597  
FXUS66 KSGX 231911  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
1211 PM PDT WED SEP 23 2026  
   
SYNOPSIS  
 
IT WILL BE WARMER THROUGH SATURDAY WITH MODERATE HEATRISK ON  
FRIDAY AND SATURDAY FOR SOME COASTAL AND WESTERN VALLEY AREAS.  
THERE IS ALSO A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE  
MOUNTAINS ON THURSDAY AFTERNOON. A LOW PRESSURE SYSTEM MOVING  
INLAND ALONG THE WEST COAST AND MID AND HIGH CLOUDS FROM TROPICAL  
MOISTURE TO THE SOUTH WILL BRING COOLING FOR SUNDAY AND MONDAY.  
THEN WARMER UNDER HIGH PRESSURE FOR NEXT TUESDAY.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
   
..UPDATED AVIATION/MARINE/BEACHES DISCUSSION  
 
   
SHORT TERM (TODAY THROUGH FRIDAY)  
 
A WEAK UPPER LEVEL LOW PRESSURE SYSTEM OFF THE COAST OF NORTHERN  
BAJA WILL BRING WEAK EASTERLY WINDS TO THE MOUNTAINS FOR THIS  
MORNING AND AGAIN THURSDAY MORNING WITH GUSTS LESS THAN 25 MPH.  
THIS WILL ALSO BRING SOME MID-LEVEL MONSOONAL MOISTURE NORTHWARD  
INTO THE AREA FOR THIS AFTERNOON AND THURSDAY AFTERNOON WITH THE  
PRECIPITABLE WATER VALUES HIGHER ON THURSDAY. THIS WILL BRING SOME  
CLOUDS TO THE MOUNTAINS FOR THIS AFTERNOON AND A LESS THAN 20  
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS FOR  
THURSDAY AFTERNOON. THE HRRR ALSO SHOWS SOME CONVECTIVE  
DEVELOPMENT ALONG THE ELSINORE CONVERGENCE ZONE IN THE INLAND  
EMPIRE ON THURSDAY AFTERNOON. THIS WILL BE FOLLOWED BY SOME DRYING  
ON FRIDAY.  
 
HIGH TEMPERATURES TODAY WILL WARM AS MUCH AS 5 TO 10 DEGREES FOR  
THE INLAND VALLEYS WITH HIGH TEMPERATURES AS MUCH AS 4 TO 8  
DEGREES ABOVE AVERAGE FOR THE VALLEYS AND INLAND ORANGE COUNTY  
WITH HIGH TEMPERATURES WITHIN A FEW DEGREES OF AVERAGE ELSEWHERE.  
HIGH TEMPERATURES FOR TODAY WILL RANGE FROM THE MID 70S TO LOWER  
80S NEAR THE COAST TO THE 90S FOR THE INLAND EMPIRE WITH 100 TO  
104 FOR THE LOWER DESERTS. NOT MUCH CHANGE IS EXPECTED ON  
THURSDAY.  
 
ON FRIDAY, BOTH HIGH AND LOW TEMPERATURES WILL WARM SLIGHTLY WITH  
MODERATE HEATRISK FOR THE COASTAL AREAS AND PORTIONS OF THE  
WESTERN VALLEYS IN SAN DIEGO COUNTY AND IN PORTIONS OF INLAND  
ORANGE COUNTY.  
 
THE MARINE LAYER HAS DECREASED IN DEPTH TO AROUND 2500 FEET. IT  
WILL CONTINUE TO SLOWLY DECREASE IN DEPTH INTO FRIDAY WITH NIGHT  
AND MORNING COASTAL LOW CLOUDS NOT SPREADING INLAND PAST THE  
WESTERN VALLEYS.  
 
 
   
LONG TERM (SATURDAY THROUGH TUESDAY)  
 
FRIDAY NIGHT WILL BE SLIGHTLY WARMER WITH NOT MUCH CHANGE IN HIGH  
TEMPERATURES ON SATURDAY. MODERATE HEATRISK WILL CONTINUE ON  
SATURDAY FOR THE SAME AREAS AS ON FRIDAY, COASTAL AREAS AND  
PORTIONS OF THE WESTERN VALLEYS IN SAN DIEGO COUNTY AND IN  
PORTIONS OF INLAND ORANGE COUNTY.  
 
MID AND HIGH CLOUDS FROM TROPICAL MOISTURE AND A LOW PRESSURE  
SYSTEM MOVING INLAND ALONG THE WEST COAST WILL SPREAD COOLING  
INLAND ON SUNDAY AND MONDAY. HIGH TEMPERATURES ON SUNDAY WILL COOL  
A FEW DEGREES NEAR THE COAST TO AS MUCH AS 4 TO 8 DEGREES FOR THE  
INLAND VALLEYS WITH HIGH TEMPERATURES COOLING A FEW MORE DEGREES  
ON MONDAY. WITH THE COOLING, HIGH TEMPERATURES ON MONDAY WILL BE  
AS MUCH AS 5 DEGREES BELOW AVERAGE FOR THE MOUNTAINS, INLAND  
VALLEYS, AND HIGH DESERT. HIGH TEMPERATURES ON MONDAY WILL RANGE  
FROM THE 70S NEAR THE COAST TO THE 80S FOR THE INLAND EMPIRE WITH  
THE LOWER DESERTS IN THE MID 90S. ON TUESDAY, HIGH PRESSURE OVER  
SOUTHERN CALIFORNIA WILL BRING WARMING WITH DECREASING MID AND  
HIGH CLOUDS.  
 
ANY SURF IMPACTS TO THE COAST OF ORANGE AND SAN DIEGO COUNTIES  
FROM HURRICANE POLO WOULD MOST LIKELY BE AFTER THE WEEKEND. THE  
CURRENT TRACK FORECAST THROUGH THE WEEKEND WOULD MOST BE OUTSIDE  
OF THE THE SWELL WINDOW THE COAST OF ORANGE AND SAN DIEGO  
COUNTIES. THERE IS GREATER SPREAD IN THE TRACK FORECAST BEYOND THE  
WEEKEND AND ANY RESULTING POTENTIAL SWELL AND SURF IMPACTS ALONG  
THE COAST FOR EARLY NEXT WEEK.  
 
 
   
AVIATION  
 
231900Z...COAST/VALLEYS...LOW CLOUDS BASED 1000-1500 FEET MSL WILL  
GRADUALLY INCREASE AFTER 02Z THU, BECOMING RATHER UNIFORM AFTER 10Z.  
LOW CLOUDS ARE NOT EXPECTED TO REACH KONT/KSBD. LOW CLOUDS WILL  
SCATTER OUT 16-18Z THU.  
 
OTHERWISE...MOSTLY CLEAR SKIES WITH UNRESTRICTED VIS THROUGH THU.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.  
 
 
   
BEACHES  
 
THE COMBINATION OF A 3 FOOT SWELL FROM 190 DEGREES ON SUNDAY  
SHIFTING TO 160 DEGREES FOR MONDAY AND TUESDAY WITH A 12 TO 15  
SECOND PERIOD COINCIDING WITH OUR BIMONTHLY ELEVATED HIGH TIDES WILL  
INCREASE CHANCES FOR COASTAL FLOODING AND EROSION. PREDICTED HIGH  
TIDES OF 6.5 AND 7.0 FT MSL WILL OCCUR BETWEEN 10 AND 11 AM SUNDAY  
THROUGH TUESDAY. THE LISTED TIDE PREDICTIONS HAVE BEEN CORRECTED TO  
REFLECT CURRENT TRENDS IN ACTUAL TIDE OBSERVATIONS. SURF WILL BE  
ELEVATED, ESPECIALLY FOR SOUTH FACING BEACHES WITH SETS UP TO 5 FEET  
ON SUNDAY. SURF HEIGHTS AND DIRECTION OF THE SWELL REMAIN UNCERTAIN  
FOR MONDAY AND TUESDAY AND WILL BE MOST INFLUENCED BY THE TRACK OF  
TROPICAL CYCLONE POLO.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
PUBLIC...17  
AVIATION/MARINE/BEACHES...CO  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab CA Page
Main Text Page