960  
FXUS66 KSGX 110413  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
913 PM PDT SUN MAY 10 2026  
   
SYNOPSIS
 
 
ABOVE AVERAGE TEMPERATURES WILL PREVAIL THROUGH MUCH OF THE FORECAST  
PERIOD. THE WARMEST CONDITIONS ARE EXPECTED MONDAY, WITH A  
GRADUAL COOLING TO WITHIN A FEW DEGREES OF NORMAL TUESDAY THROUGH  
FRIDAY. NIGHT AND MORNING LOW CLOUDS AND FOG WILL BE PRESENT EACH  
DAY ALONG THE COAST AND INTO PORTIONS OF THE VALLEYS. A GRADUAL  
WARMING TREND IS POSSIBLE NEXT WEEKEND.  
 

 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
 
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
   
..NEW AVIATION DISCUSSION FOR 06Z TAF PACKAGE
 
 
WARMING WILL CONTINUE INTO MONDAY WITH AN ADDITIONAL 3 TO 7  
DEGREE INCREASE COMPARED TO TODAY. THIS WILL BRING HIGH  
TEMPERATURES 10 TO 20 DEGREES ABOVE AVERAGE FOR INLAND LOCATIONS  
MONDAY AND 5 TO 8 DEGREES ABOVE AVERAGE ALONG THE COAST. AREAS OF  
WIDESPREAD MODERATE HEATRISK ARE EXPECTED IN THE INLAND EMPIRE AND  
HIGH DESERT WITH MAJOR HEATRISK IN THE LOW DESERTS THROUGH  
MONDAY. MAKE SURE TO STAY HYDRATED AND SEEK SHADE WHEN POSSIBLE IF  
WORKING OUTDOORS.  
 
TEMPERATURES ON TUESDAY WILL COOL 5 TO 12 DEGREES COMPARED TO MONDAY  
AS THE RIDGE ALOFT WEAKENS AND IS PUSHED EAST BY A SHORTWAVE TROUGH  
PASSING FROM OUR SOUTHWEST. THE PASSING SHORTWAVE WILL STRENGTHEN  
ONSHORE FLOW FOR TUESDAY AND WEDNESDAY, INCREASING SOUTH TO  
SOUTHEAST WINDS IN THE DESERTS ON TUESDAY AND WESTERLY WINDS FROM  
THE MOUNTAIN SLOPES INTO THE DESERTS ON WEDNESDAY. THIS PASSING  
FEATURE IS NOT EXPECTED TO HAVE MOISTURE ASSOCIATED WITH IT SO DRY  
CONDITIONS WILL PREVAIL.  
 
FOR WEDNESDAY THROUGH FRIDAY, MOST ENSEMBLE CLUSTERS ARE SHOWING A  
WEAK TROUGHING PATTERN PREVAILING OVER THE US WEST COAST. THIS WILL  
MAINTAIN MARINE LAYER LOW CLOUDS AND FOG FOR THE COAST AND VALLEYS  
AND TAKE HIGH TEMPERATURES BACK TO WITHIN A FEW DEGREES OF NORMAL.  
FOR NEXT WEEKEND, THE MAJORITY OF ENSEMBLE CLUSTERS KEEP THE UPPER  
LEVEL PATTERN WEAKLY TROUGHY TO ZONAL, WITH ONLY 10 PERCENT OF  
SOLUTIONS SHOWING WEAK RIDGING DEVELOPING BY NEXT SUNDAY. THE  
FORECAST FOR NEXT WEEKEND FOLLOWS THE NBM WHICH INDICATES A GRADUAL  
WARM UP FOR SATURDAY AND SUNDAY. THERE REMAINS LOW CONFIDENCE IN  
JUST HOW WARM IT WILL GET WITH THE DETERMINISTIC NBM AGAIN  
REPRESENTING THE HIGHEST PERCENTILES OF MOST OTHER ENSEMBLE  
GUIDANCE.  
 

 
   
AVIATION
 
 
110600Z...COAST/VALLEYS...LOW CLOUDS ARE POISED TO MOVE UP TO 10-15  
MILES INLAND OVERNIGHT. THERE IS LOWER CONFIDENCE ON TIMING CLOUDS  
REMAIN OFFSHORE THIS EVENING. BASES NEAR 1000-1300FT MSL WILL MOVE  
ONTO THE COAST, SLOWLY FALLING THROUGH THE NIGHT CLOSER TO 700-900FT  
MSL BY 10-13Z. LOWER CONFIDENCE IN CLOUDS REACHING KONT (20%)  
COMPARED TO SUNDAY MORNING. VIS REDUCTIONS 4-6SM IN BR FOR HIGHER  
COASTAL TERRAIN, WITH LOCALLY 1-3SM FOR INTERIOR VALLEYS. BASES  
LIKELY LIFTING BACK ABOVE 1000FT MSL BY 14-15Z, WITH FULL SCATTERING  
BACK OFFSHORE BY 16-17Z. ANOTHER ROUND OF LOW CLOUDS EXPECTED AGAIN  
MONDAY EVENING WITH SIMILAR BASES.  
 
MOUNTAINS/DESERTS...SKC AND VFR THROUGH MONDAY.  
 

 
   
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...HEAT ADVISORY FROM 10 AM TO 8 PM PDT MONDAY FOR SAN BERNARDINO  
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE.  
 
EXTREME HEAT WARNING UNTIL 8 PM PDT MONDAY FOR COACHELLA VALLEY-  
SAN DIEGO COUNTY DESERTS-SAN GORGONIO PASS NEAR BANNING.  
 
PZ...NONE.  
 

 
 

 
 
PUBLIC...CO  
AVIATION/MARINE...ZUBER  
 
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