938  
FXUS66 KSGX 270402  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
902 PM PDT SAT JUL 26 2025  
   
SYNOPSIS  
 
A TROUGH ACROSS THE WEST COAST WILL CONTINUE COOLER THAN NORMAL  
WEATHER THROUGH THE WEEKEND. HIGH PRESSURE WILL EXPAND FURTHER  
WEST, BRINGING A WARMING TREND SUNDAY INTO TUESDAY, WITH  
TEMPERATURES STAYING NEAR AVERAGE THROUGH THE END OF NEXT WEEK.  
BREEZY WEST WINDS WILL CONTINUE THIS WEEKEND ACROSS MOUNTAINS AND  
DESERTS, WHILE THE MARINE LAYER PROVIDES LOW CLOUDS AT TIMES WEST  
OF THE MOUNTAINS.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
A FEW HIGH CLOUDS CONTINUE TO LIFT NORTHEAST ACROSS THE REGION  
THIS EVENING, AND LOW CLOUDS ARE DEVELOPING OFF THE COAST. THE 00Z  
KNKX SOUNDING SHOWS THE MARINE INVERSION BASED NEAR 2300 FT MSL,  
DEEP ENOUGH TO ALLOW LOW CLOUDS TO SPREAD INTO PARTS OF THE INLAND  
VALLEYS OVERNIGHT.  
 
UPPER LEVEL HIGH PRESSURE OVER THE SOUTHEAST US WILL SLOWLY SHIFT  
WESTWARD AND EXPAND INTO SOCAL THROUGH MIDWEEK, THEN THE UPPER  
LEVEL PATTERN REMAINS FAIRLY STAGNANT THROUGH THE END OF THE WEEK  
WITH THE HIGH CENTERED SOMEWHERE NEAR TX AND WEAK TROUGHING ALONG  
THE WEST COAST. THIS WILL BRING GRADUAL WARMING THROUGH WEDNESDAY  
WITH LITTLE DAY-TO-DAY VARIATION INTO NEXT WEEKEND. ON SUNDAY, HIGH  
TEMPERATURES WILL BE AROUND 7-12 DEGREES BELOW NORMAL IN THE  
MOUNTAINS AND VALLEYS, AND AROUND 3-5 DEGREES BELOW NORMAL NEAR  
THE COAST AND DESERTS. BY WEDNESDAY HIGHS WILL RETURN TO NEAR  
NORMAL, OR AROUND THE MID 70S TO LOW 80S FOR THE COASTAL AREAS,  
MID 80S TO MID 90S IN THE VALLEYS, 70S AND 80S IN THE MOUNTAINS,  
90S TO AROUND 100 IN THE HIGH DESERT, AND 105-110 IN THE LOW  
DESERTS. WITH THE TROUGH STILL IN THE VICINITY AND SOUTHWEST FLOW  
ALOFT PREVAILING, ENSEMBLES REMAIN PREDOMINANTLY DRY THROUGH THE  
END OF THE WEEK. A FEW MEMBERS FROM THE EPS AND GEFS HAVE AN  
INCREASE IN PRECIPITABLE WATER AS MONSOON MOISTURE TRIES TO SNEAK  
IN, BUT THEY ARE VERY MUCH IN THE MINORITY. AT THIS POINT THE  
CHANCE OF MOISTURE RETURNING IS LESS THAN 5% FOR THE REST OF THE  
WEEK. AND IN CASE YOU THOUGHT THIS MAY MEAN WE ARE FREE FROM NO  
SKY JULY, MARINE LOW CLOUDS WILL HOLD ON THROUGH THE WEEK, THOUGH  
CLOUDS WILL BECOME CONFINED TO THE COASTAL AREAS AS THE MARINE  
LAYER BECOMES MORE SHALLOW.  
 
 
   
AVIATION  
 
270300Z....COASTS/VALLEYS...LOW CLOUDS BASED 1800-2300 FT MSL ARE  
SLOWLY DEVELOPING OVER COASTAL WATERS. CLOUDS WILL OVERTAKE SAN  
DIEGO COUNTY IN THE NEXT FEW HOURS. SLOWLY FILLING INTO ORANGE  
COUNTY AROUND 09Z AND MOST OF THE INLAND EMPIRE BY 12Z.  
SCATTERING TO THE COAST BY 17-18Z. CLOUDS RETURN TO COASTAL AREAS  
AFTER 03Z WITH LOWER BASES 1200-1800 FT MSL.  
 
MOUNTAINS/DESERTS...MOSTLY CLEAR WITH VFR CONDITIONS THROUGH SUNDAY  
EVENING.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH THURSDAY.  
 
 
   
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...SS  
AVIATION/MARINE...KW  
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