574  
FXUS66 KSGX 061808  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
1108 AM PDT THU AUG 6 2026  
   
SYNOPSIS
 
 
THE HEATRISK WILL CONTINUE TO SLOWLY INCREASE THROUGH SATURDAY  
WITH WIDESPREAD MAJOR HEATRISK FOR THE DESERTS AND WIDESPREAD  
MODERATE HEATRISK FOR INLAND EMPIRE AND FOR THE MOUNTAINS BELOW  
6500 FEET. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON SHOWERS AND  
THUNDERSTORMS FOR THE MOUNTAINS THROUGH NEXT TUESDAY WITH THE  
RELATIVELY GREATER CHANCES FOR THIS AFTERNOON AND AGAIN FOR SUNDAY  
THROUGH TUESDAY. GRADUAL COOLING AND DRYING WILL THEN FOLLOW FOR  
THE REST OF NEXT WEEK.  
 

 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
 
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
   
..UPDATED AVIATION DISCUSSION
 
 
   
SHORT TERM (TODAY THROUGH SATURDAY)
 
 
ENSEMBLE OUTPUT SHOWS PRECIPITABLE WATER VALUES PEAKING THIS  
AFTERNOON, THEN DECLINING INTO SATURDAY AFTERNOON. THE PEAK HOURLY REFS  
90TH PERCENTILE RAINFALL IS AROUND 0.75 INCH FOR THIS AFTERNOON  
AND AROUND 0.25 INCH FOR FRIDAY AFTERNOON. THERE IS A SLIGHT  
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS FOR THIS  
AFTERNOON WITH SLOWLY DECREASING CHANCES FOR FRIDAY AFTERNOON AND  
SATURDAY AFTERNOON.  
 
THE HEATRISK WILL CONTINUE TO SLOWLY INCREASE THROUGH SATURDAY  
WITH WIDESPREAD MAJOR HEATRISK FOR THE DESERTS AND WIDESPREAD  
MODERATE HEATRISK FOR INLAND EMPIRE AND FOR THE MOUNTAINS BELOW  
6500 FEET. HIGH TEMPERATURES ON SATURDAY WILL BE A FEW DEGREES  
ABOVE AVERAGE NEAR THE COAST TO 5 TO 10 DEGREES ABOVE AVERAGE FOR  
THE DESERTS. HIGH TEMPERATURES ON SATURDAY WILL RANGE FROM THE MID  
70S TO LOWER 80S NEAR THE COAST TO THE MID 90S TO 105 FOR THE  
INLAND EMPIRE WITH 110 TO 114 FOR THE LOWER DESERTS.  
 
NIGHT AND MORNING WILL CONTINUE TO SPREAD INTO COASTAL AREAS, BUT  
WITH SOME OCCASIONAL DISRUPTIONS IN COVERAGE FROM MID LEVEL  
MONSOONAL MOISTURE AND CLOUDS.  
 

 
   
LONG TERM (SUNDAY THROUGH WEDNESDAY)
 
 
THE EXTREME HEAT WARNING FOR THE DESERTS AND HEAT ADVISORY FOR THE  
MOUNTAINS AND INLAND EMPIRE HAS BEEN EXTENDED THROUGH SUNDAY WITH  
ONLY A SLIGHT DECLINE IN HEATRISK ON SUNDAY. GREATER DECLINES ARE  
EXPECTED FOR MONDAY AND TUESDAY WITH MODERATE HEATRISK FOR NEXT  
TUESDAY CONFINED MOSTLY TO THE DESERTS.  
 
ENSEMBLE OUTPUT SHOWS ANOTHER PEAK IN PRECIPITABLE WATER VALUES  
FOR SUNDAY AFTERNOON, SIMILAR TO THE PEAK FOR THIS AFTERNOON, THEN  
A GRADUAL SLOW DECLINE THROUGH NEXT WEEK. A SLIGHT CHANCE FOR  
AFTERNOON SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS WILL  
CONTINUE FOR SUNDAY THROUGH TUESDAY WITH GRADUAL COOLING AND  
DRYING FOR THE REST OF NEXT WEEK. FOR THURSDAY OF NEXT WEEK, HIGH  
TEMPERATURES FOR THE DESERTS AND NEAR THE COAST WILL BE AROUND  
AVERAGE AND COULD BE AS MUCH AS 4 TO 8 DEGREES BELOW AVERAGE FOR  
THE INLAND VALLEYS. FOR THURSDAY OF NEXT WEEK, HIGH TEMPERATURES  
COULD RANGE FROM THE 70S NEAR THE COAST TO THE MID 80S TO MID 90S  
FOR THE INLAND EMPIRE WITH 106 TO 110 FOR THE LOWER DESERTS.  
 

 
   
AVIATION
 
 
061800Z....COASTS/VALLEYS...SATELLITE SHOWS LOW CLOUDS HAVE CLEARED  
THE COAST WITH FEW-SCT HIGH CLOUDS AOA 20,000FT MSL MOVING IN FROM  
THE SOUTH. VFR THROUGH THE REMAINDER OF THE AFTERNOON. PATCHY LOW  
CLOUDS BASED 800-1200FT MSL TONIGHT DEVELOP AND MOVE INLAND LIKELY  
AFTER 03Z FRI, SPREADING NORTH INTO ORANGE COUNTY AFTER 07Z. 50%  
CHANCE OF A BRIEF CIG AT KCRQ. VIS POTENTIALLY DOWN TO 3-5SM FOR  
VALLEYS AND COASTAL TERRAIN. CLEARING OUT ON FRIDAY SHOULD OCCUR AT  
A SIMILAR PACE TO THIS MORNING, AROUND 16-18Z.  
   
MOUNTAINS/DESERTS
 
ISO SHRA/TSRA (15% CHANCE) MAY DEVELOP ALONG  
MTN RIDGES 20-23Z. OTHERWISE, FEW-SCT CU AOA 20,000FT MSL WITH  
UNRESTRICTED VIS INTO FRIDAY.  
 

 
   
MARINE
 
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.  
 

 
   
SGX WATCHES/WARNINGS/ADVISORIES
 
 
CA...HEAT ADVISORY UNTIL 8 PM PDT SUNDAY FOR RIVERSIDE COUNTY  
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO  
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO  
COUNTY MOUNTAINS.  
 
EXTREME HEAT WARNING UNTIL 8 PM PDT SUNDAY FOR APPLE AND LUCERNE  
VALLEYS-COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS-SAN  
GORGONIO PASS NEAR BANNING.  
 
PZ...NONE.  
 

 
 

 
 
PUBLIC...MARTIN  
AVIATION/MARINE...ZUBER  
 
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