE EXPECTED
TUESDAY THROUGH CHRISTMAS DAY. WIDESPREAD GUSTS OF 35-55 MPH ARE
HIGHLY LIKELY ACROSS ALL AREAS. WARNING LEVEL GUSTS OF 60 TO 80
MPH ARE LIKELY ACROSS SBA/SLO COUNTIES AS WELL AS THE MTNS AND
DESERTS OF VTA/LA COUNTIES FROM NOON TODAY THROUGH 3PM CHRISTMAS
DAY.
IMPACTS: WIDESPREAD AND SIGNIFICANT URBAN FLOODING WILL BE LIKELY
ALONG WITH ROCK/MUDSLIDES AND DEBRIS FLOWS (WITH THE THREAT NOT
JUST CONFINED TO BURN AREAS). THE HIGH INTENSITY RAINFALL AND
PROLONGED DURATION OF HEAVY RAIN WILL BRING THE THREAT OF DEBRIS
FLOWS TO THE RECENT BURN SCARS. STREAMS, RIVERS, AND CREEKS WILL
ALSO SEE RAPID FLOWS, THEREBY INCREASING THE THREAT OF SWIFT WATER
RESCUES. A FLOOD WATCH IS IN EFFECT FOR ALL AREAS OF SOUTHWEST
CALIFORNIA DUE TO THESE MAJOR HYDROLOGICAL RISKS. THE COMBINATION
OF INCREASINGLY SATURATED SOIL AND THE STRONG WINDS WILL BRING THE
POTENTIAL FOR WIDESPREAD DOWNED TREES AND POWER LINES, ESPECIALLY
IN AREAS UNDER A HIGH WIND WARNING.
ONCE AGAIN, THIS IS A VERY DANGEROUS HOLIDAY STORM. ANYONE
TRAVELING ON CHRISTMAS EVE OR CHRISTMAS DAY WILL NEED TO EXERCISE
EXTREME CAUTION. MAKE SURE TO TAKE THE PROPER PROTECTIVE ACTIONS
BEFORE THE STORM HITS.
LONG TERM (FRI-MON)
23/1226 AM.
A SECOND COLDER TROF/UPPER LOW DROPS INTO THE AREA ON FRIDAY
MOVES THROUGH THE AREA ON SATURDAY. RAIN WILL BE LIKELY ACROSS THE
AREAS ON FRIDAY AS THE MAX LIFT OF THE TROF MOVES INTO THE AREA.
SNOW WILL BE MUCH MORE OF A CONCERN WITH SNOW LEVELS BETWEEN 4500
AND 5000 FT. RAIN WILL TURN TO SHOWERS AND DIMINISH ON SATURDAY AS
THE STORM MOVES OUT OF THE AREA. THE BEST ESTIMATE FOR RAINFALL
FRIDAY (MIDNIGHT TO MIDNIGHT) IS ABOUT A HALF INCH FOR COASTS AND
A HALF INCH TO AN INCH IN THE MTNS AND FOOTHILLS. SATURDAY'S RAIN
WILL BE A QUARTER INCH OR LESS.
VERY LITTLE MDL AGREEMENT FOR THE SUNDAY / MONDAY TIME FRAME AS
THE GFS IS FORECASTING AN UPPER LOW WITH 560 HGTS AND THE EC A
RIDGE WITH 579 HGTS OVER THE AREA. A MAJORITY OF THE ENSEMBLES
FAVOR THE EC SOLUTION AND THE OFFICIAL FORECAST IS DRY WITH A
WARMING TREND - THOUGH NOT AS ROBUST AS THE OPERATIONAL EC WOULD
HAVE.
AVIATION
23/0544Z.
AT 0505Z AT KLAX, THE MARINE LAYER WAS 1100 FT DEEP. THE TOP OF
THE INVERSION WAS NEAR 2900 FEET WITH A TEMPERATURE OF 17 C.
HIGH CONFIDENCE IN VFR TAFS FOR DESERT AIRFIELDS (KPMD & KWJF).
MODERATE CONFIDENCE IN THE REMAINDER OF THE TAF. CIGS SHOULD RISE
THROUGH AT LEAST 21Z. EXPECT MOSTLY VFR CIGS BY 17Z. LOWER CIGS
ARE LIKELY AFTER 00Z WITH A CHANCE OF LIGHT RAIN. BY 05Z RAIN
WILL BEGIN TO OVERSPREAD THE AREA.
MODERATE TO HEAVY RAIN WITH VERY STRONG WINDS WILL OVERSPREAD ALL
TAF SITES AFTER 24/07Z AND WILL CONTINUE THROUGH THE BULK OF THE
DAY.
KLAX...MODERATE CONFIDENCE IN TAF. GOOD CONFIDENCE THAT CIGS WILL
SLOWLY RISE THROUGH 20Z BUT FLIGHT CAT TRANSITIONS COULD BE OFF
BY 2 HOURS. LOWERING CIGS ARE LIKELY AFTER 00Z. RAIN WILL LIKELY
DEVELOP BY 06Z. GOOD CONFIDENCE THAT EAST WINDS WILL DEVELOP AFTER
08Z BUT WILL REMAIN UNDER 8KT THROUGH 14Z. AFTER 14Z AN 8 TO 10
KT EAST WIND IS LIKELY. THE EAST WINDS WILL BECOME GREATER THAN
10KT BETWEEN 02Z AND 04Z AND WILL LIKELY CONTINUE TO INCREASE
THEREAFTER. STRONG EAST WINDS ARE THEN LIKELY THROUGH WEDNESDAY.
KBUR...MODERATE CONFIDENCE IN TAF. GOOD CONFIDENCE THAT CIGS WILL
SLOWLY RISE THROUGH 20Z BUT FLIGHT CAT TRANSITIONS COULD BE OFF
BY 2 HOURS. LOWERING CIGS ARE LIKELY AFTER 00Z. RAIN WILL LIKELY
DEVELOP AT THE END OF THE TAF PERIOD.
MARINE
23/233 AM.
A STRONG WINTER STORM WILL BRING WIDESPREAD, DANGEROUS MARINE
WEATHER TO THE COASTAL WATERS WITH EXCEPTIONALLY STRONG WINDS,
ROUGH SHORT- PERIOD SEAS, HEAVY RAIN, AND A CHANCE FOR
THUNDERSTORMS LATE TODAY THROUGH THURSDAY. VESSELS, ESPECIALLY
SMALL VESSELS ARE STRONGLY ADVISED TO REMAIN IN SAFE HARBOR FOR
THE DURATION OF THE STORM, AS THESE CONDITIONS CAN SINK BOATS.
SOUTH-FACING HARBORS WILL ALSO BE ESPECIALLY VULNERABLE TO THE
SOUTH SWELL AND STRONG WINDS.
DETAILS:
SOUTH TO SOUTHEAST WINDS AND SEAS WILL RAPIDLY INCREASE TO
DANGEROUS LEVELS THIS AFTERNOON TO EVENING AS A STORM SYSTEM
APPROACHES THE COASTAL WATERS. SCA LEVEL SOUTHERLY AND SEAS WILL
FURTHER STRENGTHEN TO GALE TO STORM FORCE CONDITIONS THIS
AFTERNOON TO EVENING, LIKELY STRONGEST NORTH OF POINT CONCEPTION.
THESE STRONG WINDS ARE EXPECTED TO IMPACT THE NEARSHORE WATERS,
ESPECIALLY FOR UNSHELTERED SOUTH- FACING COASTLINES AND AREAS
NORTH OF POINT CONCEPTION.
LARGE SOUTHERLY SHORT- PERIOD SEAS WILL DEVELOP TONIGHT AND
SHOULD LINGER WEDNESDAY INTO THURSDAY, LEADING TO ELEVATED, CHOPPY
SEAS AT SOUTH-FACING HARBOR ENTRANCES. THERE IS ALSO A 15-30%
CHANCE OF THUNDERSTORMS LATE TODAY THROUGH EARLY THURSDAY, WHICH
WILL BRING A THREAT OF ERRATIC GUSTY WINDS, HEAVY DOWNPOURS,
WATERSPOUTS, AND CLOUD-TO-OCEAN LIGHTNING.
BEACHES
23/248 AM.
A SHORT TO MODERATE PERIOD SOUTHERLY WIND SWELL WILL PRODUCE
CHOPPY, LARGE, DANGEROUS SURF AND RIP CURRENTS THROUGH THURSDAY.
A LONGER PERIOD NW SWELL WILL TAKE OVER FRIDAY, AND SURF WILL
CONTINUE TO BE SIGNIFICANT INTO THE WEEKEND. IT IS BEST TO REMAIN
OUT OF THE WATER DURING THIS TIME. SEE HIGH SURF ADVISORY FOR
DETAILS.
WHILE PEAK TIDES ARE NOT VERY HIGH, MINOR TO LOCALLY MODERATE
COASTAL FLOODING MAY OCCUR FOR SOUTH FACING SHORES THROUGH
THURSDAY.
LOX WATCHES/WARNINGS/ADVISORIES
CA...HIGH WIND WARNING IN EFFECT FROM NOON TODAY TO 3 PM PST
THURSDAY FOR ZONES 38-87-88-340>353-369-370-376>383-549-550. (SEE LAXNPWLOX).
FLOOD WATCH REMAINS IN EFFECT FROM THIS AFTERNOON THROUGH
THURSDAY EVENING FOR ZONES 38-87-88-340>358-362-366>383-548. (SEE LAXFFALOX).
HIGH SURF ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO 11 AM
PST SATURDAY FOR ZONES 340-346-349-350. (SEE LAXCFWLOX).
WIND ADVISORY IN EFFECT FROM NOON TODAY TO 3 PM PST THURSDAY
FOR ZONES 354>358-362-366>368-371>375-548. (SEE LAXNPWLOX).
HIGH SURF ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 11 AM
PST SATURDAY FOR ZONES 354-362-366. (SEE LAXCFWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 1 PM PST THIS AFTERNOON
FOR ZONES 645-670-673. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 1 PM
PST THIS AFTERNOON FOR ZONES 650-655-676. (SEE LAXMWWLOX).
GALE WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 1 PM PST
WEDNESDAY FOR ZONES 650-655-676. (SEE LAXMWWLOX).
PUBLIC...THOMPSON/GOMBERG/RORKE
AVIATION...RORKE
MARINE...RM/PHILLIPS/BLACK
BEACHES...RM
SYNOPSIS...MW
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page