813  
FXUS66 KSGX 022026  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
126 PM PDT THU OCT 2 2025  
   
SYNOPSIS
 
 
COOLER CONDITIONS WITH AN UPTICK IN WINDS IN THE MOUNTAINS AND  
DESERTS FRIDAY. IN ADDITION, THE MARINE LAYER WILL DEEPEN WITH LOW  
CLOUDS EXPECTED TO SPREAD INTO PORTIONS OF THE INLAND VALLEYS FOR  
TONIGHT AND FRIDAY NIGHT. SLIGHTLY WARMER SATURDAY WEST OF THE  
MOUNTAINS WITH WEAK OFFSHORE FLOW. COOLER CONDITIONS EXPECTED SUNDAY  
AND MONDAY WITH WARMING NEXT TUESDAY THROUGH THURSDAY.  
 

 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
 
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
A TROUGH OF LOW PRESSURE IS EXPECTED TO MOVE INTO CALIFORNIA ON  
FRIDAY AND EAST INTO NEVADA ON SATURDAY. THIS WILL BRING 3 TO 7  
DEGREES OF COOLING TO INLAND AREAS ON FRIDAY, WITH AN INCREASE IN  
WINDS FOR THE MOUNTAINS AND DESERTS. WINDS WILL PEAK IN STRENGTH  
FRIDAY AFTERNOON AND EVENING. WIND GUSTS 35 TO 50 MPH EXPECTED  
OVERALL, WITH THE POTENTIAL FOR GUSTS UP TO 55 MPH IN PORTIONS OF  
THE SAN DIEGO DESERTS AND UP TO 60 MPH THROUGH THE SAN GORGONIO  
PASS. ADDITIONALLY, WITH THE INCREASE IN ONSHORE FLOW THE MARINE  
LAYER IS EXPECTED TO DEEPEN. AREAS OF LOW CLOUDS ARE EXPECTED TO  
REACH INTO THE VALLEYS FOR TONIGHT INTO FRIDAY MORNING.  
 
AS THE UPPER LEVEL LOW MOVES OVER NEVADA SATURDAY, THE OVERALL FLOW  
WILL QUICKLY SWITCH TO OFFSHORE EARLY SATURDAY MORNING. THE  
NORTH/NORTHEASTERLY WINDS ASSOCIATED WITH THE OFFSHORE FLOW ARE  
EXPECTED TO BE FAIRLY WEAK AND LOCALIZED TO THE SAN BERNARDINO AND  
SANTA ANA COASTAL MOUNTAIN SLOPES. WHILE THE MARINE LAYER WILL STILL  
BE FAIRLY DEEP, ANY LOW CLOUDS THAT DEVELOP FRIDAY NIGHT INTO  
SATURDAY ARE EXPECTED TO CLEAR FAIRLY QUICKLY IN THE INLAND EMPIRE  
AND ORANGE COUNTY. HIGHS ON SATURDAY ARE EXPECTED TO BE A FEW  
DEGREES WARMER THAN FRIDAY WEST OF THE MOUNTAINS, LIKELY DUE TO THE  
WEAK OFFSHORE FLOW. TEMPERATURES IN THE DESERTS WILL CONTINUE TO  
COOL A FEW DEGREES INTO SATURDAY.  
 
A BROAD TROUGH OF LOW PRESSURE WILL SET UP OVER THE WESTERN UNITED  
STATES ON SUNDAY. THIS WILL RESULT IN A FEW DEGREES OF COOLING WEST  
OF THE MOUNTAINS, WITH ADDITIONAL COOLING EXPECTED INTO MONDAY FOR  
MOST LOCATIONS. FOR NEXT TUESDAY AND WEDNESDAY, THE PATTERN BECOMES  
A LITTLE MORE UNCERTAIN WITH ENSEMBLE GUIDANCE STRUGGLING TO PIN  
DOWN THE AMPLITUDE AND POSITION OF THE AFOREMENTIONED TROUGH. THE  
SOLUTIONS WITH A DEEPER TROUGH OVER CALIFORNIA WOULD CONTINUE THE  
COOLER CONDITIONS WHILE THE SOLUTIONS WITH THE TROUGH TO OUR EAST  
WITH WEAK RIDGING OVER CALIFORNIA WOULD BRING SLIGHTLY WARMER  
CONDITIONS. CURRENT FORECAST FOLLOWS THE NBM WHICH LEANS TOWARDS THE  
WARMER SOLUTIONS FOR NEXT TUESDAY THROUGH THURSDAY.  
 

 
   
AVIATION
 
 
022015Z....COASTS/VALLEYS...LOW CLOUDS WILL REDEVELOP AFTER 03Z FOR  
THE COASTAL AREAS INITIALLY, AND THEN BEGIN TO FILL IN FROM WEST TO  
EAST, MAINLY AFTER 08Z FOR THE INLAND AREAS TONIGHT INTO FRIDAY  
MORNING. BASES SHOULD BE AROUND 1500 FEET MSL, RISING OVER 2000 FEET  
MSL EARLY FRIDAY, FILLING MUCH OF THE COASTAL BASIN. THEY WILL BEGIN  
TO SCATTER OUT BEGINNING AROUND 16-17Z FOR THE INLAND AREAS, AND  
THEN ERODING AWAY FROM EAST TO WEST TO THE COASTAL AREAS BY AROUND  
18-19Z SATURDAY. SOME OF THE CIGS OVER THE INNER WATERS COULD INVADE  
PORTIONS OF THE SAN DIEGO COUNTY, AND ORANGE COUNTY COASTLINE DURING  
THE AFTERNOON TOMORROW. CLOUDS WILL CONTINUE TO FILL BACK IN AND  
BECOME OVERCAST ALONG THE COAST BEGINNING AROUND 01-03Z SATURDAY,  
THEN FILLING BACK IN FROM WEST TO EAST, WITH SLIGHTLY LOWER BASES.  
 
MOUNTAINS/DESERTS...MOSTLY CLEAR AND VFR CONDITIONS TONIGHT AND  
TOMORROW.  
 

 
   
MARINE
 
 
NORTHWEST WINDS FRIDAY AFTERNOON AND EVENING OVER THE OUTER WATERS  
NEAR SAN CLEMENTE ISLAND WILL LIKELY LEAD TO HAZARDOUS CONDITIONS  
FOR SMALL CRAFT, AS WINDS ARE EXPECTED TO PERIODICALLY EXCEED 25  
KTS. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH  
MONDAY.  
 

 
   
SKYWARN
 
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 

 
   
SGX WATCHES/WARNINGS/ADVISORIES
 
 
CA...WIND ADVISORY FROM 4 PM FRIDAY TO 5 AM PDT SATURDAY FOR SAN  
DIEGO COUNTY DESERTS.  
 
WIND ADVISORY FROM 6 AM FRIDAY TO 5 AM PDT SATURDAY FOR SAN  
GORGONIO PASS NEAR BANNING.  
 
PZ...SMALL CRAFT ADVISORY FROM 11 AM TO 11 PM PDT FRIDAY FOR WATERS  
FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 10 TO  
60 NM OUT INCLUDING SAN CLEMENTE ISLAND.  
 

 
 

 
 
PUBLIC...CO  
AVIATION/MARINE...STEWEY  
 
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