785  
FXUS66 KSGX 202027  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
127 PM 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...  
   
SHORT TERM  
 
BESIDES SOME VERY THIN CIRRUS (UPPER LEVEL CLOUDS), CLEAR SKIES  
ARE PRESENT ACROSS THE REGION, WITH AFTERNOON HIGH TEMPERATURES  
NEAR TO SLIGHTLY ABOVE AVERAGE. EXCELLENT WEATHER, IN THIS  
FORECASTER'S OPINION, TO EAT FAR TOO MUCH CHOCOLATE. THE MARINE  
CLOUD LAYER WILL REDEVELOP LATE THIS EVENING, LIKELY PATCHY AT  
FIRST BEFORE BECOMING MORE WIDESPREAD IN THE SMALL HOURS OF MONDAY  
MORNING. THESE CLOUDS WILL CLEAR MONDAY MORNING AT A SIMILAR TIME  
TO THIS MORNING, FOLLOWED BY ANOTHER MOSTLY SUNNY DAY.  
 
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 IN 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 COMPARED TO TODAY 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 (MOST LIKELY EARLY FRIDAY MORNING) BUT WITH OTHERWISE  
VERY LIKELY DRY WEATHER. AFTERNOON AND EVENING BREEZES WILL  
STRENGTHEN SLIGHTLY AGAIN IN THE MOUNTAINS AND DESERTS MID TO LATE  
WEEK.  
 
 
   
LONG TERM  
 
SOME DEGREE OF LARGE-SCALE CYCLONIC FLOW CONTINUES TO BE LIKELY  
FOR AT LEAST THE FIRST PART OF THE WEEKEND, MEANING COOLER  
TEMPERATURES WOULD CONTINUE. GLOBAL ENSEMBLE MEMBERS ARE 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, WHILE OTHERS INDICATE CONTINUED COOL  
WEATHER WITH A DEEPER MARINE LAYER THROUGH THE WEEKEND AND PERHAPS  
MONDAY. MODELS ARE IN BETTER AGREEMENT IN AT LEAST A WEAK RIDGE  
WITH WARMER TEMPERATURES LOCALLY BY EARLY THE NEXT WEEK.  
 
 
   
AVIATION  
 
202000Z....COASTS/VALLEYS...FEW-SCT LOW CLOUDS 900-1500 FT MSL THIS  
AFTERNOON WITH FEW HIGH CLOUDS AT 25000 FT MSL. WIDESPREAD LOW CLOUD  
COVERAGE IS EXPECTED TONIGHT. LOW CLOUDS WILL RETURN TO COASTAL  
AREAS AND SPREAD INTO THE WESTERN VALLEYS 02-06Z MON. BASES ARE  
EXPECTED TO BE 700-1200 FT MSL. THERE IS A 20 PERCENT CHANCE OF LOW  
CLOUDS REACHING KONT TONIGHT, MOST LIKELY 12Z OR LATER. LOCAL VIS  
RESTRICTIONS 2-4SM NEAR HIGHER COASTAL TERRAIN AND IN THE VALLEYS.  
LOW CLOUDS AND VIS RESTRICTIONS EXPECTED TO CLEAR TO THE BEACHES 16-  
18Z MON.  
 
MOUNTAINS/DESERTS...CLEAR SKIES WITH UNRESTRICTED VIS PREVAILING  
THROUGH MONDAY.  
 
 
   
MARINE  
 
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH FRIDAY.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...NONE.  
 
 
 
 
 
PUBLIC...CSP  
AVIATION/MARINE...CO  
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