Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
144 FXUS66 KSGX 071642 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 942 AM PDT Mon Apr 7 2025 .SYNOPSIS... Patchy night and morning low clouds and fog along the immediate coast for the next few days. Fog may be locally dense at times tonight into Tuesday morning. Periods of breezy westerly winds expected over the mountains into the deserts each afternoon and evening today and Tuesday. Temperatures will steadily increase through Thursday or Friday for inland areas. Slightly cooler, cloudier, and potentially windier conditions expected over the weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Low clouds this morning were slow to develop along the coast. At 9 AM, areas of low clouds had finally made it to the immediate coast. Some clearing may occur this afternoon but patchy low clouds and fog will still be prevalent along the coast late tonight into early Tuesday morning. HREF guidance is indicating a 30 to 60 percent of visibility 1 mile or less along portions of the coast. Low clouds and fog will likely continue each night and morning through the week along the coast. Warming conditions are expected through Friday as a ridge builds overhead, the warmest locations will be the Inland Empire and lower deserts. High temperatures will warm a few degrees each day through Thursday for all locations. By Wednesday, high temperatures for the valleys, mountains, and deserts will be 10 to 15 degrees above average. The hottest days of the week will be Thursday or Friday, with highs west of the mountains a degree or two cooler on Friday and an additional degree or two of warming for the deserts on Friday. NBM chances for Palm Springs to reach or exceed 100 degrees is 10 percent Wednesday, 90 percent on Thursday, and 95 percent on Friday. For Riverside chances of reaching or exceeding 95 degrees is 25 percent Wednesday, 90 percent Thursday, and 65 percent Friday. For the most part, HeatRisk is expected to stay minor, with local moderate HeatRisk in the Inland Empire on Thursday. Even with the hot daytime temperatures HeatRisk will be limited by overnight low temperatures falling to the 50s, which should allow for overnight relief from the heat. By Saturday, a trough of low pressure will approach the West Coast which will push the ridge of high pressure to our east. There remains some uncertainty in the track of the incoming low which will impact the temperature, wind, and cloud forecast. Current forecast follows the NBM for Saturday through Monday which has widespread cooling as early as Saturday with increased cloud coverage. && .AVIATION... 071530Z...Satellite shows low clouds based 300-700ft MSL and FG hugging the coastline, pushing up to a few miles inland. Coastal areas will briefly see a drop in VIS down to 1SM, with clearing expected to occur by 16-17z. Mostly clear skies prevail for the rest of the day. Patchy low clouds and fog return tonight based around 300-500ft MSL with VIS reduced to 1-5SM and more coverage than this morning. Localized areas of VIS below 1SM possible. Main time frame for impacts will be 12-16z Tuesday. There is a 40-60% chance of IFR conditions intermittently at KSAN and KSNA, 30-40% for KCRQ. Clearing to the beaches/coast should occur by 17z Tuesday. && .MARINE... Patchy fog will lower visibilities near 1SM each morning through Wednesday. Otherwise, no hazardous marine conditions are expected through Friday. && .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...CO AVIATION/MARINE...Zuber