833
FXUS66 KLOX 120754
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1254 AM PDT TUE MAY 12 2026
SYNOPSIS
11/103 PM.
SEVERAL DEGREES OF COOLING ARE EXPECTED TUESDAY AND WEDNESDAY AS
AN UPPER LOW MOVES THROUGH NORTHERN CALIFORNIA. LOW CLOUDS AND
FOG WILL MOVE INTO THE COASTAL VALLEYS THEN CLEARING TO NEAR THE
COAST BY AFTERNOON. GUSTY WINDS ARE POSSIBLE AT TIMES ACROSS THE
MOUNTAINS AND DESERTS. SLIGHT WARMING IS EXPECTED THURSDAY AND
FRIDAY.
SHORT TERM (TDY-THU)
11/842 PM.
HIGH PRESSURE ALOFT AND A SLIGHT REDUCTION OF THE MARINE LAYER
BROUGHT SOME WARMING TODAY ACROSS INTERIOR AREAS AS EXPECTED,
WITH MANY AREAS CLIMBING WELL INTO THE 90S. THE ONSHORE FLOW
KEPT A MARINE INFLUENCE AND COOLER TEMPERATURES NEAR THE COAST.
FOR TONIGHT, A SHALLOW AND STRONG MARINE INVERSION REMAINS IN
PLACE AND STARTING TO SEE SOME VISIBILITIES DROPPING ACROSS
PORTIONS OF THE COAST. IN EVENING UPDATE, HAVE ADDED PATCHY
DENSE FOG FOR TONIGHT AND SOME AREAS MAY REQUIRE A DENSE FOG
ADVISORY. BY TUESDAY MORNING, CROSS SECTIONS SHOW SOME DEEPENING
OF THE MARINE LAYER, WITH LOW CLOUDS AND FOG LIKELY EXTENDING
INTO SOME OF THE COASTAL VALLEYS. LOOKING FOR A SLOW TO NO
CLEARING DAY ON TUESDAY AFTERNOON FOR PORTIONS OF THE COAST.
HIGH PRESSURE WILL START TO WEAKEN AND SHIFT EAST TUESDAY, WITH
THE UPPER LEVEL FLOW TURNING MORE SOUTHEASTERLY. THE LOWERING
HEIGHTS AND MUCH STRONGER ONSHORE PRESSURE GRADIENTS WILL BRING
5 TO 10 DEGREES OF COOLING ACROSS MUCH OF THE FORECAST AREA
ON TUESDAY, EXCEPT ONLY A FEW DEGREES OF COOLING ACROSS THE
ANTELOPE VALLEY WHERE HIGHS WILL STILL CLIMB INTO THE 90S.
IN FACT, LATEST FORECAST PRESSURE GRADIENTS SHOWING THE POTENTIAL
FOR LAX-DAGGETT AND LAX-BAKERSFIELD GRADIENTS TO EXCEED +9 MB
WHICH IS RATHER SIGNIFICANT FOR THIS TIME OF YEAR. LOOKING AT
HISTORICAL PRESSURE GRADIENT PERCENTILE INFORMATION, A +9 LAX-
BAKERSFIELD GRADIENT WOULD BE NEAR ALL-TIME HIGHS FOR THE MONTH OF
MAY, AND LAX-DAGGETT WOULD EXCEED THE 97TH PERCENTILE. WITH THIS
IN MIND, LOOKING FOR A SIGNIFICANT INCREASE IN COVERAGE AND
STRENGTH OF ONSHORE WINDS ACROSS THE INTERIOR ON TUESDAY
AFTERNOON/EVENING, WITH GUSTS MOSTLY RANGING IN THE 30 TO 45 MPH
RANGE. IN EVENING UPDATE, HAVE INCLUDED A WIND ADVISORY FOR
TUESDAY AFTERNOON/EVENING FOR THE ANTELOPE VALLEY AND ADJACENT
WESTERN FOOTHILLS WHERE GUSTS UP TO 45 MPH ARE EXPECTED, AND COULD
LOCALLY REACH 50 MPH IN A FEW OF THE FAVORED FOOTHILL LOCATIONS.
THIS WILL LIKELY GENERATE SOME BLOWING DUST AND SAND WHICH COULD
LOCALLY RESTRICT VISIBILITIES. ANOTHER AREA OF CONCERN FOR
STRONGER ONSHORE WINDS WILL THE INTERIOR VALLEY OF SAN LUIS OBISPO
COUNTY WHERE GUSTS OF 35 TO 45 MPH WILL BE LIKELY, AND MAY
REQUIRE A WIND ADVISORY. THE STRENGTHENING ONSHORE WINDS COMBINED
WITH LINGERING WARM/DRY CONDITIONS WILL BRING ELEVATED TO LOCALLY
BRIEF CRITICAL FIRE WEATHER CONDITIONS ACROSS THE INTERIOR ON
TUESDAY AFTERNOON, THEREBY INCREASING THE RISK OF FAST-MOVING AND
LARGE GRASS FIRES.
ANOTHER ITEM TO KEEP AN EYE ON FOR TUESDAY WILL BE SOME INFLUX
OF MID LEVEL MOISTURE AND INSTABILITY AS THE UPPER FLOW TURNS
SOUTHEASTERLY. MODELS HAVE BEEN CONSISTENT WITH EMBEDDED
VORTICITY AREAS SWEEPING THROUGH THE INTERIOR ON TUESDAY AFTERNOON,
WITH SOME ELEVATED INSTABILITY (NAM LIFTED INDEX VALUES OF -4 TO
-6 AND MUCAPE VALUES OF 500 TO 700 J/KG). THE MAIN LIMITING FACTOR
WILL BE AVAILABLE MID LEVEL MOISTURE, WHICH LOOKS RATHER MINIMAL
AT THIS POINT. FOR NOW, WILL KEEP WITH A 5-10 PERCENT CHANCE OF A
BRIEF SHOWER OR THUNDERSTORM ACROSS THE INTERIOR, WITH THE BEST
CHANCES OVER THE SAN GABRIEL MOUNTAINS AND VENTURA COUNTY
MOUNTAINS. IF ANY CONVECTION WERE TO DEVELOP, FORECAST MODEL
SOUNDINGS SHOWING THAT ISOLATED DRY LIGHTNING AND GUSTY
DOWNDRAFTS WOULD BE THE MAIN CONCERNS, WITH DCAPE VALUES EXCEED
1000 J/KG.
AN UPPER LOW WILL MOVE THROUGH NORTHERN CALIFORNIA ON WEDNESDAY.
FOLLOWING THE UPPER LOW PASSAGE NORTHERLY FLOW ALOFT WILL
INCREASE ACROSS THE SANTA YNEZ RANGE AND WESTERN TRANSVERSE RANGE
CREATING INCREASING NORTHERLY WINDS IN THOSE AREAS, MAINLY FROM
LATE AFTERNOON THROUGH THE EARLY MORNING HOURS. FORECAST ENSEMBLE
GRADIENTS ARE STILL IN THE -3 TO -5 RANGE, WHICH WOULD LIKELY BE
STRONG ENOUGH FOR WIND ADVISORIES IN THE SANTA YNEZ RANGE. FURTHER
COOLING IS EXPECTED ON WEDNESDAY, WITH LITTLE CHANGE IN
TEMPERATURES ON THURSDAY.
LONG TERM (FRI-MON)
11/144 PM.
BUILDING HIGH PRESSURE AND CONTINUED OFFSHORE FLOW FROM THE NORTH
WILL GREATLY REDUCE OR ELIMINATE THE LOW CLOUDS ON FRIDAY. THERE
WILL BE A DECENT BUMP UP IN TEMPS OF 3 TO 6 LOCALLY 8 DEGREES
ACROSS THE AREA.
FURTHER WARMING SATURDAY WITH LIMITED OR NO MARINE LAYER CLOUDS
WILL BRING MAX TEMPS INTO THE 70S ACROSS THE CSTS AND 80S IN THE
VLYS OR 3 TO 6 DEGREES OVER NORMAL.
WEAK TROFFING WILL MOVE INTO THE AREA NEXT SUNDAY. IN ADDITION
THERE WILL BE AN INCREASE IN THE ONSHORE FLOW TO THE EAST. MAX
TEMPS WILL LIKELY FALL A DEGREE OR 2 OVER MOST AREAS.
IN ADDITION THE NORTHERLY GRADIENTS WILL LIKELY BRING ADVISORY
LEVEL WIND GUSTS TO THE WESTERN PORTION OF THE SBA SOUTH COAST
LATE IN THE AFTERNOONS AND EVENINGS.
AVIATION
12/0752Z.
HIGH CONFIDENCE IN KWJF AND KPMD TAFS.
LOW TO MODERATE CONFIDENCE IN REMAINDER OF TAFS. TIMING OF FLIGHT
CATEGORY CHANGES MAY BE OFF BY 3 HOURS AND ONE FLIGHT CATEGORY.
KLAX...MODERATE CONFIDENCE IN TAF, WITH CIGS LIKELY TO PERSIST
THROUGH TUE AFTERNOON. VSBY BETWEEN 1/2-2SM POSSIBLE THROUGH
16Z-18Z.
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 30 PERCENT CHC OF
VFR CONDITIONS REMAINING THROUGH PERIOD, BUT LATEST TRENDS
INDICATING INCREASING POTENTIAL FOR IFR/LIFR CIGS AROUND SUNRISE.
MARINE
12/1253 AM.
WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY (SCA)
LEVELS THROUGH WEDNESDAY MORNING.
WEDNESDAY AFTERNOON THROUGH THE WEEKEND, WINDS AND SEAS WILL
START TO STRENGTHEN/BUILD, WITH SCA WINDS ACROSS THE OUTER WATERS
STARTING LATE WEDNESDAY NIGHT AND SEAS REACHING STEEP AND CHOPPY
SCA LEVELS AROUND FRIDAY NIGHT. THERE IS A 20-40 PERCENT CHANCE OF
SCA WINDS ACROSS THE INNER WATERS, WITH THE HIGHEST CHANCES EACH
AFTERNOON AND EVENINGS. GALE FORCE WINDS WILL BE POSSIBLE ACROSS
THE OUTER WATERS AS EARLY AS THURSDAY AFTERNOON, WITH HIGHEST
(30-50 PERCENT) CHANCES ON SATURDAY INTO SUNDAY.
AS FOR SEAS, LARGE SCA LEVEL SEAS OF 10-12+ FEET WILL BE POSSIBLE
FOR THE OUTER AND NORTHERN WATERS BY THIS WEEKEND.
DENSE FOG WILL BE POSSIBLE THROUGH MID MORNING TODAY.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY IN EFFECT FROM 2 PM THIS AFTERNOON TO 10 PM PDT
THIS EVENING FOR ZONES 381-383. (SEE LAXNPWLOX).
PZ...NONE.
PUBLIC...GOMBERG/RORKE
AVIATION...SCHOENFELD
MARINE...MUNROE/LUND
SYNOPSIS...MW
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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