890  
FXUS66 KSGX 180448  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
948 PM PDT SAT OCT 17 2026  
   
SYNOPSIS  
 
WARM CONDITIONS WITH WEAK TO LOCALLY MODERATE SANTA ANA WINDS  
TODAY. COOLER CONDITIONS EXPECTED SUNDAY THROUGH THE UPCOMING  
WEEK. FOR THE MIDDLE TO END OF THE WEEK WESTERLY WINDS ARE  
EXPECTED TO INCREASE OVER THE MOUNTAINS AND DESERTS. INCREASING  
CHANCES FOR RAIN FROM THE COAST TO THE MOUNTAINS FOR WEDNESDAY AND  
THURSDAY.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
   
..UPDATED AVIATION DISCUSSION  
 
SANTA ANA WINDS HAVE WEAKENED SINCE THEIR PEAK YESTERDAY. OVER THE  
PAST 12 HOURS THE TOP 3 WIND GUSTS WERE 73 MPH AT HELLHOLE CANYON,  
71 MPH AT RANCHO HEIGHTS, AND 70 MPH AT FREEMONT CANYON. LINGERING  
GUSTS IN THE 35 TO 55 MPH RANGE CAN BE EXPECTED THROUGH THE  
AFTERNOON MOSTLY IN PLACES PRONE TO EASTERLY WINDS. WINDS WILL  
BECOME MORE CONFINED TO WIND PRONE LOCATIONS INTO THE EVENING AND  
OVERNIGHT HOURS. ABOVE AVERAGE TEMPERATURES CAN BE EXPECTED WEST  
OF THE MOUNTAINS TODAY, WITH BELOW AVERAGE TEMPERATURES IN THE  
DESERTS. HIGHS SUNDAY WILL RUN 3 TO 7 DEGREES COOLER FOR THE COAST  
AND 2 TO 4 DEGREES WARMER FOR INLAND LOCATIONS. THAT COOLING WILL  
SPREAD INLAND THROUGH TUESDAY. BY TUESDAY, MOST LOCATIONS WILL  
SEE BELOW AVERAGE TEMPERATURES.  
 
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT A CLOSED LOW WILL DIG SOUTH  
ALONG THE WEST COAST MONDAY AND TUESDAY, BEFORE SWINGING EAST INTO  
SOUTHERN CALIFORNIA TUESDAY NIGHT OR WEDNESDAY. IN ADDITION TO  
COOLER CONDITIONS, THIS LOW WILL BRING AN INCREASE IN WESTERLY WINDS  
AND RAIN CHANCES. WINDS MAY BEGIN TO INCREASE TUESDAY AFTERNOON,  
PEAKING WEDNESDAY OR THURSDAY OVER THE MOUNTAINS AND INTO THE  
DESERTS.  
 
RAIN CHANCES ARE IN THE FORECAST AS EARLY TUESDAY EVENING FOR SOME  
LOCATIONS, BUT THE MOST LIKELY TIME FOR PRECIPITATION LOOKS TO BE  
THIS WEDNESDAY AND THURSDAY. RIGHT NOW, MAINLY LIGHT TO MODERATE  
PRECIPITATION IS EXPECTED. ON THURSDAY AS THE LOW MOVES DIRECTLY  
OVER SOUTHERN CALIFORNIA IT WILL BRING IT'S ASSOCIATED VORTICITY  
WITH IT, INCREASING THE INSTABILITY OF THE ATMOSPHERE. THIS  
INTRODUCES A 10 TO 15 PERCENT CHANCE OF THUNDERSTORMS IN THE COASTAL  
BASIN. IF THUNDERSTORMS DEVELOP, LOCALLY HEAVY RAIN WILL OCCUR. MOST  
PLACES IN AND WEST OF THE MOUNTAINS HAVE A 50 TO 70% CHANCE OF  
RAINFALL TOTALS EXCEEDING 0.50", WITH THE SAN BERNARDINO MOUNTAINS  
HAVING A HIGHER CHANCE AND AREA DESERTS A LESSER CHANCE. THE PLACE  
WITH THE HIGHEST CHANCES OF SEEING 1" OR MORE OF RAIN IS THE SAN  
BERNARDINO MOUNTAINS. OVERALL, CONFIDENCE IN RAIN OCCURRING IS HIGH  
WITH MODERATE CONFIDENCE IN THE DETAILS.  
 
 
   
AVIATION  
 
180600Z...EASTERLY OFFSHORE WINDS HAVE LARGELY SUBSIDED AT THE  
SURFACE, THOUGH ELEVATED EASTERLY WINDS REMAIN POSSIBLE NEAR THE IN  
THE MOUNTAINS AND AT 4000-8000FT INTO THE EARLY OVERNIGHT HOURS.  
 
OTHERWISE...VFR CONDITIONS EXPECTED WITH SCT-BKN HIGH CLOUDS AOA  
10,000FT MSL THROUGH THIS EVENING. HIGH CLOUDS SCATTER OUT ACROSS  
THE AREA TONIGHT, WITH SKC THEREAFTER.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH WEDNESDAY.  
 
 
   
BEACHES  
 
ELEVATED SURF WILL CONTINUE THIS WEEKEND INTO MID-NEXT WEEK WITH  
MULTIPLE SOUTH SWELLS MOVING IN THROUGH THIS PERIOD. SURF INCREASES  
SLIGHTLY SUNDAY, WITH SURF 3 TO 6 FEET AND LOCAL SETS TO 7 FEET  
ALONG SOUTH AND SOUTHWEST-FACING BEACHES THROUGH AT LEAST WEDNESDAY.  
 
WHILE SURF AND RIP CURRENTS WILL BE ELEVATED, DAILY HIGH TIDES WILL  
NOT BE PARTICULARLY HIGH, AND THE THREAT OF COASTAL FLOODING IS  
MINIMAL.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...HIGH WIND WARNING UNTIL MIDNIGHT PDT TONIGHT FOR RIVERSIDE  
COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO  
PASS NEAR BANNING.  
 
PZ...NONE.  
 
 
 
 
 
PUBLIC...CO  
AVIATION/MARINE/BEACHES...MUNYAN  
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