Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
462 FXUS66 KSGX 080402 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 902 PM PDT Tue May 7 2024 .SYNOPSIS... Blustery northwest winds in the mountains and deserts this evening will diminish overnight. On Wednesday, weak offshore flow will bring a warmer day to the valleys along with breezy northeast winds to the mountains and deserts. A coastal eddy will bring night and morning marine layer clouds to the coastal zones each day this week. Seasonally warm weather is forecast Thursday through Saturday with an upper level trough stalled over the Southwest. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .Evening Update... GOES imagery shows low clouds beginning to build in around the greater San Diego area near the coast. Our evening forecast is on track for clouds to push around 15 to 20 miles inland through the night with patchy fog expected for valleys away from the immediate coast. West winds continue to be gusty near 25-35 MPH for many mountain passes and desert slope regions. Expect winds to weaken, and then turn weakly offshore with breezy winds by morning for coastal slope areas. Otherwise, we can expect little day to day changes with dry weather and seasonal temperatures. Slight warming is possible by the weekend with NBM probabilities showing around 20-40% chance of triple digit temperatures across the Coachella Valley. .Previous Discussion (130 PM Tuesday)... Low clouds will move into the coastal zones as a coastal eddy spins up tonight. The clouds will dissipate in most areas by late morning, but linger at some of the beaches through the afternoon. The eddy continues Wednesday night with low clouds returning to the coastal zones before retreating back the coast in the afternoon, again lingering near the beaches most of the day. Gusty northwest winds in the mountains and deserts this evening will diminish overnight. The northwest flow aloft shifts northeast Wednesday and Thursday as a closed low forms over the Nevada. This offshore flow pattern will bring a period of north to northeast winds to the deserts and the mountains tomorrow, some of which will funnel through the Cajon Pass and the San Gorgonio Pass into the Inland Empire. From Thursday through Saturday the models show a large closed upper low over the Southwest meandering slowly eastward from Nevada on Friday to Utah. This places SoCal on the west side of the upper low with predominately weak north to northeast flow aloft and overall seasonal weather. && .AVIATION... 080340Z...Stratus with bases 1500-1800 ft MSL and tops to 2200 ft MSL will spread north along the coast and 15-20 mi inland overnight as a coastal eddy develops, potentially spreading into far southern portions of the Inland Empire. Local vis 4-6 SM in BR/HZ where stratus nears terrain in the valleys. Clouds clearing inland 15-17Z and coastal areas 17-20Z, with limited clearing along the immediate coast. Clouds moving back inland across San Diego County after 09/02Z and into Orange County after 09/06Z. Otherwise mostly clear with unrestricted vis through Wednesday evening. West winds with sfc gusts 20-30 kt continuing across the mountains and deserts through around 10Z Wed. Winds turn northerly and spread into the Morongo and Cajon Passes with local gusts 30-40 kt 12-18Z Wed, weakening 18-20Z. MOD up/downdrafts and pockets of LLWS possible over and downwind of the mountains through late Wed morning. && .MARINE... No hazardous marine conditions are expected through Sunday. && .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...APR/Moede AVIATION/MARINE...SS