629  
FXUS66 KSGX 180539  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
1039 PM PDT FRI JUL 17 2026  
   
SYNOPSIS  
 
TEMPERATURES COOLING FOR INLAND AREAS TODAY WILL BE SIMILAR INTO  
MUCH OF NEXT WEEK. CHANCES OF THUNDERSTORMS ARE ELEVATED ONCE  
AGAIN ACROSS THE MOUNTAINS THIS AFTERNOON. STORM CHANCES BEGIN TO  
DECREASE WITH MINOR CHANCES EXPECTED FOR HIGHEST RIDGES IN THE SAN  
BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS EACH AFTERNOON INTO THE  
FIRST HALF OF NEXT WEEK. CONFIDENCE LOWERS FOR INCREASING CHANCES  
LATER IN THE WEEK. LOW CLOUDS WILL CONTINUE TO COVER COASTAL  
AREAS EACH NIGHT AND MORNING INTO THE NEXT WEEK AS WELL.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
   
..UPDATED AVIATION DISCUSSION  
 
   
..UPDATED BEACHES DISCUSSION  
 
PREVIOUS DISCUSSION...1245 PM PDT FRI JUL 17 2026...  
SATELLITE IMAGERY SHOES SHOWS MID-LEVEL CLOUDS OVER PARTS OF  
SOCAL AND FURTHER TO THE EAST, WITH DRYING TRENDS NOTICED OVER  
NORTHERN PORTIONS OF THE MOUNTAINS. CLEARING THIS MORNING WILL  
CREATE A BETTER ENVIRONMENT FOR THUNDERSTORM ACTIVITY AS WE HEAD  
INTO THE AFTERNOON. COMPARING YESTERDAY TO TODAY, THE ENVIRONMENT  
IS SEEMINGLY A BIT LESS PRIMED WITH LESS INSTABILITY, THOUGH PWATS  
ARE STILL NEAR 1.5", PLENTY MOIST ENOUGH. LATEST HI- RES MODEL  
GUIDANCE AGAIN FAVORS THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS  
TO RECEIVE THE GREATEST RAINFALL, LOCALLY NEAR 0.50"-1" PER HOUR  
RATES, FOR LATER THIS AFTERNOON. STORMS WILL BEGIN TO WEAKEN BY  
EARLY EVENING. OTHERWISE, TEMPERATURES TODAY WILL FEEL NOT AS HOT  
AS YESTERDAY. HIGH TEMPERATURES WILL BE CLOSER TO AVERAGE WITH  
HIGHS IN THE 90S ACROSS THE IE AND HIGH DESERT, AND 70S/80S FOR  
THE COAST, WESTERN VALLEYS AND MOUNTAINS. ELEVATED HUMIDITY WITH  
OVERNIGHT LOWS NEAR TO SLIGHTLY ABOVE AVERAGE WILL REMAIN THOUGH.  
 
MOISTURE AROUND AN AREA OF HIGH PRESSURE OVER THE INTERMOUNTAIN WEST  
DECREASES AND PUSHES FURTHER EAST BY THE WEEKEND. MOISTURE WILL  
STILL REMAIN IN PLACE, SO CHANCES DO REMAIN OVER THE HIGHER  
MOUNTAINS OF SBD/RIV COUNTIES ON SATURDAY. THE ATMOSPHERE LOOKS TO  
DRY OUT A BIT FURTHER BY SUNDAY THROUGH TUESDAY, BRINGING CHANCES  
NEAR 10-15% ALONG THE EASTERN PARTS OF THE SBD MTS. OTHER THAN THIS,  
THE OVERALL WEATHER PATTERN WILL REMAIN RELATIVELY UNCHANGED WITH  
TEMPERATURES NEAR AVERAGE WITH MOSTLY CLEAR CONDITIONS.  
 
THE FORECAST IN MONSOONAL MOISTURE BECOMES LESS CERTAIN BY THE  
LATTER HALF OF NEXT WEEK. MODELS STILL CONTINUE TO BE SPLIT ON THE  
PLACEMENT OF THE AREA OF HIGH PRESSURE, WHICH WILL DICTATE WHERE AND  
HOW MUCH MONSOONAL MOISTURE WE ARE ABLE TO RECEIVE. THIS WILL ALSO  
DICTATE IF WE STAY NEAR NORMAL OR WARM SLIGHTLY ABOVE NORMAL.  
 
 
   
AVIATION  
 
180530Z....COAST/VALLEYS...MID-LEVEL CLOUDS 15-20KFT MSL ARE  
CURRENTLY INHIBITING LOW CLOUDS FROM FORMING ALONG THE COAST, WHICH  
WILL LIKELY CONTINUE THROUGH 08-09Z. PATCHY LOW CLOUDS 900-1300 FT  
MSL WILL MOVE INTO COASTAL REGIONS AFTER, BECOMING MORE WIDESPREAD  
AS MID-LEVELS CONTINUE TO CLEAR TOWARDS AROUND 12Z. LOW CLOUDS CLEAR  
15-17Z, THEN REFORM AT SIMILAR BASES AND MOVE INTO COASTAL REGIONS  
AFTER 05Z SUN.  
   
MOUNTAINS/DESERTS  
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH  
SCT MID-LEVEL CLOUDS AOA 15,000FT MSL GRADUALLY CLEARING OVERNIGHT.  
SCT CU BASED 10-12 KFT MSL WILL DEVELOP OVER THE RIVERSIDE AND SAN  
BERNARDINO MTNS AFTER 18Z AND ISO-SCT SHRA/TSRA , MOST LIKELY AFTER  
20Z, THROUGH 01Z SUNDAY. ANY STORMS THAT DEVELOP MAY PRODUCE  
LIGHTNING, GUSTY WINDS, AND VIS REDUCTIONS.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH WEDNESDAY.  
 
 
   
BEACHES  
 
HIGH AMPLITUDE SOUTHERLY SWELL (4-5 FT WITH A PERIOD OF 12-13  
SECONDS) WILL BUILD SUNDAY, BRINGING ELEVATED TO HIGH SURF AND  
STRONG RIP AND LONGSHORE CURRENTS FOR SUNDAY THROUGH AT LEAST  
TUESDAY. HIGHEST SURF, UP TO 7-9 FT, WILL BE ALONG SOUTH AND  
SOUTHWEST-FACING BEACHES. FURTHER DETAILS CAN BE FOUND IN THE HIGH  
SURF ADVISORY. SURF FALLS A BIT AFTER TUESDAY AND INTO WEDNESDAY  
BEFORE ANOTHER STRONGER SOUTHERLY SWELL (3-4 FT WITH A PERIOD OF 15  
SECONDS) BRINGS ANOTHER ROUND OF ELEVATED SURF FOR THE END OF THE  
WEEK AND INTO THE EARLY WEEKEND. THE HIGH RISK FOR STRONG RIP  
CURRENTS WILL REMAIN FROM SUNDAY THROUGH NEXT WEEK.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...HIGH SURF ADVISORY FROM 5 PM SUNDAY TO 11 PM PDT TUESDAY FOR  
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.  
 
PZ...NONE.  
 
 
 
 
 
PUBLIC...PG  
AVIATION/MARINE/BEACHES...CSP  
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