057  
FXUS66 KSGX 302021  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
121 PM PDT SAT AUG 30 2025  
   
SYNOPSIS  
 
WARM AND DRY UNDER SUNNY SKIES THROUGH THE WEEKEND. HEAT PEAKS  
MONDAY/TUESDAY WITH SOME INLAND AREAS UNDER A HEAT ADVISORY.  
MONSOONAL MOISTURE RETURNS FOR TUESDAY INTO THE END OF NEXT WEEK,  
WITH CHANCES FOR STORMS IN THE MOUNTAINS AND DESERTS EACH  
AFTERNOON.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
IT'S A GORGEOUS, SUNNY DAY ACROSS SOUTHERN CALIFORNIA, THE PERFECT  
START TO A HOLIDAY WEEKEND. HIGH TEMPERATURES ACROSS THE INLAND  
REGIONS ARE SLIGHTLY ABOVE NORMAL, AROUND 2-5 DEGREES, WHILE THOSE  
ALONG THE COAST ARE A BIT MORE SEASONAL. IF YOU'RE HEADING TO THE  
BEACH THIS WEEKEND, AN UPTICK IN SOUTHERLY SWELL WILL LEAD TO  
ELEVATED SURF AND STRONG RIP CURRENTS AT MOST BEACHES THROUGH AT  
LEAST MONDAY, SO SWIM WITH CAUTION AND ALWAYS NEAR A LIFEGUARD.  
OTHER THAN THE SURF, TEMPERATURES WILL CONTINUE TO CLIMB INTO EARLY  
NEXT WEEK AS A ELONGATED RIDGE OVER THE CENTRAL CONUS AMPLIFIES,  
WITH THE THERMAL RIDGE AXIS SETTING UP OVER THE COLORADO RIVER  
VALLEY. BY MONDAY, 850MB TEMPS OF 28-30C OVER THE REGION SHOULD  
USHER IN HIGHS OF 110-112F FOR THE DESERTS AND 100-106F FOR THE  
INLAND EMPIRE. THE LACK OF A WIDESPREAD MARINE LAYER YESTERDAY AND  
TODAY HAS RESULTED IN WARMER THAN EXPECTED TEMPERATURES ACROSS  
THE VALLEYS AND COASTAL REGIONS, WITH LIMITED COOLING OVERNIGHT  
DUE TO THE STUBBORN MONSOONAL MOISTURE LEFT OVER FROM THE PAST  
WEEK. WITH THE BUILDING RIDGE, ANY RETURN OF THE MARINE LAYER WILL  
BE PATCHY AT BEST, AND LIMITED TO NEAR OR JUST OFF THE COAST INTO  
EARLY NEXT WEEK. GIVEN THE EXPECTED PATCHINESS, NO WIDESPREAD  
DENSE FOG IS CURRENTLY EXPECTED, BUT LOCALIZED AREAS OF VISIBILITY  
BELOW 2 MILES WON'T BE OUT OF THE QUESTION.  
 
HEAT WILL PEAK MONDAY/TUESDAY WITH TEMPERATURES 6-12 DEGREES ABOVE  
NORMAL ACROSS VALLEYS AND COASTAL TERRAIN/FOOTHILLS, AND A HEAT  
ADVISORY IS IN EFFECT FOR THESE AREAS. BY TUESDAY, MONSOONAL  
MOISTURE WILL SURGE NORTHWARD INTO THE MOUNTAINS AND DESERTS,  
LIMITING TEMPERATURES A BIT FOR THESE REGIONS. WITH AMPLE MID-  
LEVEL MOISTURE AND INSTABILITY, SHOWERS AND THUNDERSTORMS LOOK TO  
DEVELOP OFF THE MOUNTAINS TUESDAY AFTERNOON, SIMILAR TO WHAT WAS  
OBSERVED THIS PAST WEEK. A FEW STORMS WILL LIKELY MAKE IT OFF THE  
MOUNTAINS AND INTO THE URBAN PARTS OF THE COACHELLA VALLEY, WITH A  
LOWER CHANCE FOR SPILLOVER INTO THE INLAND EMPIRE OR SAN DIEGO  
VALLEYS. BRIEF, HEAVY RAINFALL, LIGHTNING, AND VERY GUSTY WINDS  
WILL ALL BE POSSIBLE NEAR ANY STORM.  
 
THE MONSOONAL MOISTURE MAY HANG AROUND FOR A BIT AS A LOW OFF THE  
COAST OF SAN FRANCISCO MOVES INLAND ON WEDNESDAY AND A DEEPENING LOW  
OVER THE GREAT LAKES PINCH THE RIDGE, BREAKING IT DOWN A BIT BUT  
MAINTAINING HIGH PRESSURE OVER THE REGION THROUGH THE END OF THE  
WEEK. GLOBAL MODELS CONTINUE TO FAVOR STORMS IN THE MOUNTAINS EACH  
AFTERNOON WEDNESDAY THROUGH FRIDAY, BUT LESSER CONFIDENCE IN  
WIDESPREAD STORMS OR SPILLOVER INTO THE URBAN REGIONS. THERE IS  
SUBSTANTIAL DISAGREEMENT ON THE LONG-TERM PATTERN FOR THE END OF THE  
WEEK AND INTO THE WEEKEND, WITH THE PLACEMENT OF THE RIDGE LIKELY TO  
DETERMINE TEMPERATURES AND MOISTURE SURGES/THUNDERSTORM CHANCES  
ACROSS THE DESERTS AND MOUNTAINS INTO THE WEEKEND. FOR NOW,  
TEMPERATURES LOOK TO COOL A BIT FROM THEIR PEAK ON MONDAY/TUESDAY  
WITH BOTH MOISTURE AND MID-LEVEL CLOUD COVER LIMITING AFTERNOON  
HEATING. HAVE MAINTAINED AT LEAST SLIGHT CHANCES FOR THUNDERSTORMS  
EACH AFTERNOON IN THE MOUNTAINS INTO THE WEEKEND.  
 
 
   
AVIATION  
 
302000Z...VFR THROUGH THIS EVENING REGION-WIDE. SCT-BKN LOW CLOUDS  
BASED 600-1000FT MSL START TO DEVELOP ALONG THE SD COUNTY COAST  
AFTER 08Z SUNDAY AND PUSH UP TO 5 MILES INLAND AFTER 12Z. 30-40%  
CHANCE BKN CIGS ALONG THE ORANGE COUNTY COASTLINE. LOW CLOUDS THAT  
MANAGE TO DEVELOP WILL RETREAT BACK TO THE COAST BY 16-17Z SUNDAY.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH WEDNESDAY.  
 
 
   
BEACHES  
 
A LONG-PERIOD (15-16 SEC) SOUTHERLY SWELL (180-200 DEGREES) WILL  
BRING ELEVATED SURF THROUGH TUESDAY, GRADUALLY SUBSIDING  
THEREAFTER. SURF OF 3-6 FEET WITH OCCASIONAL SETS TO 7 FEET FOR  
SOUTH-FACING BEACHES. HIGH RIP CURRENT RISK FOR ALL BEACHES. BEACH  
HAZARD STATEMENT IN EFFECT THROUGH LATE MONDAY.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR ORANGE COUNTY  
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.  
 
HEAT ADVISORY FROM 10 AM MONDAY TO 6 PM PDT TUESDAY FOR ORANGE  
COUNTY INLAND AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY  
VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY VALLEYS-SANTA  
ANA MOUNTAINS AND FOOTHILLS.  
 
PZ...NONE.  
 
 
 
 
 
PUBLIC...ZUBER  
AVIATION/MARINE/BEACHES...KW  
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