Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
962 FXUS66 KSGX 290954 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 254 AM PDT Fri Aug 29 2025 .SYNOPSIS... There will be drying through Sunday and warming into early next week to around 5 degrees above average. Monsoonal moisture will return early next week with chances for afternoon and evening thunderstorms for the mountains and deserts increasing through midweek and cooling of high temperatures of 5 to 10 degrees for inland areas by Friday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Sunday)... Drying will continue into the weekend with a warming trend into early next week. High temperatures today of a few degrees below average for inland areas will warm to a few to around 5 degrees above average on Sunday. Sunday high temperatures will range from the mid 70s to lower 80s near the coast to the mid 90s to 102 for the Inland Empire with 106 to 110 for the lower deserts. ECMWF ensemble output shows precipitable water values for the lower deserts lowest on Saturday and Sunday. Chances for measurable rainfall are greatest for the San Bernardino Mountains and will fall to 10 percent today and 5 percent or less for Saturday and Sunday. Night and morning coastal low clouds will gradually return and spread inland into portions of the coastal areas late each night over the weekend. && .LONG TERM (Monday through Thursday)... Warming for the valleys will continue into Tuesday or Wednesday while desert areas slowly cool during the week as monsoonal moisture increases. High temperatures on Monday of around 5 degrees above average will cool by Thursday to within a few degrees of average for most areas to a few degrees below average for the mountains and lower deserts. High temperatures on Thursday will range from the mid 70s to lower 80s near the coast to the 90s for the Inland Empire with 100 to 105 for the lower deserts. ECMWF ensemble output for the lower deserts shows precipitable water increasing for Monday through Wednesday, then plateauing into the first full weekend in September. Chances for mainly afternoon and early evening thunderstorms for the mountains and deserts will return on Monday and continue through much of next week. NBM daily chances for measurable rainfall for Big Bear will increase to around 20 percent for Monday and around 40 percent for each day for Tuesday through Thursday. NBM daily chances for one- half inch or more of rainfall at Big Bear are 5 percent or less. && .AVIATION... 290930Z...Mostly clear skies will prevail today and tonight, but for the following isolated exceptions. Cumulus based at 10000 feet MSL over mountains, along with a slight chance of -TSRA 19-00Z. Also, patchy coastal low clouds based at 800 feet through 15Z this morning and again after 10Z Saturday. && .MARINE... No hazardous marine conditions are expected through Tuesday. && BEACHES... A long-period southerly swell will bring elevated surf Sunday through Monday. Surf of 3-5 feet with occasional sets to 6 feet will present a high rip current risk. && .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...17 AVIATION/MARINE/BEACHES...MM