Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
577 FXUS66 KSGX 072027 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 127 PM PDT Mon Apr 7 2025 .SYNOPSIS... Patchy low clouds and fog along the immediate coast for the next few days. Fog may be locally dense at times. Periods of breezy westerly winds expected over the mountains into the deserts in the afternoon and evening today and Tuesday. Temperatures will steadily increase through Thursday and Friday for inland areas. Slightly cooler, cloudier, and windier conditions expected over the weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... At 1 PM, patches of low clouds were still lingering along the immediate coast. Where those low clouds are intersecting land visibility was under 1 mile, elsewhere skies are crystal clear. There is still time for clearing to occur this afternoon but patchy low clouds and fog will redevelop along the coast late tonight into early Tuesday morning. HREF guidance is indicating a 30 to 60 percent chance of visibility 1 mile or less along portions of the coast overnight. 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. Highs up to 20 degrees above average expected for Thursday and Friday which will be the hottest days of the week. Highs west of the mountains will be similar to Thursday or a degree or two cooler on Friday with an additional degree or two of warming expected 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 and 60s, 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 and a slight uptick in winds over the mountains and deserts. && .AVIATION... 071930Z...Satellite shows a few low clouds based 300-700ft MSL off the Orange County coast, which should be clearing through 21z. 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 slightly more coverage than this morning. Localized areas of VIS below 1SM possible at times. 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