Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
578 FXUS66 KSGX 280410 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 910 PM PDT Mon May 27 2024 .SYNOPSIS... Minor day-to-day changes into early next week with high temperatures generally about 5 degrees above average for the deserts and a few degrees below average for the coast and valleys. Marine layer low clouds will extend into portions of the valleys during the nights and mornings. There will be gusty southwest to west winds in the mountains and deserts each late afternoon and evening with gusts to around 25 to 40 mph in favored locations. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Marine layer low clouds, which stuck to many of the coastal areas through the day, have begun to slowly push back inland. The 00Z KNKX sounding shows the marine inversion based near 2100 ft MSL, deep enough for clouds to spread into the inland valleys again overnight. Clouds should clear inland by late Tuesday morning, but clinging to the beaches and up to a few miles inland again. Further inland, breezy conditions continue through the passes where winds are gusting to around 20-30 mph with isolated gusts to 40 mph. Winds will diminish overnight. No updates to the forecast this evening as the weather more or less remains the same for the next week. Extensive high pressure to the south will exert some influence as it competes with the trough extending from an intense low pressure system in the Gulf of Alaska. The result will be minor height rises, a shallower marine layer with less extensive low clouds during the nights and mornings, and generally higher daytime temperatures - mainly inland away from the marine layer influence. Highs will generally be around 3 to 5 degrees above normal in the deserts and 3 to 5 degrees below normal in the coastal areas and valleys each day through the weekend. A low pressure trough moving inland to our north on Wed could bring a slight deepening of the marine layer and minor cooling - mainly west of the mtns. Temperatures rebound on Thursday and remain persistent through the weekend. The marine layer will be around 2000-2500 feet deep, varying slightly each day, with night and morning low clouds spreading inland into portions of the valleys. There will be gusty southwest to west winds for the mountains and deserts for each late afternoon through late evening with the stronger gusts each day to around 25 to 40 mph. && .AVIATION... 280330Z...Coast/Valleys...Areas of low clouds within 20 miles of the coast will spread 40 miles inland by 08Z Tue and cover most valley locations by 12Z Tue. Bases will be mostly 1000-1500 ft MSL with tops to 2000 ft MSL. Local VIS 1-3 miles will occur in BR in the valleys 08Z-16Z Tue. Most valleys will clear 15Z-18Z Tue with coastal areas clearing 18Z-21Z Tue with some locations within 5 miles of the coast having BKN CIGs after 21Z Tue. Stratus will spread back inland Tue evening. Mountains/Deserts...Areas of W-SW surface gusts 25-35 knots will occur trough 13Z Tue on the desert mountain slopes and locally into the deserts, with a slight decrease through 22Z Tue, then another increase after 22Z Tue with areas of gusts 30-40 knots. Otherwise, mostly clear skies with unrestricted VIS will continue through Tue evening. && .MARINE... West to northwest winds will gust around or slightly above 20 knots Wednesday afternoon and evening in the outer coastal waters (30 to 60 NM from the coast). Otherwise, no hazardous marine conditions are expected through Saturday. && .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 AVIATION/MARINE...Maxwell