Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
486 FXUS66 KSGX 112117 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 217 PM PDT Sat Oct 11 2025 .SYNOPSIS... Cooler with drying and a return of the marine layer through the weekend. A low pressure system moving southward along the West Coast will bring stronger westerly winds from Monday onward along with a chance of showers from the coast to the mountains Tuesday into early Wednesday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Drier air from the northwest has filtered into the region with sunny skies prevailing aside from a few low clouds still scattering out of the deserts. Breezy conditions in the mountains and deserts this afternoon and evening as a trough axis passes well to the north. Otherwise, seasonable temperatures and low marine layer clouds rebuilding into coasts and valleys through the weekend with patchy fog for elevated valleys. Starting Monday afternoon, an incoming shortwave trough will begin to make its presence known in the mountains and deserts as winds become elevated to locally strong along deserts and desert slopes. Winds expected to peak Tuesday as the trough passes by with lingering elevated winds into Wednesday. This system will also be accompanied by much cooler temperatures and light precipitation from the coasts to the mountains. As much as 15-20 degrees below average for inland areas. On that note, a dusting of snow will be possible above 7500 feet. There is still uncertainty in rainfall totals, but the track of the low almost directly south from Canada should prevent any significant precipitation totals. Generally expecting the highest amounts for the valleys and mountains north of San Diego County, especially in the western San Bernardino County Mountains where over an inch is forecast. The lower deserts should remain totally rain-shadowed. More seasonable and benign weather returns towards the end of next week as an upper ridge expands into the area. This should allow for the return of nighttime low marine layer clouds for coasts and valleys as the inversion strengthens. Temps will remain slightly below average even as high pressure builds. && .AVIATION... 112040Z....Coasts/Valleys...Patchy low clouds 1400-1800 ft MSL reform after 03Z Sun. Higher confidence (50-60%) of cigs impacting coastal sites. Highest chances will be VCTY KSAN. Clouds scattering back out 15-17Z Sunday. Mountains/Deserts...Mostly clear through the weekend with VFR conditions. Breezy west winds gusting 20-30 kts along desert foothills, high desert, and typically windy spots in low desert until 06Z tonight. Calmer winds expected on Sunday. && .MARINE... Moderate northwest winds in the outer coastal waters will lead to wind gusts occasionally exceeding 20 knots around San Clemente Island this afternoon and evening. No hazardous marine conditions are expected through Monday. Increasing south to southwest winds expected by Tuesday as another weather system approaches the area. && .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...KW AVIATION/MARINE...APR