790  
FXUS66 KLOX 210922  
AFDLOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
222 AM PDT TUE APR 21 2026  
   
SYNOPSIS
 
21/222 AM.  
 
LIGHT TO MODERATE RAIN IS EXPECTED THROUGH TODAY, ALTHOUGH  
LOCALLY HEAVIER RAIN IS POSSIBLE OVER THE NORTHERN AREA. THE  
HIGHEST RAIN AMOUNTS ARE EXPECTED FOR SAN LUIS OBISPO COUNTY,  
HOWEVER WITH MINIMAL IMPACTS. MUCH COOLER WEATHER IS ON TAP  
THROUGH WEDNESDAY. GUSTY SOUTHWEST WINDS ARE EXPECTED TODAY,  
FOLLOWED BY WEST TO NORTHWEST WINDS WEDNESDAY THROUGH FRIDAY.  
 

 
   
SHORT TERM (TDY-THU)
 
21/221 AM.  
 
A MODERATE LATE SEASON STORM WILL MOVE ACROSS SOUTHWEST CALIFORNIA  
THROUGH TODAY. MOST OF THE RAIN WILL OCCUR THIS MORNING THROUGH  
THIS EVENING, HOWEVER SOME LIGHT SHOWERS MAY LINGER OVER THE  
NORTHERN MOUNTAIN SLOPES TONIGHT INTO EARLY WEDNESDAY. THE  
HIGHEST RAIN AMOUNTS WILL COVER SAN LUIS OBISPO AND SANTA BARBARA  
COUNTIES, AS THE FRONT WILL WEAKEN AS IT MOVES OVER VENTURA COUNTY  
AND ESPECIALLY LOS ANGELES COUNTY. THERE WILL BE A SLIGHT CHANCE  
OF THUNDERSTORMS FROM 400 AM TODAY THROUGH THE AFTERNOON HOURS  
OVER SAN LUIS OBISPO COUNTY. WHILE THERE IS A CHANCE OF LOCALLY  
HEAVIER RAIN AT TIMES ACROSS MUCH OF THE AREA, THIS WILL BE  
ENHANCED OVER SLO COUNTY DUE TO THE CONVECTIVE CHANCES.  
 
RAINFALL TOTALS WILL RANGE FROM ONE QUARTER OF AN INCH TO AROUND AN  
INCH FOR SAN LOUIS OBISPO (EXCEPT FOR 1.5-2 INCHES FOR THE COASTAL  
HILLS) AND SANTA BARBARA COUNTIES, TO 0.5 INCH IN THE VENTURA  
MOUNTAINS, TO ONE THIRD OF AN INCH OR LESS ELSEWHERE. BRIEF  
HEAVY DOWNPOURS, GUSTY WINDS UP TO 40 MPH, AND CLOUD-TO- GROUND  
LIGHTNING ARE THE MOST LIKELY HAZARDS WITH ANY THUNDERSTORMS. PEAK  
RAINFALL RATES WILL BE AROUND A QUARTER OF AN INCH PER HOUR OR  
LESS, ALTHOUGH RATES UP TO 0.5 INCHES PER HOUR MANY OCCUR IN ANY  
THUNDERSTORMS OR ALONG THE FRONTAL BOUNDARY. MINOR FLOODING IS  
POSSIBLE IF THESE RATES OCCUR, ESPECIALLY IN LOW LYING URBAN  
AREAS OR NEAR RECENT BURN SCARS.  
 
AS FOR WINDS, GUSTY SOUTH TO SOUTHWEST WINDS ARE EXPECTED AHEAD OF  
AND NEAR THE FRONT, GENERALLY 20 TO 40 MPH. STRONGER SW WINDS  
WILL AFFECT THE ANTELOPE VALLEY AND SAN GABRIEL MOUNTAINS FROM  
AROUND 10 AM TODAY THROUGH THIS EVENING. AFTER THIS TIME, WINDS  
WILL SHIFT TO THE WEST TO NORTHWEST AND REMAIN GUSTY INTO  
THURSDAY. THESE WINDS WILL BE STRONGEST OVER THE MOUNTAINS AND  
INTERIOR, BUT MAY AFFECT SOME COASTAL SECTIONS AT TIMES.  
   
LONG TERM (FRI-MON)
 
20/1222 PM.  
 
NEAR NORMAL TEMPERATURES ARE EXPECTED FRIDAY WHEN MOST HIGHS WILL  
BE IN THE LOW TO MID 70S. THEN TEMPERATURES WILL FALL TO SEVERAL  
DEGREES BELOW NORMAL OVER THE WEEKEND, WITH HIGHS IN THE 60S  
COMMON. THERE IS A 30-50 PERCENT CHANCE OF MAINLY LIGHT RAIN  
FOCUSED ACROSS THE FOOTHILLS TO INTERIOR SOMETIME THIS WEEKEND  
THANKS TO MOIST UPSLOPE FLOW OVER THE MOUNTAINS AND LIMITED  
INSTABILITY. THE STORM ENERGY IS COMING FROM THE SOUTHWEST TO WEST  
AND IS WEAK SO SIGNIFICANT WIND CONCERNS ARE UNLIKELY, BUT IT DOES  
LEND ITSELF TO BELOW NORMAL FORECAST CONFIDENCE.  
 
AN ACTIVE PATTERN (FOR APRIL) MAY CONTINUE INTO EARLY NEXT WEEK  
AS ANOTHER WEAK STORM IS POSSIBLE.  
 

 
   
AVIATION
 
21/0919Z.  
 
AT 07Z AT KLAX, THE MARINE LAYER WAS 1500 FT WITH A WEAK INVERSION  
UP TO 2100 FT WITH A MAXIMUM TEMPERATURE OF 13 C.  
 
MODERATE TO LOW CONFIDENCE FROM NORTH TO THE SOUTH AS THE THE  
FRONT APPROACHES. TIMING OF RAIN AND FLIGHT CATEGORY CHANGES COULD  
BE +/- 3 HOURS OF CURRENT FORECASTS. THERE WILL BE A 10-15%  
CHANCE OF THUNDERSTORMS THROUGH 20Z TUE AT KPRB, KSBP, AND KSMX.  
 
KLAX...HIGH CONFIDENCE IN RETURN OF CIG/VSBY RESTRICTIONS, BUT  
TIMING OF FLIGHT CATEGORY CHANGES COULD BE +/- 3 HOURS OF CURRENT  
FORECASTS. TIMING OF LIGHT RAIN COULD ALSO BE +/- 3 HOURS OF  
CURRENT FORECAST. THERE IS A 30% CHANCE FOR AN EASTERLY WIND  
COMPONENT OF AROUND 5-6 KT FROM 13Z TO 18Z.  
 
KBUR...HIGH CONFIDENCE IN RETURN OF CIG/VSBY RESTRICTIONS, BUT  
TIMING OF FLIGHT CATEGORY CHANGES COULD BE +/- 3 HOURS OF CURRENT  
FORECASTS.  
 

 
   
MARINE
 
21/211 AM.  
 
FOR THE OUTER WATERS, MODERATE TO HIGH CONFIDENCE IN CURRENT  
FORECAST. AHEAD OF THE FRONT, THERE IS POTENTIAL FOR SHORT-LIVED  
SCA LEVEL WINDS THROUGH THIS MORNING, WITH BEST CHANCES FROM THE  
CHANNEL ISLANDS NORTHWARD. SEAS WILL BE NEAR 10 FEET THROUGH TODAY.  
FOR WEDNESDAY THROUGH FRIDAY, HIGH CONFIDENCE IN COMBINATION OF  
SCA LEVEL NORTHWESTERLY WINDS AND SEAS WITH A 20-30% CHANCE OF  
GALE FORCE WINDS SOUTH OF POINT CONCEPTION WEDNESDAY NIGHT. FOR  
SATURDAY, HIGH CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA  
LEVELS.  
 
FOR THE INNER WATERS NORTH OF POINT SAL, MODERATE TO HIGH  
CONFIDENCE IN CURRENT FORECAST. AHEAD OF THE FRONT, THERE IS  
POTENTIAL FOR SHORT-LIVED SCA LEVEL WINDS THROUGH THIS MORNING,  
WITH BEST CHANCES FROM THE CHANNEL ISLANDS NORTHWARD. SEAS WILL BE  
NEAR 10 FEET THROUGH TODAY. FOR WEDNESDAY THROUGH FRIDAY, THERE  
IS A 60-80% CHANCE OF SCA LEVEL NORTHWESTERLY WINDS, MAINLY IN THE  
AFTERNOON AND EVENING HOURS. ON SATURDAY, HIGH CONFIDENCE IN  
WINDS AND SEAS REMAINING BELOW SCA LEVELS.  
 
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, MODERATE TO HIGH  
CONFIDENCE IN CURRENT FORECAST. THIS MORNING, WINDS AND SEAS  
SHOULD MOSTLY REMAIN BELOW SCA LEVELS, BUT LOCALIZED GUSTS NEAR  
THE FRONT MAY BRIEFLY REACH SCA LEVELS. ON WEDNESDAY, HIGH  
CONFIDENCE IN SCA LEVEL NORTHWESTERLY ACROSS ALL THE SOUTHERN  
INNER WATERS WITH A 20% CHANCE OF GALE FORCE WINDS. FOR THURSDAY  
THROUGH FRIDAY, WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA  
LEVELS FOR MOST AREAS. THE ONLY EXCEPTION WILL BE THE WESTERN HALF  
OF THE SANTA BARBARA CHANNEL WITH A 60-80% CHANCE OF SCA LEVEL  
WINDS. ON SATURDAY, HIGH CONFIDENCE IN WINDS AND SEAS REMAINING  
BELOW SCA LEVELS FOR ALL OF THE SOUTHERN INNER WATERS.  
 
A COLD FRONT WILL SWEEP ACROSS THE COASTAL WATERS THROUGH TODAY.  
WITH THIS FRONTAL PASSAGE, THERE WILL BE A 20% CHANCE OF  
THUNDERSTORMS ACROSS THE COASTAL WATERS NORTH OF POINT CONCEPTION.  
ANY THUNDERSTORMS THAT DEVELOP MAY PRODUCE BRIEF HEAVY RAIN,  
GUSTY WINDS AND LOCALLY ROUGH SEAS.  
 

 
   
LOX WATCHES/WARNINGS/ADVISORIES
 
 
CA...WIND ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO 10 PM PDT  
THIS EVENING FOR ZONES 378>383. (SEE LAXNPWLOX).  
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 6 PM PDT THIS EVENING  
FOR ZONES 645-670. (SEE LAXMWWLOX).  
 

 
 

 
 
PUBLIC...CILIBERTI/SCHOENFELD  
AVIATION...SCHOENFELD  
MARINE...PHILLIPS/RAT  
SYNOPSIS...MW/RS/CC  
 
WEATHER.GOV/LOSANGELES  
 
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:  
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab CA Page Main Text Page