203  
FXUS66 KSGX 151852  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
1152 AM PDT TUE SEP 15 2026  
   
SYNOPSIS  
 
AREA TEMPERATURES WILL BE UP TO 10 DEGREES BELOW AVERAGE THROUGH  
THURSDAY AS AN AREA OF LOW PRESSURE MOVES OVER THE AREA. THIS  
PATTERN WILL BRING NIGHT AND MORNING LOW CLOUDS FOR AREAS WEST OF  
THE MOUNTAINS WITH BREEZY WINDS ACROSS THE DESERT SLOPES AND DESERTS  
EACH DAY. A TROUGHING PATTERN WILL REMAIN INTO THE WEEKEND AND EARLY  
NEXT WEEK, WHERE TEMPERATURES WILL RISE CLOSER TO NORMAL.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
AN AREA OF LOW PRESSURE IS BEGINNING TO FORM NEAR SEATTLE AND  
VANCOUVER. THIS SYSTEM WILL WORK ITS WAY SOUTHWARD THROUGH THURSDAY,  
BRINGING IN COOLER THAN AVERAGE TEMPERATURES, BREEZY CONDITIONS  
ACROSS THE MOUNTAINS AND DESERTS, AND A HEALTHIER MARINE LAYER. LOW  
CLOUDS WILL FILL IN MUCH OF THE COASTAL BASIN EACH NIGHT AND MORNING  
WITH PATCHY FOG ON HIGHER TERRAIN. MODELS HINT THAT THE ATMOSPHERE  
MAY BE MOIST ENOUGH TO PRODUCE SOME AREAS OF DRIZZLE WEDNESDAY  
MORNING WITHIN 10-15 MILES OF THE COAST.  
 
MODELS PINPOINT THE LOW MOVING AS FAR AS NORTHERN CALIFORNIA BY  
THURSDAY. THIS WILL BRING TEMPERATURES DOWN NEAR 5 TO 10 DEGREES  
BELOW NORMAL FOR INLAND AREAS. CHANCES CONTINUE TO INCREASE TO SEE  
HIGHS NEAR 85 OR COOLER FOR AREAS OF THE HIGH DESERT, INLAND EMPIRE  
AND INLAND SAN DIEGO CO VALLEYS ON WEDNESDAY AND THURSDAY. SEA  
BREEZE WINDS WILL INCREASE OVER DESERT PASSES AND DESERTS AS WELL  
EACH AFTERNOON, PRIMARILY BETWEEN 20 AND 40 MPH.  
 
THE LOW LIFTS OUT OF THE STATE AND INTO THE NORTHERN ROCKIES BY  
FRIDAY INTO THE WEEKEND. THIS WILL LEAD TO SUBTLE WARMING BY FRIDAY  
INTO SATURDAY AS A QUICK AND WEAK AREA OF HIGH PRESSURE NUDGES INTO  
THE REGION. HIGH TEMPERATURES WILL RESPOND BY INCREASING SLIGHTLY  
AND EMERGING CLOSER TO NORMAL BY SATURDAY. MODELS ARE BEGINNING TO  
COME INTO BETTER AGREEMENT OF A WEAKER AREA OF LOW PRESSURE MOVING  
OVER THE AREA BY EARLY NEXT WEEK. THIS WOULD BEGIN TO COOL THE  
REGION BY A FEW DEGREES, GIVING US NEAR TO SLIGHTLY BELOW AVERAGE  
TEMPERATURES ONCE AGAIN.  
 
 
   
AVIATION  
 
151800Z...COAST/VALLEYS...REMAINING LOW CLOUDS OVER COASTAL AREAS  
WILL CLEAR OUT WITHIN THE NEXT HOUR OR SO. SKC AND VFR FOR THIS  
AFTERNOON. LOW CLOUDS BASED 1900-2400 FT MSL PUSH BACK ASHORE 00-02Z  
WED IN SAN DIEGO COUNTY AND 02-04Z IN ORANGE COUNTY. CLOUDS QUICKLY  
FILL THE COASTAL BASIN OVERNIGHT. PATCHY DRIZZLE FOR COASTAL SITES  
EARLY WED MORNING WITH INTERMITTENT MINOR CIG/VIS REDUCTIONS  
POSSIBLE. CLOUDS SCATTER BACK TO THE COASTLINE 16-19Z, THOUGH PATCHY  
LOW CLOUDS MAY LINGER THROUGH WED AFTERNOON NEAR THE COAST.  
 
MOUNTAINS/DESERTS...MOSTLY CLEAR AND VFR CONDITIONS TODAY AND  
TONIGHT.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SATURDAY.  
 
 
   
SKYWARN  
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
PUBLIC...APR  
AVIATION/MARINE...KW  
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