811  
FXUS66 KSGX 150353  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
853 PM PDT WED MAY 14 2025  
   
SYNOPSIS  
 
DRY AND WARMER THROUGH THURSDAY. COOLER, CLOUDIER, AND WINDIER  
WITH CHANCES OF PRECIPITATION ALONG AND WEST OF THE MOUNTAINS OVER  
THE WEEKEND. WARMER WITH A SHALLOWER MARINE LAYER EXPECTED NEXT  
WEEK.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
EVENING UPDATE...  
PATCHY LOW CLOUDS HAVE DEVELOPED ALONG THE COAST WITH SOME  
SCATTERED HIGH CLOUDS MOVING EAST ACROSS THE REGION THIS EVENING.  
THE 00Z KNKX SOUNDING SHOWS THE MARINE INVERSION BASED NEAR 2200  
FT MSL, DOWN SIGNIFICANTLY FROM AROUND 3800 FT MSL THIS MORNING.  
WITH THE MARINE INVERSION STRENGTHENING, EXPECT LOW CLOUDS TO BE  
MORE ORGANIZED TONIGHT, BUT LIMITED TO THE COASTAL AREAS AND  
WESTERN VALLEYS. BREEZY WEST WINDS IN THE MOUNTAINS AND DESERTS  
WILL WEAKEN OVERNIGHT. NO CHANGES TO THE FORECAST THIS EVENING.  
 
PREVIOUS DISCUSSION...  
WEAK TROUGHING WILL CONTINUE OVER THE WESTERN UNITED STATES THROUGH  
THURSDAY. HIGHS THURSDAY ARE EXPECTED TO BE 3 TO 6 DEGREES WARMER  
THAN TODAY FOR INLAND LOCATIONS. THE MARINE LAYER IS EXPECTED TO GET  
A LITTLE SHALLOWER FOR THURSDAY AND FRIDAY, BUT LOW CLOUDS ARE STILL  
EXPECTED TO REACH INTO THE WESTERN PORTIONS OF THE INLAND EMPIRE. ON  
FRIDAY AN IMPULSE WILL MOVE THROUGH THE MEAN FLOW, DEEPENING THE  
TROUGHING PATTERN OVER SOUTHERN CALIFORNIA, WHICH WILL BRING A FEW  
DEGREES OF COOLING WEST OF THE MOUNTAINS, A DEEPER MARINE LAYER, AND  
AN UPTICK IN WESTERLY WINDS OVER THE MOUNTAINS AND DESERTS.  
 
A DEEPER TROUGHING PATTERN IS EXPECTED FOR THE WEEKEND AS AN UPPER  
LOW PRESSURE SYSTEM DIGS SOUTH ALONG THE WEST COAST. THERE REMAIN  
SOME SLIGHT DIFFERENCES IN HOW FAR SOUTH THE TROUGH DIGS BUT THERE  
IS FAIRLY HIGH CONFIDENCE IN COOLER WEATHER, INCREASED CLOUD  
COVERAGE, AND STRONGER WINDS OVER THE MOUNTAINS AND DESERTS. NBM  
CHANCES FOR WIND GUSTS REACHING OR EXCEEDING 50 MPH ARE 40 TO 60  
PERCENT FOR THE DESERT MOUNTAIN SLOPES AND INTO THE DESERTS, WITH  
CHANCES CLOSER TO 95 PERCENT IN WIND PRONE LOCATIONS IN THOSE  
GEOGRAPHIC AREAS. A RIDGE OF HIGH PRESSURE WILL SET UP OVER THE  
EASTERN PACIFIC FOR THE WEEKEND. MODEL GUIDANCE IS SUGGESTING  
SUBTROPICAL MOISTURE WILL BE PULLED OVER THE RIDGE AND INTO SOUTHERN  
CALIFORNIA AS THE AFOREMENTIONED TROUGH DIGS SOUTH. THE INCREASED  
MOISTURE WILL BRING CHANCES OF PRECIPITATION TO THE AREA. DUE TO THE  
PREDOMINATELY NORTHWESTERLY FLOW, HIGHEST CHANCES OF PRECIPITATION  
ARE ALONG AND WEST OF THE MOUNTAINS FOR SAN DIEGO COUNTY, WITH  
SECOND HIGHEST CHANCES FOR PRECIPITATION ON THE COASTAL SLOPES OF  
THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS. NBM CHANCES OF  
RAINFALL TOTALS EXCEEDING 0.10" SATURDAY NIGHT THROUGH SUNDAY FOR  
SAN DIEGO COUNTY COAST, VALLEY, AND MOUNTAINS AND RIVERSIDE/SAN  
BERNARDINO MOUNTAINS ARE 20 TO 40 PERCENT, WITH THE HIGHEST CHANCES  
ON THE COASTAL MOUNTAIN SLOPES. ELSEWHERE CHANCES ARE 10 PERCENT OR  
LESS. FOR TOTAL RAINFALL ACCUMULATIONS BETWEEN SATURDAY EVENING AND  
SUNDAY IT LOOKS UNLIKELY MORE THAN 0.25" WILL ACCUMULATE FOR SAN  
DIEGO COAST/VALLEYS. FOR THE COASTAL MOUNTAIN SLOPES, IT IS UNLIKELY  
TOTAL RAINFALL WILL EXCEED 0.50".  
 
DRY CONDITIONS ARE EXPECTED TO RETURN TO THE AREA BY MONDAY, AS THE  
TROUGH MOVES EAST AND UPPER LEVEL RIDGE INCHES CLOSER TO THE WEST  
COAST. BY TUESDAY, THE MAJORITY OF ENSEMBLE CLUSTERS SHOW RIDGING  
OVER THE WEST COAST. CURRENT FORECAST FOLLOWS THE NBM WITH WARMING  
TEMPERATURES FOR MONDAY THROUGH WEDNESDAY. BY TUESDAY AND WEDNESDAY,  
HIGH TEMPERATURES WILL BE AROUND AVERAGE FOR THE MOUNTAINS AND  
AROUND 4 TO 8, LOCALLY UP TO 10 DEGREES ABOVE AVERAGE FOR THE COAST,  
VALLEYS, AND DESERTS.  
 
 
   
AVIATION  
 
150330Z...COAST/VALLEYS...CURRENTLY PATCHY LOW CLOUDS 1300-1800 FT  
MSL ALONG THE COAST WILL BECOME MORE WIDESPREAD AFTER 06Z THIS  
EVENING, MOVING UP TO 20 MILES INLAND OVERNIGHT. REDUCED VIS FOR  
HIGHER VALLEY TERRAIN. CLOUDS SCATTER TO THE COAST 16-18Z. LOW  
CLOUDS WITH SLIGHTLY LOWER BASES MOVE INLAND AGAIN AFTER 02Z FRI.  
   
MOUNTAINS/DESERTS  
MOSTLY CLEAR SKIES THROUGH THURSDAY EVENING.  
FEW-SCT CUMULUS FORMING OVER THE MOUNTAIN RIDGES THURSDAY AFTERNOON.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED TODAY THROUGH SATURDAY.  
STRONGER WINDS AND HIGHER SEAS ARE EXPECTED LATE SATURDAY INTO  
SUNDAY. WINDS 15 TO 25 KTS EXPECTED IN THE OUTER COASTAL WATERS AND  
STEEP, WIND-DRIVEN WAVES 7 TO 10 FEET POSSIBLE FOR OUTER COASTAL  
WATERS AND 5 TO 8 FEET FOR INNER COASTAL WATERS. WINDS AND WAVES  
GRADUALLY SUBSIDE LATE SUNDAY INTO MONDAY.  
 
 
   
BEACHES  
 
ELEVATED TO POTENTIALLY HIGH SURF WILL IMPACT BEACHES LATE SUNDAY  
INTO MONDAY. SURF HEIGHT OF 4-7 FEET WITH SETS TO 8 FEET POSSIBLE  
ALONG WEST-FACING BEACHES.  
 
 
   
SKYWARN  
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
PUBLIC...SS/CO  
AVIATION/MARINE/BEACHES...CSP  
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