777  
FXUS66 KSGX 110339  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
839 PM PDT THU JUL 10 2025  
   
SYNOPSIS  
 
HOT INLAND AND COOL AT THE COAST FOR THE REST OF TODAY. FRIDAY  
WILL COOL A LITTLE, WITH MINOR DAY TO DAY CHANGES THROUGH THE  
MIDDLE OF NEXT WEEK. A DEEPENING MARINE LAYER WILL BRING MORE  
COASTAL CLOUDS EXTENDING FARTHER INLAND DURING THE NIGHTS AND  
MORNINGS.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
UPDATE: THE FORECAST LOOKS TO REMAIN ON TRACK WITH THE RIDGE  
BREAKING DOWN SLIGHTLY AS A TROUGH DEEPENS FROM THE NORTH WITH A  
GRADUAL COOLDOWN BEGINNING TOMORROW AND GOING INTO THE WEEKEND. THIS  
WILL HELP TO COOL DOWN TEMPERATURES AND ALSO HELP TO LIFT AND  
THICKEN THE MARINE LAYER A BIT, ESPECIALLY BY EARLY NEXT WEEK, WITH  
ONLY A SLIGHT UPTICK IN TEMPERATURES ON SUNDAY AS THE HIGH PRESSURE  
CENTER BECOMES SITUATED OVER THE SOCAL BIGHT. 500 MB HEIGHTS ARE NOT  
GOING TO DEVIATE TOO MUCH EARLY NEXT WEEK, SO HIGH TEMPERATURES  
SHOULD REMAIN NEARLY CONSTANT FROM MONDAY THROUGH THURSDAY OF NEXT  
WEEK. THERE IS SOME INDICATION THAT MONSOONAL MOISTURE COULD MAKE  
ITS WAY OVER THE REGION ON THURSDAY OF NEXT WEEK AS MID-LEVEL  
FLOW BECOMES MORE SOUTHEASTERLY AND PROVIDES A VERY SLIGHT CHANCE  
OF THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS DURING THE  
AFTERNOON HOURS. OTHER THAN THAT, CONDITIONS WILL REMAIN DRY  
ELSEWHERE THROUGHOUT THE NEXT WEEK.  
 
(PREVIOUS DISCUSSION SUBMITTED AT 144 PM):  
 
TEMPERATURES WERE RUNNING VERY SIMILAR TO THOSE YESTERDAY AS OF  
MIDDAY, SOME A LITTLE HIGHER AND OTHERS A LITTLE LOWER. DESERTS  
ARE A LITTLE COOLER, WHILE MANY INLAND VALLEYS ARE A LITTLE  
WARMER. AREAS OF LOW CLOUDS ARE STICKING TO THE BEACHES IN SAN  
DIEGO COUNTY. TEMPERATURES TODAY SHOW A GREAT CONTRAST FROM THE  
TEMPERATE COAST TO THE SCORCHING DESERT. THE MIDDAY TEMP WAS 67 AT  
OCEANSIDE HARBOR AND 114 IN OCOTILLO WELLS. WHILE IT DOESN'T  
APPEAR DESERT TEMPS WILL REACH THOSE RECORD LEVELS OF YESTERDAY,  
EXTREME HEAT WARNINGS ARE WARRANTED AND STILL IN PLACE FOR THE  
LOWER DESERTS THROUGH SUNSET. IN THE VALLEYS, HIGHS WILL BE IN THE  
90S TO ABOUT 106 AND A HEAT ADVISORY IS OUT TODAY, PARTICULARLY  
FOR THE MORE INLAND VALLEYS WHERE A FEW TEMPS IN SPOTS ALREADY  
EXCEED 100. THESE INLAND HIGHS REPRESENT 6 TO 12 DEGREES ABOVE  
NORMAL TODAY. A HEAT ADVISORY REMAINS IN EFFECT THROUGH SUNSET. A  
TEMPORARY BUT STRONG RIDGE OVERHEAD HAS BROUGHT OUR REGION THE  
KIND OF SUBSIDENCE AND COMPRESSIONAL HEATING NEEDED FOR THIS HEAT  
EPISODE. THIS SHOULD BE THE FINAL DAY OF EXTREME HEAT. THIS HIGH  
WILL WEAKEN SLIGHTLY FRIDAY, AND SOME ADDITIONAL GULF MOISTURE  
CREEPS INTO THE LOWER DESERTS, ALLOWING FOR A DROP OF SEVERAL  
DEGREES, BUT STILL UP TO 8 DEGREES ABOVE NORMAL IN THE LOW DESERT  
FOR MID JULY. VALLEYS WILL TREND CLOSE TO NORMAL FOR THE WEEKEND.  
THE MARINE LAYER WILL GET A BOOST BY A COASTAL EDDY TONIGHT AND  
FRIDAY TO REBUILD AND EXTEND LOW CLOUDS AND FOG INTO WESTERN  
VALLEYS AND FOR A LONGER TIME EACH NIGHT AND MORNING. FOR NEXT  
WEEK, MINOR VARIATIONS IN THE UPPER HIGH WILL MAINTAIN THIS RATHER  
SEASONAL WEATHER, EXCEPT SLIGHTLY HOTTER THAN AVERAGE IN THE  
DESERTS. THERE ARE HINTS OF MONSOON MOISTURE INCREASING NEXT  
WEDNESDAY THROUGH FRIDAY FOR AN EXTREMELY SLIGHT (BUT NONZERO)  
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHERN INTERIOR.  
WE'LL NEED MORE CONSISTENCY AND CONSENSUS IN ENSEMBLE SOLUTIONS  
THAT FAR OUT TO ADD PRECIP TO THE FORECAST.  
 
 
   
AVIATION  
 
110330Z....COAST/VALLEYS...LOW CLOUDS FILL BACK IN AND PUSH ASHORE  
TONIGHT AFTER 04Z, BASED 1100-1500 FT MSL, MOVING INLAND TO ABOUT 15  
MILES INLAND. 55% CHANCE FOR CIGS AT KSNA BY 10Z TONIGHT. SCATTERING  
BACK TO THE BEACHES BY 16-18Z, BUT PATCHY CLOUDS WILL LINGER ALONG  
THE BEACHES THROUGH THE AFTERNOON. CLOUDS WITH SIMILAR BASES MOVE  
INLAND AGAIN AFTER 02Z SAT.  
 
MOUNTAINS/DESERTS...VFR CONDITIONS AND UNRESTRICTED VIS THROUGH  
FRIDAY.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS EXPECTED THROUGH MONDAY.  
 
 
   
SKYWARN  
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
UPDATE...STEWEY  
PUBLIC...MM  
AVIATION/MARINE...CSP  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab CA Page
Main Text Page