126  
FXUS66 KLOX 240017  
AFDLOX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
517 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)
 
23/218 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 EVEN SLIGHTLY BELOW.  
 

 
   
AVIATION
 
24/0016Z.  
 
AT 2346Z AT KLAX, THE MARINE LAYER WAS 2700 FEET DEEP. THE TOP OF  
THE INVERSION WAS AROUND 4800 FEET WITH A TEMPERATURE OF 13 C.  
 
HIGH CONFIDENCE IN TAFS FOR KPMD AND KWJF.  
 
MODERATE CONFIDENCE IN REMAINING TAFS. FLIGHT CAT CHANGES MAY BE  
OFF BY +/- 2 HOURS. THERE IS A 25% CHANCE FOR IFR CIGS AT KPRB,  
KSBP, KSMX. BETTER CONFIDENCE IN CLEARING FCST FOR SITES THURSDAY  
AFTERNOON.  
 
KLAX...MODERATE CONFIDENCE IN TAF. LOW CLOUDS MAY REFORM AS EARLY  
AS 05Z OR AS LATE AS 09Z. THERE IS A 30% CHANCE OF CIGS REMAINING  
AOA 022. THERE IS A 15% CHANCE OF AN EAST WIND COMPONENT REACHING  
8 KT FROM 11Z-17Z.  
 
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 30% CHANCE OF NO  
CLEARING. THERE IS A 30% CHANCE OF CIGS REMAINING AOA 022.  
 

 
   
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...RORKE  
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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