781
FXUS66 KLOX 232117
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
217 PM PDT WED APR 23 2025
SYNOPSIS
23/926 AM.
A PERSISTENT MARINE LAYER WITH STRONGER ONSHORE FLOW WILL KEEP A
COOLER WEATHER PATTERN IN PLACE THROUGH SATURDAY. NIGHT THROUGH
MORNING LOW CLOUDS AND FOG WITH DRIZZLE WILL BE A STAPLE OF THE
FORECAST WITH CLOUDS STRUGGLING TO CLEAR FROM BEACHES EACH DAY.
GUSTY ONSHORE WINDS ARE POSSIBLE ACROSS THE INTERIOR PORTIONS OF
THE AREA THROUGH THE END OF THE WEEK. A WARMING TREND IS EXPECTED
FOR NEXT WEEK.
SHORT TERM (TDY-SAT)
23/203 PM.
NO REAL CHANGE IN THE FORECAST THROUGH THE WEEK AS A TROUGH OF LOW
PRESSURE MAINTAINS COOL CONDITIONS ALONG WITH LOTS OF MARINE LAYER
STRATUS. THE MARINE LAYER DEPTH ROSE TO 4000 FEET THIS MORNING
ACROSS THE LA BASIN AND ONLY SLIGHTLY LOWER ALONG THE CENTRAL
COAST. IN THEORY TOMORROW WILL BE ALMOST A CARBON COPY OF TODAY AS
FORECAST SOUNDINGS INDICATE LITTLE CHANGE IN THE MARINE LAYER
DEPTH AND ONSHORE GRADIENTS. TEMPERATURES AGAIN MOSTLY IN THE
LOWER 60S FOR COAST/VALLEYS AND LOW TO MID 70S IN THE DESERTS,
WHICH IS 5-10 DEGREES COOLER THAN NORMAL. AND SOME AREAS OF
DRIZZLE OR LIGHT RAIN, ESPECIALLY NEAR THE FOOTHILLS SOUTH OF PT
CONCEPTION.
ON FRIDAY A SLIGHTLY DEEPER UPPER LOW WILL APPROACH THE BAY AREA
WITH EVEN COLDER AIR ALOFT THAT WILL PUSH THE MARINE LAYER UP TO
AT LEAST 5000 FEET AND POSSIBLY AS HIGH AS 7000 FEET. THE
ADDITIONAL RISING MOTION CREATED BY THE COLDER AIR ALOFT SHOULD
THEORETICALLY GENERATE MORE WIDESPREAD DRIZZLE OR LIGHT RAIN BUT
AT THE VERY LEAST IT WILL MAINTAIN A COOL AND CLOUDY PATTERN WITH
MINIMAL CHANCES OF SUNSHINE FOR COAST/VALLEYS. THE ONE EXCEPTION
COULD BE THE IMMEDIATE COASTAL AREAS IF A REVERSE CLEARING
SCENARIO DEVELOPS.
AS THAT UPPER LOW MOVES ONSHORE NEAR THE MONTEREY/SLO COUNTY
BORDER SATURDAY MORNING, CHANCES FOR LIGHT RAIN WILL INCREASE
AREA-WIDE. OFFICIAL NBM POPS ARE STILL ON THE LOWER SIDE AND
PROBABLY NOT REPRESENTATIVE OF THE ACTUAL CHANCES FOR RAIN DUE TO
HOW LIGHT IT WILL BE. VIRTUALLY ALL THE EPS AND NOW ALSO THE GEFS
ENSEMBLES ARE SHOWING AT LEAST SOME LIGHT MEASURABLE RAIN ACROSS
THE CENTRAL COAST SATURDAY MORNING. THIS PERCENTAGE DROPS TO
AROUND 75% ACROSS VENTURA COUNTY AND AROUND 40% FOR SOUTHERN LA
COUNTY AND 10-15% ACROSS THE ANTELOPE VALLEY. SOME AREAS,
ESPECIALLY EASTERN VENTURA AND LA COUNTIES MAY NOT ACTUALLY
RECEIVE MEASURABLE RAIN SATURDAY BUT THAT DOESN'T MEAN IT WON'T BE
DAMP FROM DRIZZLE.
IN ADDITION, WITH THE CLOSE PROXIMITY OF THE UPPER LOW, CAN'T RULE
OUT AN ISOLATED THUNDERSTORM ACROSS SLO COUNTY, PARTICULARLY THE
INTERIOR WHICH COULD SEE SOME SUNSHINE AND SURFACE HEATING IN
ADDITION TO THE INSTABILITY ALOFT. THERE ARE STILL A HANDFUL OF
EPS SOLUTIONS INDICATING AROUND A HALF INCH OF RAIN AND THIS COULD
BE IN PART FROM CONVECTIVE CELLS WITH HEAVIER RAIN RATES.
LONG TERM (SUN-WED)
23/212 PM.
THE UPPER LOW IS EXPECTED TO BE MOVING INTO NV SUNDAY MORNING BUT
TEMPERATURES WILL STILL BE 5-10 DEGREES BELOW NORMAL. SKIES MAY
STILL BE CLOUDY IN SOME AREAS SUNDAY MORNING BUT RAPIDLY RISING
HEIGHTS AND INCREASING SUBSIDENCE SHOULD CLEAR MOST AREAS OUT BY
AFTERNOON IF NOT SOONER.
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION INTO EARLY
NEXT WEEK BRINGING HIGH TEMPERATURES TO 3-6 DEGREES ABOVE NORMAL
IN MOST AREAS. THE ONE EXCEPTION MAY BE THE IMMEDIATE COAST WHERE
PERSISTENT ONSHORE FLOW AND COOL OCEAN TEMPS WILL KEEP
TEMPERATURES CLOSER TO NORMAL OR EVENT SLIGHTLY BELOW.
AVIATION
23/1732Z.
AT 1646Z AT KLAX, THE MARINE LAYER WAS 3700 FEET DEEP. THE TOP OF
THE INVERSION WAS AROUND 5000 FEET WITH A TEMPERATURE OF 12 C.
MODERATE TO HIGH CONFIDENCE IN TAFS. CLEARING TIMES FOR KSBP,
KSMX, KBUR, AND KVNY MAY BE OFF BY +/- 2 HOURS. MVFR TO VFR CIGS
WILL LINGER AT COASTAL SITES SOUTH OF POINT CONCEPTION TODAY, BUT
THERE IS A 20% CHANCE FOR ANY OF THESE SITES TO BRIEFLY SCATTER
OUT AFTER 20Z. THERE IS A 20-30% CHANCE FOR IFR CIGS AT KPRB,
KSBP, KSMX, KBUR, AND KVNY AFTER 02Z, HIGHEST CHANCES FOR KPRB,
KSBP, AND KSMX.
KLAX...MODERATE CONFIDENCE IN TAF. FLIGHT CAT MAY FLIP FROM MVFR
AND VFR FREQUENTLY THRU THIS EVENING AS CIGS BOUNCE BETWEEN
025-040. THERE IS A 20% CHANCE THAT CIGS WILL SCATTER OUT BETWEEN
20Z AND 02Z. THERE IS A 20% CHANCE OF AN EAST WIND COMPONENT
REACHING 8 KT FROM 11Z-17Z THU.
KBUR...MODERATE CONFIDENCE IN TAF. CIGS MAY ARRIVE LINGER UNTIL AS
LEAST AS 22Z OR CLEAR AS EARLY AS 20Z. THERE IS A 20% CHANCE FOR
OVC007-010 AFTER 04Z TONIGHT.
MARINE
23/150 PM.
IN THE OUTER WATERS, MODERATE CONFIDENCE IN THE FORECAST. WINDS
WILL BE CLOSE TO LOW-END SMALL CRAFT ADVISORY (SCA) LEVELS AT
TIMES THRU FRI NIGHT. SCA LEVEL WIND GUSTS ARE LIKELY (50-60%
CHANCE) ACROSS MUCH OF THE OUTER WATERS THIS AFTERNOON THROUGH
LATE TONIGHT. THERE IS A 20-40% CHANCE OF LOW-END SCA LEVEL WINDS
ANYWHERE ACROSS THE OUTER WATERS THU AFTERNOON THRU FRI NIGHT/SAT
MORNING. SCA LEVEL CONDS ARE LIKELY (70% CHANCE) SAT AFTERNOON
THRU MON NIGHT.
FOR THE INNER WATERS NORTH OF PT. SAL, MODERATE TO HIGH
CONFIDENCE IN THE FORECAST. THERE IS A 40% CHANCE OF SCA LEVEL
WINDS DURING THE AFTERNOON/EVE HOURS TODAY THRU FRI. SCA CONDS ARE
LIKELY (60% CHANCE) DURING THE AFTERNOON/EVE HOURS SAT THRU MON.
FOR THE INNER WATERS SOUTH OF PT. CONCEPTION, MODERATE CONFIDENCE
IN THE FORECAST. THERE IS A 50% CHANCE OF SCA LEVEL WINDS DURING
THE AFTERNOON/EVE HOURS TODAY AND A 40% CHANCE THURS THRU FRI IN
WESTERN PORTIONS OF THE SANTA BARBARA CHANNEL. THEN SCA CONDS ARE
LIKELY (60% CHANCE) DURING THE AFTERNOON/EVE HOURS SAT THRU MON.
THERE IS A 40% CHANCE FOR SCA LEVEL WINDS TO ENTER THE WESTERN
PORTION OF THE SOUTHERN INNER WATERS SUN AFTERNOON/EVE. OTHERWISE,
SCA CONDS ARE NOT EXPECTED THRU MON NIGHT.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR ZONE
381. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT THURSDAY FOR
ZONES 650-670-673-676. (SEE LAXMWWLOX).
PUBLIC...MW
AVIATION...LEWIS
MARINE...DB/LEWIS
SYNOPSIS...HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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