381
FXUS66 KLOX 251954
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1254 PM PDT FRI APR 25 2025
SYNOPSIS
25/1202 PM.
AN UPPER LOW AND FRONTAL SYSTEM WILL BRING RAIN TO THE AREA
SATURDAY WITH SNOW ABOVE 5000 FEET. HIGHS WILL BE 10 TO 25 DEGREES
BELOW NORMAL. DRY AND WARMER WEATHER IS EXPECTED SUNDAY THROUGH
NEXT WEEK THOUGH TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL
IN MOST AREAS.
SHORT TERM (TDY-MON)
25/1253 PM.
AN UNSEASONABLY COLD UPPER LOW WILL MOVE INTO THE AREA LATER
TONIGHT AND SATURDAY. MOST OF THE MODEL SOLUTIONS HAVE THE LOW
MOVING ONSHORE NEAR LOMPOC SATURDAY MORNING, THEN FOLLOWING THE
TRANSVERSE RANGE EAST BEFORE EXITING LA COUNTY SATURDAY EVENING.
AS THE UPPER LOW APPROACHES TONIGHT THE COLD FRONT WILL PIVOT AND
TAKE ON A NORTHWEST TO SOUTHEAST ORIENTATION. THIS WILL RESULT IN
THE RAIN ARRIVING AT A SIMILAR TIME, ROUGHLY BETWEEN 4 AND 7AM
FROM SLO COUNTY DOWN THROUGH VENTURA COUNTY. THEN MOVING INTO LA
COUNTY BETWEEN 8 AND 10AM. RAIN TOTALS HAVE BEEN NUDGED UPWARD
SLIGHTLY WITH AMOUNTS UP TO AROUND .80" IN THE FOOTHILLS AND
MOUNTAINS AND BETWEEN A QUARTER AND HALF INCH ELSEWHERE. MOST OF
THE MORNING RAIN IS EXPECTED TO BE ON THE LIGHTER SIDE, GENERALLY
A TENTH OF AN INCH PER HOUR OR LESS. HOWEVER, AS THE UPPER LOW
MOVES INLAND AND COLDER AIR MOVES INTO THE REGION SATURDAY
AFTERNOON, THE STEADY LIGHT RAIN IN THE MORNING WILL CHANGE TO A
SHOWERY PATTERN AS THE AIR MASS DESTABILIZES. WHILE SOME AREAS
MAY RECEIVE MINIMAL ADDITIONAL RAIN IN THE AFTERNOON, THE
INSTABILITY ALOFT WILL CREATE STRONGER UPLIFT AND A POSSIBILITY OF
SOME HEAVIER SHOWERS AND POSSIBLY EVEN AN THUNDERSTORM. HI RES
MODELS CONTINUE TO INDICATE PEAK RAIN RATES AROUND A QUARTER INCH
PER HOUR, SO AT THIS TIME THERE IS NO CONCERN FOR ANY BURN AREA
DEBRIS FLOWS WITH THIS STORM. WHILE THUNDERSTORMS CAN'T BE RULED
OUT ANYWHERE, THE MOST UNSTABLE AIR WILL BE ACROSS THE INTERIOR,
FROM THE MOUNTAINS AND NORTH AND EAST.
WITH THE UPTICK IN RAIN AMOUNTS, ESPECIALLY IN THE MOUNTAINS, A
WINTER WEATHER ADVISORY HAS BEEN ISSUED ABOVE 5000 FEET THROUGH
SATURDAY EVENING WITH SNOW TOTALS UP TO 6 INCHES. AT THIS TIME
SNOW IS NOT EXPECTED TO ACCUMULATE ON THE GRAPEVINE OVER
INTERSTATE 5, HOWEVER IT IS POSSIBLE THAT CONVECTIVE SHOWERS WITH
STRONG UPDRAFTS COULD RESULT IN SNOW REACHING THE SURFACE WITH
TEMPERATURES ABOVE FREEZING AS LOW AS 3500-4000 FEET.
RAIN AND SNOW IS EXPECTED TO TAPER OFF BY SATURDAY EVENING (IF NOT
BEFORE) WITH DRY WEATHER SUNDAY INTO EARLY NEXT WEEK. GUSTY WEST
TO NORTHWEST WINDS EXPECTED SUNDAY AFTERNOON, ESPECIALLY NEAR THE
COAST. TEMPERATURES WILL TREND WARMER BOTH DAYS, BUT MORE SO
INLAND, THOUGH WILL STILL BE AT LEAST 3-6 DEGREES BELOW NORMAL.
LONG TERM (TUE-FRI)
25/1253 PM.
THE WARMING TREND WILL CONTINUE THROUGH TUESDAY WITH SOME WARMER
VALLEYS GETTING INTO THE LOWER 80S WHILE COASTAL AREAS ARE IN THE
UPPER 60S TO MID 70S. MODELS SHOW ONSHORE INCREASING WEDNESDAY
THROUGH FRIDAY LEADING TO COOLER TEMPERATURES AND A LIKELY RETURN
OF THE MARINE LAYER.
AVIATION
25/1740Z.
AT 1714Z AT KLAX, THE MARINE LAYER WAS AROUND 5600 FT DEEP. THE
TOP OF THE INVERSION WAS AROUND 7000 FT WITH A TEMPERATURE OF 3
C.
HIGH CONFIDENCE IN RAIN OCCURING AT ALL SITES, BUT MODERATE
CONFIDENCE IN TIMING. ONSET OF RAIN MAY BE OFF BY +/- 3 HOURS.
MINIMUM FLIGHT CAT MAY BE OFF BY ONE CAT DURING RAINFALL AS VSBYS
MAY BOUNCE AROUND FREQUENTLY. PERIODS OF MODERATE RAIN IS
POSSIBLE DURING FRONTAL PASSAGE.
KLAX...MODERATE CONFIDENCE IN TAF. TIMING OF ONSET OF RAIN MAY BE
OFF +/- 3 HOURS. VSBYS 1SM-5SM POSSIBLE DURING RAINFALL. PERIODS
OF MODERATE RAIN POSSIBLE, ESPECIALLY BETWEEN 16Z AND 20Z,
WHICH MAY YIELD LOWEST VSBYS. THERE IS A MODERATE CHANCE FOR AN
EAST WIND COMPONENT REACHING 8 KTS FROM 12Z TO 18Z.
KBUR...MODERATE CONFIDENCE IN TAF. TIMING OF RAIN MAY BE OFF +/- 3
HOURS AND VSBYS OF 1SM-5SM ARE POSSIBLE DURING RAINFALL. MODERATE
RAIN IS POSSIBLE BETWEEN 16Z AND 20Z.
MARINE
25/1247 PM.
MODERATE CONFIDENCE IN FORECAST.
FOR THE OUTER WATERS, SMALL CRAFT ADVISORY (SCA) CONDS ARE NOT
EXPECTED TODAY. THEN, THERE IS A 20% CHANCE OF SCA LEVEL W-NW WIND
GUSTS LATE OVERNIGHT FRI INTO SAT FOR WESTERN PORTIONS OF
PZZ673/676. THERE IS A 30% CHANCE OF SCA LEVEL WIND GUSTS FOR
WESTERN PORTIONS OF PZZ676 DURING AFTERNOON/EVE HOURS ON SAT.
WIDESPREAD CHANCES FOR SCA CONDS INCREASE (60-90%) SUN AFTERNOON
THRU TUES NIGHT.
FOR THE INNER WATERS NORTH OF POINT SAL, CONDITIONS ARE EXPECTED
TO REMAIN BELOW SCA CRITERIA THROUGH TONIGHT, THEN A 30-40%
CHANCE SAT AFTERNOON/EVE. POTENTIAL FOR WIDESPREAD SCA WINDS
INCREASES DURING AFTERNOON/EVE HOURS SUN THRU TUES (50-80%
CHANCE).
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, CONDITIONS ARE
EXPECTED TO REMAIN BELOW SCA LEVELS THROUGH TONIGHT. THERE IS A
30-40% CHANCE OF SCA LEVEL WINDS ACROSS THE SANTA BARBARA CHANNEL
DURING THE AFTERNOON/EVE HOURS ON SAT. THEREAFTER, CHANCES
INCREASE TO >80% ACROSS THE SBA CHANNEL AND SOUTHERN INNER WATERS
OFF THE LA AND OC COASTS ON SUNDAY, INCLUDING NEARSHORE. THERE IS
A 50-60% CHANCE OF SCA LEVEL WINDS FOR WESTERN PORTIONS OF SBA
CHANNEL MON AFTERNOON/EVE. MUCH LOWER CHANCES ON TUE.
ACROSS THE WATERS, RAIN IS FORECAST TO BEGIN AS EARLY AS TONIGHT
AND IMPACT THE WATERS THROUGH AT LEAST SAT NIGHT. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS SAT IN THE INNER AND OUTER WATERS
ALONG THE CENTRAL COAST. ANY THUNDERSTORM COULD PRODUCE GUSTY,
ERRATIC WINDS, LIGHTNING, AND SMALL HAIL.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WINTER WEATHER ADVISORY IN EFFECT FROM 7 AM TO 11 PM PDT
SATURDAY FOR ZONES 353-376-377. (SEE LAXWSWLOX).
WINTER WEATHER ADVISORY IN EFFECT FROM 9 AM TO 11 PM PDT
SATURDAY FOR ZONES 378>380. (SEE LAXWSWLOX).
PZ...NONE.
PUBLIC...MW
AVIATION...LEWIS
MARINE...LEWIS
SYNOPSIS...MW/DB
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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