867  
FXUS66 KSGX 201608  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
908 AM PDT SUN APR 20 2025  
   
SYNOPSIS  
 
DRY AND WARMER THROUGH EARLY NEXT WEEK WITH HIGH TEMPERATURES  
NEAR TO AROUND 5 DEGREES ABOVE NORMAL INLAND BY MONDAY. GRADUAL  
COOLING FOLLOWS TUESDAY THROUGH SATURDAY. AREAS OF NIGHT AND  
MORNING LOW CLOUDS AND FOG CONTINUING THROUGH NEXT WEEK, BECOMING  
MORE WIDESPREAD TOWARDS THE MIDDLE OF THE WEEK AS THE MARINE LAYER  
DEEPENS. AFTERNOON AND EVENING WINDS WILL STRENGTHEN SLIGHTLY  
ACROSS THE MOUNTAINS AND DESERTS FOR THE LATTER HALF OF THE WEEK.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
LOW, MARINE LAYER CLOUDS FINALLY MADE THEIR WAY INLAND TO AREAS  
10-15 MILES FROM THE COAST EARLIER THIS MORNING, BUT ARE QUICKLY  
DISSIPATING FROM LAND AREAS. SOME WISPY HIGH CLOUDS WILL START TO  
MOVE IN FROM THE WEST MID- TO LATE-AFTERNOON TODAY, BUT MOSTLY  
SUNNY SKIES WILL PREDOMINATE THROUGH THIS EVENING DESPITE THEM.  
EXPECT HIGH TEMPERATURES TO BE A COUPLE OF DEGREES (COASTAL AREAS)  
TO UP TO 10 DEGREES (DESERTS) WARMER TODAY COMPARED TO YESTERDAY,  
BRINGING TEMPERATURES TO NEAR TO SLIGHTLY ABOVE AVERAGE TODAY. THE  
MARINE CLOUD LAYER WILL REDEVELOP LATE THIS EVENING, LIKELY PATCHY  
AT FIRST BEFORE BECOMING MORE WIDESPREAD IN THE SMALL HOURS OF  
MONDAY MORNING.  
 
FOR THE NEXT WEEK, WEAKLY CYCLONIC FLOW WILL BE IN PLACE ALOFT,  
WITH A SERIES OF WEAK SHORTWAVES BRINGING COOLING TEMPERATURES, A  
DEEPENING MARINE LAYER, AND BRISKER AFTERNOON AND EVENING BREEZES  
(MOSTLY TO THE MOUNTAINS AND DESERTS). MONDAY WILL SEE  
TEMPERATURES SIMILAR TO TODAY, WITH SLIGHT COOLING ALONG THE COAST  
AND SLIGHT WARMING FOR THE DESERTS, AND STRONGER AFTERNOON AND  
EVENING BREEZES IN THE MOUNTAINS AND DESERTS. RINSE AND REPEAT  
TUESDAY WITH ANOTHER DEGREE OR TWO DROP IN HIGH TEMPERATURES FOR  
THE COASTS AND VALLEYS, AND DEGREE OR TWO RISE FOR THE MOUNTAINS  
AND DESERTS. THE COOLING TREND THAT STARTED ALONG THE COAST WILL  
THEN SPREAD INLAND FOR THE REST OF THE WEEK, WITH SLIGHTLY TO  
ABOUT 10 DEGREE BELOW AVERAGE TEMPERATURES THROUGH MOST OF THE  
REGION BY THU-FRI. MARINE LAYER LOW CLOUDS WILL GET PROGRESSIVELY  
DEEPER AND FURTHER INLAND EACH NIGHT, WITH AREAS OF DRIZZLE UNDER  
THE MARINE LAYER POSSIBLE BUT WITH OTHERWISE DRY WEATHER.  
AFTERNOON AND EVENING BREEZES WILL STRENGTHEN SLIGHTLY AGAIN IN  
THE MOUNTAINS AND DESERTS MID TO LATE WEEK.  
 
SOME DEGREE OF LARGE-SCALE CYCLONIC FLOW CONTINUES TO BE LIKELY  
FOR THE FIRST PART OF THE WEEKEND, MEANING COOLER TEMPERATURES  
WOULD CONTINUE, WITH GLOBAL ENSEMBLE MEMBERS SPLIT ON WHEN A LOW  
PRESSURE SYSTEM WILL MOVE INTO (AND OUT OF) THE GREAT BASIN. THE  
EARLIER/FASTER TRACKING MODELS INDICATE RIDGING (AND WARMING)  
STARTING SUNDAY, WITH BETTER AGREEMENT IN AT LEAST A WEAK RIDGE  
WITH WARMER TEMPERATURES LOCALLY BY EARLY THE NEXT WEEK.  
 
 
   
AVIATION  
 
201600Z....COASTS/VALLEYS...LOW CLOUDS 500-1000 FT MSL CURRENTLY  
WITHIN 10 MILES OF THE COAST. LOW CLOUDS SHOULD CLEAR TO THE BEACHES  
BY 17Z, WITH THE POTENTIAL FOR LOCAL PATCHES OF LOW CLOUDS TO LINGER  
INTO THE AFTERNOON. LOW CLOUDS ARE EXPECTED TO BE MORE WIDESPREAD  
TONIGHT, RETURNING TO COASTAL AREAS AND SPREADING INTO THE WESTERN  
VALLEYS 02-06Z MON. BASES LIKELY 700-1200 FT MSL. LOW CLOUDS  
EXPECTED TO CLEAR TO THE BEACHES 16-18Z MON.  
 
MOUNTAINS/DESERTS...CLEAR SKIES WITH UNRESTRICTED VIS PREVAILING  
THROUGH MONDAY MORNING.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH THURSDAY.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
PUBLIC...CSP  
AVIATION/MARINE...CO  
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