496
FXUS66 KLOX 200411
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
911 PM PDT SUN OCT 19 2025
SYNOPSIS
19/845 PM.
SHORTWAVE RIDGING ALOFT WILL KEEP A WARMER WEATHER PATTERN IN
PLACE ACROSS MUCH OF THE REGION INTO MONDAY, BUT ONSHORE FLOW
WILL GRADUALLY DEVELOP THROUGH TUESDAY AND BRING SOME COOLING
THROUGH MIDWEEK. AN UPPER-LEVEL TROUGH OF LOW PRESSURE WILL MOVE
OVER THE REGION BETWEEN TUESDAY AND WEDNESDAY AND COULD BRING A
FEW SHOWERS TO THE REGION.
SHORT TERM (TDY-TUE)
19/910 PM.
THE LATEST SATELLITE IMAGERY INDICATES A CUTOFF TROUGH OF LOW
PRESSURE ABOUT 550 MILES SOUTH-SOUTHWEST OF POINT CONCEPTION THIS
EVENING. MEANWHILE, SHORTWAVE RIDGING DEVELOPING AHEAD OF THE
TROUGH IS IN PLACE OVER THE REGION. OFFSHORE FLOW IN PLACE EARLIER
TODAY HAS TRANSITIONED TO WEAK ONSHORE FLOW THIS EVENING, BUT
RIDGING ALOFT SHOULD WEAKEN ONSHORE PRESSURE GRADIENTS OVERNIGHT
ACROSS THE SOUTHLAND. LOW CLOUDS AND FOG ARE RETURNING AGAIN TO
THE CENTRAL COAST THIS EVENING, BUT THE MARINE LAYER LOW CLOUD
FIELD LOOKS TO BE STRUGGLING. THE FORECAST KEEP LOW CLOUDS AND
PATCHY DENSE FOG ACROSS THE COASTAL AREAS TONIGHT AND INTO MONDAY
MORNING, BUT CONFIDENCE REMAINS LOW IN DEVELOPMENT ACROSS THE
SOUTHLAND. LOW CLOUDS WERE EXPANDED A LITTLE INTO THE SANTA YNEZ
VALLEY OVERNIGHT AND INTO MONDAY MORNING DUE TO STRONGER ONSHORE
FLOW ACROSS THE NORTHERN PORTION OF THE AREA. SOME COOLING COULD
DEVELOP ALONG THE CENTRAL COAST ON MONDAY AND THE FORECAST TIPS
THAT WAY, BRING TEMPERATURES DOWN SLIGHTLY.
***FROM PREVIOUS DISCUSSION***
A QUASI-STATIONARY CLOSED UPPER LEVEL LOW POSITIONED 600 MILES TO
OUR SOUTHWEST WILL BEGIN TO MOVE TOWARDS OUR REGION ON TUESDAY.
GUIDANCE HAS BEEN CONSISTENT WITH THIS FEATURE INDICATING A GOOD
CHANCE FOR MARINE LAYER DRIZZLE, ESPECIALLY NORTH OF PT
CONCEPTION. LIGHT RAIN IS EVEN POSSIBLE NEAR THE FOOTHILLS WHERE
OROGRAPHIC LIFT IS MAXIMIZED ON THE WINDWARD SIDE. SOME OF
ENSEMBLE SOLUTIONS INDICATE AN AFTERNOON ARRIVAL OF THE LOW WHICH
COULD TRIGGER SOME CONVECTION ACROSS THE INTERIOR MOUNTAINS (<10%
CHANCE). ANOTHER LIMITING FACTOR COULD BE THE LACK OF MOISTURE
INDICATED BY MODEL SOUNDINGS.
AS HEIGHTS & MARINE LAYER DEPTH INCREASE, EXPECT MAX TEMPERATURES
TO COOL SIGNIFICANTLY ESPECIALLY ACROSS INTERIOR LOCATIONS WHERE
DEPARTURES ARE EXPECTED TO BE 8 TO 15 F BELOW AVG ON WEDNESDAY.
60S TO 70S FOR ALL LOCATIONS EXCEPT IN THE 50S FOR MOUNTAINOUS
LOCATIONS ABOVE ROUGHLY 5,000FT.
LONG TERM (WED-SAT)
19/208 PM.
WEAK RIDGING IS EXPECTED TO BUILD IN AFTER THE LOW EXITS TO THE
EAST THURSDAY INTO FRIDAY. RISING HEIGHTS COMBINED WITH REDUCED
PRESSURE GRADIENTS WILL LEAD TO A REDUCTION IN LOW CLOUDS, ESP
SOUTH OF POINT CONCEPTION. CLOUD COVERAGE OUTSIDE OF MORNING LOW
CLOUDS SHOULD BE MINIMAL DURING THIS TIMEFRAME. STILL ON PACE FOR
3 TO 6 F OF WARMING ON THURSDAY, WITH AN ADDITIONAL 2 TO 4 F ON
FRIDAY BRINGING MAX TEMPERATURES NEAR NORMAL.
A SERIES OF DISTURBANCES WILL MOVE ALONG AN ANOMALOUS JET STREAK
IMPINGING UPON NORTHERN CALIFORNIA. THE GEFS/EPS & ECWMF-AIFS
CONTINUES THE TREND OF REDUCING THE AMPLITUDE OF THE UPPER WAVE
PATTERN. WITH LONGER WAVELENGTHS, THE STORM TRACK WOULD STAY NORTH
WITH LESS IMPACT IF THE MAJORITY OF ENSEMBLES MEMBERS ARE REALIZED.
THIS WOULD TRANSLATE TO LOWER CHANCES OF RAINFALL IF THIS TREND
CONTINUES FOR THE SATURDAY NIGHT AND SUNDAY TIMEFRAME.
THERE HAS BEEN A FAIR AMOUNT OF CONSISTENCY OF A RIDGE BUILDING
ONCE THE AFOREMENTIONED TROUGH PASSES OUR REGION'S MERIDIAN.
AT THIS TIME, BOTH ENSEMBLES AND DETERMINISTIC SOLUTIONS SHOW
GOOD SIGNALING FOR BOTH N-NE OFFSHORE GRADIENTS. THIS COULD
TRANSLATE TO MODERATE WIND EVENT (MON-WED 27TH-29TH). HOWEVER, IT
IS STILL PRETTY FAR OUT AND CONFIDENCE IS VERY LOW AT THIS TIME.
AVIATION
20/0056Z.
AROUND 00Z, THE MARINE LAYER DEPTH WAS AROUND 600 FEET DEEP AT
KLAX. THE TOP OF THE MARINE INVERSION WAS NEAR 1400 FEET WITH A
TEMPERATURE AROUND 23 DEGREES CELSIUS.
HIGH CONFIDENCE IN THE CURRENT FORECAST FOR VALLEY AND DESERT
TERMINALS. MODERATE CONFIDENCE IN THE CURRENT FORECAST FOR
COASTAL TERMINALS. HIGHER CONFIDENCE EXISTS IN FLIGHT CATEGORIES.
LESS CONFIDENCE EXISTS IN TIMING.
THERE IS A HIGH TO LIKELY CHANCE OF VLIFR TO LIFR CONDITIONS AT
COASTAL TERMINALS AS EARLY AS 03Z, OTHERWISE VFR CONDITIONS ARE
EXPECTED. THE HIGHEST CHANCE OF VLIFR TO LIFR CONDITIONS WILL BE
FOR COASTAL TERMINALS NORTH OF POINT CONCEPTION. VFR CONDITIONS
SHOULD DEVELOP BETWEEN 16Z AND 18Z, BUT THERE IS A LOW CHANCE OF
MVFR VISIBILITIES LINGERING UNTIL AS LATE AS 22Z.
KLAX...THERE IS A 60 PERCENT CHANCE OF VLIFR TO LIFR CONDITIONS
AS EARLY AS 03Z, OR AS LATE AS 13Z. IF VLIFR CONDITIONS WERE TO
DEVELOP, THE MOST LIKELY TIME PERIOD LOOKS TO BE BETWEEN 08Z AND
16Z. VFR CONDITIONS COULD DEVELOP AS SOON AS 17Z OR AS LATE AS
18Z. THERE IS A LOW CHANCE OF MVFR VISIBILITIES LINGERING UNTIL
22Z.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NO WIND
IMPACTS ARE EXPECTED AT THIS TIME.
MARINE
19/803 PM.
ACROSS THE OUTER WATERS, MODERATE CONFIDENCE IN THE FORECAST FOR
WINDS. GUSTS OF 21 TO 25 KNOTS ARE OBSERVED OVER THE WATERS
BETWEEN SAN NICOLAS ISLAND AND POINT CONCEPTION AND A SMALL CRAFT
ADVISORY (SCA) HAS BEEN ISSUED FOR PZZ673-676 THROUGH 3 AM MONDAY.
THERE IS A 40% CHANCE THAT THE GUSTS WILL SUBSIDE BELOW ADVISORY
LEVELS BEFORE THAT TIME, POSSIBLY AS EARLY AS MIDNIGHT.
OTHERWISE, A LONG PERIOD SWELL WILL CONTINUE TO BRING SEAS OF
7-9 FEET TO THE OUTER WATERS THROUGH TONIGHT, RISING TO 10 TO 11
FEET MONDAY INTO AT LEAST MID- WEEK, AND HIGHEST FOR NORTHERN
PORTIONS. THERE IS A 30 PERCENT CHANCE THAT A SCA WILL BE ISSUED
FOR THE OUTER WATERS ON MONDAY DUE TO HIGH SEAS. WINDS ARE
EXPECTED TO REMAIN BELOW SCA LEVELS MONDAY MORNING UNTIL
WEDNESDAY AFTERNOON, THEN NORTHWESTERLY WINDS WILL INCREASE SOUTH
OF POINT CONCEPTION AND ACROSS PORTIONS OF THE SOUTHERN INNER
WATERS, ESPECIALLY ACROSS THE SANTA BARBARA CHANNEL (40-60% CHANCE
OF SCAS BEING ISSUED). MODERATE CONFIDENCE IN SCA LEVEL WINDS
REACHING THE OUTER WATERS THURSDAY INTO FRIDAY, BUT THEN LIKELY
REMAINING SUB- ADVISORY ACROSS THE INNER WATERS.
PATCHY DENSE FOG IS POSSIBLE ACROSS PORTIONS OF THE COASTAL WATERS
TONIGHT INTO TOMORROW MORNING, WITH A CHANCE OF MORE WIDESPREAD
DENSE FOG DEVELOPING LATE TONIGHT.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT MONDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...HALL/BLACK
AVIATION...HALL
MARINE...LEWIS/SCHOENFELD/CC
SYNOPSIS...HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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