286  
FXUS66 KSGX 190943  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
243 AM PDT THU MAR 19 2026  
   
SYNOPSIS
 
 
RECORD HEAT FOR MARCH WILL CONTINUE FOR INLAND AREAS INTO THE  
WEEKEND WHILE THE MARINE LAYER WITH PATCHY NIGHT AND MORNING LOW  
CLOUDS AND LOCALLY DENSE FOG KEEPS THE BEACHES COOLER. COOLING  
WILL BEGIN TO SPREAD INLAND OVER THE WEEKEND INTO EARLY NEXT  
WEEK, BUT WITH HIGH TEMPERATURES FOR SOME INLAND AREAS REMAINING  
MORE THAN 20 DEGREES ABOVE AVERAGE WITH DAILY RATHER THAN MONTHLY  
RECORDS FOR HEAT CONTINUING TO FALL.  
 

 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
 
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
   
SHORT TERM (TODAY THROUGH SATURDAY)
 
 
HIGH PRESSURE ALOFT CONTINUES TO STRENGTHEN OVER SOUTHERN  
CALIFORNIA WITH THE HEAT FOR INLAND AREAS OF SOUTHWESTERN  
CALIFORNIA EXPECTED TO PEAK ON FRIDAY. WEAKENING OF HIGH PRESSURE  
ALOFT AND ONSHORE FLOW WILL BEGIN TO SPREAD COOLING INLAND OVER  
THE WEEKEND INTO EARLY NEXT WEEK.  
 
THERE IS A WEAK COASTAL EDDY EARLY THIS MORNING WITH LOW CLOUDS  
AND FOG OVER THE INNER COASTAL WATERS EXTENDING LOCALLY INLAND  
ALONG THE COAST WITH FOG LOCALLY DENSE. A LITTLE LESS COVERAGE  
OVER LAND AREAS IS EXPECTED FOR TONIGHT INTO FRIDAY MORNING WITH  
INCREASING COVERAGE OF NIGHT AND MORNING LOW CLOUDS AND FOG FOR  
COASTAL AREAS DURING THE WEEKEND.  
 
HIGH TEMPERATURES ON FRIDAY ARE EXPECTED TO BE AROUND 30 DEGREES  
ABOVE AVERAGE FOR THE INLAND VALLEYS AND LOWER ELEVATIONS OF THE  
MOUNTAINS WITH HIGH TEMPERATURES RANGING FROM AROUND 80 AT THE  
BEACHES TO THE UPPER 90S TO 104 FOR THE INLAND EMPIRE WITH 105 TO  
110 FOR THE LOWER DESERTS. COOLING OF HIGH TEMPERATURES ON  
SATURDAY OF AROUND 4 TO 8 DEGREES IS EXPECTED FOR ALL BUT THE  
LOWER DESERTS.  
 

 
   
LONG TERM (SUNDAY THROUGH WEDNESDAY)
 
 
HIGH TEMPERATURES ON SUNDAY WILL COOL A FEW DEGREES FOR MOST  
AREAS WITH HIGH TEMPERATURES STILL AROUND 20 DEGREES ABOVE AVERAGE  
FOR THE MOUNTAINS, DESERTS, AND INLAND VALLEYS. HIGH TEMPERATURES  
ON SUNDAY ARE EXPECTED TO RANGE FROM THE MID TO UPPER 70S NEAR THE  
COAST TO THE UPPER 80S TO MID 90S FOR THE INLAND EMPIRE WITH 100  
TO 105 FOR THE LOWER DESERTS. HIGH TEMPERATURES FOR EARLY NEXT  
WEEK WILL FLUCTUATE WITHIN A FEW DEGREES OF SUNDAY HIGH  
TEMPERATURES EACH DAY.  
 
EXCEPT NEAR THE COAST, WIDESPREAD DAILY RECORDS FOR HEAT WILL  
CONTINUE TO BE TIED OR BROKEN, BUT WITH FEW OR NO NEW MONTHLY  
RECORDS FOR MARCH AFTER FRIDAY OR SATURDAY.  
 

 
   
AVIATION
 
 
190900Z...LOW CLOUDS AND FOG VCNTY KSAN WITH CIGS 200-300 FT MSL AND  
VIS 0.25-1 MILE LIKELY TO CONTINUE THROUGH 15Z. ELSEWHERE, MOSTLY  
CLEAR SKIES AND UNRESTRICTED VIS THROUGH THIS EVENING. PATCHY LOW  
CLOUDS AND FOG RETURNING TO THE IMMEDIATE COAST AFTER 03Z FRIDAY.  
 

 
   
MARINE
 
 
PATCHES OF FOG WITH VISIBILITY 1 NAUTICAL MILE WITHIN 20 MILES OF  
THE COAST THIS MORNING. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS  
ARE EXPECTED THROUGH MONDAY.  
 

 
   
CLIMATE
 
 
PRIOR TO 2026, THE HIGHEST 500 MB HEIGHT FOR SAN DIEGO FOR MARCH  
HAD BEEN 590 DM. IN THE PRIOR THREE SOUNDINGS FOR NKX, NEW RECORDS  
FOR THE MONTH HAVE BEEN SET AT 592 DM, 594 DM, AND NOW 595 DM FOR  
LATE WEDNESDAY AFTERNOON. PRIOR TO THIS YEAR, THE EARLIEST A 500  
MB HEIGHT OF 595 DM HAD OCCURRED AT SAN DIEGO HAD BEEN JUNE 4TH.  
THE 500 MB HEIGHT FOR THE NEXT SOUNDING EARLY THIS MORNING WILL  
LIKELY BE HIGHER THAN THAT. THE EARLIEST A HEIGHT OF 596 DM HAS  
OCCURRED IS JUNE 5TH AND THE EARLIEST A 500 HEIGHT OF 597 DM HAS  
OCCURRED IS JUNE 20TH.  
 
THE HIGH TEMPERATURE OF 108 ON WEDNESDAY AT NORTH SHORE,  
CA, TO THE EAST OF THE SALTON SEA, APPEARS TO HAVE TIED TO THE  
EXISTING HIGHEST TEMPERATURE EVER RECORDED IN MARCH IN THE UNITED  
STATES. THERE ARE LOCATIONS IN THE COACHELLA VALLEY AND SAN DIEGO  
COUNTY DESERTS THAT COULD EQUAL OR EXCEED THAT TEMPERATURE FOR  
TODAY AND ESPECIALLY ON FRIDAY.  
 

 
   
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 FRIDAY FOR ORANGE COUNTY COASTAL  
AREAS-ORANGE COUNTY INLAND AREAS-RIVERSIDE COUNTY MOUNTAINS-  
SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO AND  
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY  
COASTAL AREAS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY  
VALLEYS-SANTA ANA MOUNTAINS AND FOOTHILLS.  
 
EXTREME HEAT WARNING UNTIL 8 PM PDT SATURDAY FOR COACHELLA  
VALLEY-SAN DIEGO COUNTY DESERTS-SAN GORGONIO PASS NEAR  
BANNING.  
 
PZ...NONE.  
 

 
 

 
 
PUBLIC/CLIMATE...17  
AVIATION/MARINE...PG  
 
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