361  
FXUS66 KSGX 040356  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
856 PM PDT THU JUL 3 2025  
   
SYNOPSIS
 
 
MINOR WARMING THROUGH THE HOLIDAY WEEKEND WITH HIGHS NEAR NORMAL  
AND NIGHT AND MORNING LOW CLOUDS CONTINUING ALONG THE COASTAL  
AREAS AND WESTERN VALLEYS. A RIDGE OF HIGH PRESSURE WILL  
STRENGTHEN OVER THE REGION, LEADING TO BUILDING CONFIDENCE IN A  
HEAT WAVE ACROSS THE AREA AND THE POTENTIAL FIRST PUSH OF MONSOON  
MOISTURE BY THE MIDDLE OF NEXT WEEK.  
 

 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
 
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
EVENING UPDATE...  
LOW CLOUDS HAVE BEGUN TO SPREAD BACK INTO THE COASTAL AREAS THIS  
EVENING, BUT ELSEWHERE SKIES REMAIN CLEAR ASIDE FROM HIGH LEVEL  
SMOKE FROM A WILDFIRE IN SAN LUIS OBISPO COUNTY. NO CHANGES TO  
THE FORECAST THIS EVENING. TWO MAIN CAVEATS IN THE FORECAST REMAIN  
FOR THE MIDDLE OF NEXT WEEK. ONE: IF LOW-LEVEL MOISTURE MAKES IT  
INTO THE LOWER DESERTS DURING THE PEAK OF THE HEAT WAVE, HIGH  
TEMPERATURES COULD END UP BEING SEVERAL DEGREES LOWER THAN WHAT IS  
CURRENTLY FORECAST FOR THOSE AREAS. TWO: WHILE THERE IS GROWING  
CONFIDENCE THAT MONSOON MOISTURE WILL SPREAD INTO THE AREA,  
WHETHER OR NOT WE GET ANY PRECIPITATION ON IT WILL DEPEND ON THE  
POSITION OF THE UPPER LEVEL RIDGE AXIS AND ASSOCIATED SUBSIDENCE  
INVERSION ACTING AS A CAP.  
 
PREVIOUS DISCUSSION...  
A WEAK TROUGHING PATTERN IS EXPECTED TO LINGER ACROSS  
THE THE REGION THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS ACROSS  
THE NORTHERN MEXICO. AS THE HIGH BUILDS AND PRESSURE HEIGHTS  
INCREASE A LOT, SUBTLE WARMING BY A 3-5 DEGREES WILL OCCUR BY  
FRIDAY, LASTING THROUGH THE HOLIDAY WEEKEND. THIS WILL BRING  
TEMPERATURES CLOSER TO NORMAL FOR EARLY JULY. LOW CLOUDS WILL  
CONTINUE TO PUSH ASHORE EACH NIGHT INTO THE MORNING FOR COASTAL  
AND WESTERN VALLEY REGIONS.  
 
CONFIDENCE CONTINUES TO INCREASE ON A BUILDING HEATWAVE BY THE  
MIDDLE OF NEXT WEEK AS HIGH PRESSURE OVER MEXICO, MOVES OVER OUR  
AREA. EXACT PLACEMENT OF THIS SYSTEM IS BECOMING BETTER ALIGNED,  
WHERE IT INDICATES THE SYSTEM PEAKING OVER MUCH OF SOUTHERN  
CALIFORNIA. THIS LEADS TO INCREASED CONFIDENCE OF STORM CHANCES TO  
BE LIMITED BELOW 10 PERCENT, AS A SLIGHT UPTICK IN MONSOONAL  
MOISTURE WORKS ITS WAY INTO SOCAL BY TUESDAY AND WEDNESDAY. THIS  
WILL LEAD TO A BIT MORE HUMIDITY WITH THE HOT WEATHER, ESPECIALLY  
FOR MOUNTAINS AND DESERTS. 850MB TEMPERATURES PEAK ON WEDNESDAY  
AND THURSDAY AS A NEAR ~ 600 DM HIGH MOVES OVER THE REGION. THIS  
WILL TRIGGER HIGHS NEAR 10 DEGREES ABOVE NORMAL BY THE MIDDLE OF  
THE WEEK WITH HIGH CONFIDENCE IN TEMPERATURES RISING OVER 100  
DEGREES ACROSS THE HIGH DESERT AND INLAND EMPIRE. WE WILL ALSO BE  
KEEPING AN EYE ON MOUNTAINOUS AREAS, WHERE NBM SHOWS MODERATE TO  
HIGH CHANCES OF PLACES LIKE JULIAN AND ANZA SEEING HIGHS REACH AT  
LEAST 95 DEGREES. 80S AND 90S CAN BE EXPECTED FOR OTHER MOUNTAIN  
AREAS AND VALLEYS CLOSER TO THE COAST. THOSE WITH HEAT  
SENSITIVITIES OR WITHOUT PROPER COOLING METHODS SHOULD CONTINUE TO  
MONITOR THE FORECAST. ENSEMBLE MODELS SHOW A SUBTLE DECREASE IN  
THE HIGH'S INTENSITY BY THE END OF THE WEEK, WHICH WOULD LEAD TO  
CONTINUED HOT TEMPERATURES BUT NOT AS INTENSE.  
 

 
   
AVIATION
 
 
040315Z....COAST/VALLEYS...LOW CLOUDS BASED 1000-1500 FT MSL WILL  
PUSH INLAND INTO THE WESTERN VALLEYS AND FAR WESTERN AND SOUTHERN IE  
OVERNIGHT. THERE IS A 40% CHANCE FOR CLOUDS TO REACH AS FAR AS KONT  
13-15Z. LOCALIZED VIS REDUCTIONS DOWN TO 3-5SM FOR VALLEY HIGHER  
TERRAIN. CLOUDS TO CLEAR TO THE BEACHES BY 16-17Z FRI, WITH  
LINGERING CLOUDS AT SOME BEACHES INTO THE AFTERNOON. LOW CLOUDS WITH  
SLIGHTLY LOWER BASES 800-1200 FT MSL WILL REFORM AND PUSH BACK  
ASHORE AFTER 03Z SAT.  
 
MOUNTAINS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH  
FRIDAY.  
 

 
   
MARINE
 
 
NO HAZARDOUS MARINE WEATHER CONDITIONS ARE EXPECTED THROUGH TUESDAY.  
 

 
   
BEACHES
 
 
BUILDING SOUTHERLY SWELL (190 DEGREES) OF 3 FEET AT 15-17 SECONDS  
WILL GENERATE ELEVATED SURF OF 3-5 FT WITH SETS TO 6 FT ALONG  
SOUTHERLY FACING BEACHES THROUGH SATURDAY. IN ADDITION, STRONG RIP  
AND LONGSHORE CURRENTS EXPECTED AT ALL BEACHES FRIDAY AND SATURDAY.  
A BEACH HAZARDS STATEMENT IS IN EFFECT AND CONTAINS MORE  
INFORMATION. SWELL AND SURF WILL BEGIN TO LOWER ON SUNDAY.  
 

 
   
SKYWARN
 
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 

 
   
SGX WATCHES/WARNINGS/ADVISORIES
 
 
CA...BEACH HAZARDS STATEMENT THROUGH SATURDAY EVENING FOR ORANGE  
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.  
 
PZ...NONE.  
 

 
 

 
 
PUBLIC...SS/APR  
AVIATION/MARINE/BEACHES...CSP  
 
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