853  
FXUS66 KSGX 291836  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
1136 AM PDT SAT AUG 29 2026  
   
SYNOPSIS  
 
GRADUAL COOLING TREND THROUGH THE MIDDLE OF THE UPCOMING WEEK. FOR  
TUESDAY AND WEDNESDAY, INCREASED HIGH CLOUD COVER IS LIKELY ALONG  
WITH A 15 TO 25 PERCENT CHANCE OF LIGHT PRECIPITATION AS MOISTURE  
FROM TROPICAL CYCLONE KARINA POTENTIALLY GETS PULLED NORTHWARD. THIS  
TROPICAL SYSTEM IS FORECAST TO REMAIN WELL TO OUR SOUTH. GRADUAL  
WARMING FOR THE LATTER HALF OF NEXT WEEK. NIGHT AND MORNING LOW  
CLOUDS WILL BE MORE WIDESPREAD FOR THE UPCOMING WEEK, REACHING INTO  
THE WESTERN VALLEYS AT TIMES.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
WHILE HIGH TEMPERATURES TODAY WILL REMAIN 3 TO 7, LOCALLY UP TO 12  
DEGREES ABOVE AVERAGE THEY'RE FORECAST TO BE 3 TO 5 DEGREES COOLER  
THAN YESTERDAY. THAT COOLING TREND WILL CONTINUE THROUGH TUESDAY  
OR WEDNESDAY FOR MOST LOCATIONS. BY WEDNESDAY, HIGH TEMPERATURES  
ARE EXPECTED TO BE 3 TO 7 DEGREES BELOW AVERAGE FOR THIS TIME OF  
YEAR. ADDITIONALLY, MARINE LAYER LOW CLOUDS AND AREAS OF FOG WILL  
BECOME MORE PREVALENT ALONG THE COAST AND IN THE WESTERN VALLEYS  
AT TIMES.  
 
MOISTURE FROM TROPICAL CYCLONE KARINA MAY BE PULLED INTO SOUTHERN  
CALIFORNIA BY MID-WEEK. THERE IS HIGH CONFIDENCE THIS WILL  
INCREASE HIGH CLOUD COVERAGE ACROSS THE AREA, WITH LESSER  
CONFIDENCE IN CHANCES OF LIGHT RAIN. CURRENT FORECAST HAS PULLED  
RAINFALL CHANCES BACK FOR MUCH OF WEDNESDAY, LEAVING THE HIGHEST  
CHANCES ON TUESDAY AT 15-25 PERCENT. MODEL GUIDANCE STILL IS YET  
TO ALIGN ON THE AMOUNT OF MOISTURE THAT MOVES INTO OUR AREA. THE  
EC CONTINUES TO TREND DRIER THAN THE GFS/CANADIAN. HOW THE  
TROPICAL CYCLONE TRACKS WILL ULTIMATELY BE THE BIGGEST INFLUENCE  
IN MOISTURE INFLUX, WITH A MORE WESTERLY TRACK BEING DRIER FOR US  
AND A MORE EASTERLY TRACK BEING WETTER. CURRENT FORECAST CLOSELY  
FOLLOWS THE NBM.  
 
THURSDAY INTO NEXT WEEKEND, THE UPPER LEVEL HIGH BEGINS TO SHIFT  
BACK WESTWARD, BRINGING WARMING AND THE POTENTIAL RETURN OF MONSOON  
MOISTURE. HIGH TEMPERATURES RETURN TO NEAR AVERAGE BY FRIDAY.  
 
 
   
AVIATION  
 
291800Z...COAST...LOW CLOUDS BASED AROUND 600FT MSL REMAIN SITUATED  
ALONG THE BEACHES AND OFFSHORE OF SOUTH-CENTRAL SAN DIEGO COUNTY  
THIS MORNING, AND WILL LIKELY CONTINUE INTO THE EARLY AFTERNOON. LOW  
CLOUDS ARE EXPECTED TO REDEVELOP AFTER 06Z SUNDAY, LIKELY BECOMING  
MORE WIDESPREAD OVERNIGHT COMPARED TO WHAT HAS BEEN SEEN IN RECENT  
DAYS. 80% CHANCE OF CIGS ACROSS COASTAL SAN DIEGO COUNTY (KSAN AND  
KCRQ) BY 09-11Z, WITH A ~30% CHANCE OF CIGS REACHING COASTAL ORANGE  
COUNTY (KSNA) FOR 12-16Z. BASES ARE EXPECTED TO BE AROUND 600-1000  
FT MSL. ANY CLOUDS THAT MOVE INLAND WILL SCATTER BACK TO THE  
BEACHES/OFFSHORE BY 16-17Z.  
 
ELSEWHERE...WIDESPREAD GUSTS TO 15-25 KTS IN THE MOUNTAINS AND  
DESERTS THIS AFTERNOON/EVENING, LOCALLY UP TO 35 KTS WITHIN MOUNTAIN  
PASSES. GUSTS WEAKEN AFTER 03Z SUNDAY.  
 
 
   
MARINE  
 
GUSTS AROUND 20 KNOTS EXPECTED EACH AFTERNOON THROUGH MONDAY IN THE  
VICINITY OF SAN CLEMENTE ISLAND. OTHERWISE, NO HAZARDOUS MARINE  
CONDITIONS ARE EXPECTED THROUGH THURSDAY.  
 
 
   
BEACHES  
 
A 3-FOOT SWELL FROM THE SOUTH-SOUTHWEST (200 DEGREES) AT 15-17  
SECONDS WILL PERSIST INTO SUNDAY. THIS WILL BRING LOCALIZED ELEVATED  
SURF OF 3-5 FEET WITH SETS TO 6 FEET, ALONG WITH A HIGH RIP CURRENT  
RISK TO SOUTHWEST-FACING BEACHES, MOSTLY IN NORTH SAN DIEGO COUNTY  
AND ORANGE COUNTY. A NEW PULSE OF SOUTHERLY SWELL (180-190 DEGREES)  
FROM TROPICAL STORM KARINA WILL KEEP SURF ELEVATED AT 3-6 FEET FOR  
MONDAY THROUGH WEDNESDAY.  
 
 
   
SKYWARN  
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...HEAT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR ORANGE COUNTY  
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.  
 
EXTREME HEAT WARNING UNTIL 8 PM PDT THIS EVENING FOR COACHELLA  
VALLEY-ORANGE COUNTY INLAND AREAS-SAN BERNARDINO AND  
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY  
DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY VALLEYS-  
SAN GORGONIO PASS NEAR BANNING-SANTA ANA MOUNTAINS AND  
FOOTHILLS.  
 
PZ...NONE.  
 
 
 
 
 
PUBLIC...CO  
AVIATION/MARINE/BEACHES...MUNYAN  
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