Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
065 FXUS66 KSGX 100421 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 921 PM PDT Thu Oct 9 2025 .SYNOPSIS... A low pressure system off the West Coast will draw moisture from Tropical Cyclone Priscilla northward into the area through Saturday morning, with chances for showers and thunderstorms at times. Cooler with drying and a return of the marine layer early next week. For Tuesday and Wednesday of next week, a low pressure system moving southward along the West Coast will bring a chance of showers along with stronger westerly winds. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Areas of rain were present for much of the afternoon. A rainfall total summary has been headlined on our weather.gov/sandiego homepage. At 9 PM a band of showers was moving from south to northeast across San Diego County, with some isolated light showers elsewhere. Radar and rain gauges are indicating rainfall is mostly light, with pockets of locally moderate rain. Areas of rain will become more isolated overnight, with showers and thunderstorms still expected to develop Friday afternoon and evening in the mountains and deserts. From previous discussion issued at 2 PM October 9... Through tonight, the moisture plume will continue to move up from the south and over the region, with likely a mid level cloud shield and intermittent showers, for even the coastal and inland areas overnight. By tomorrow, the area of low pressure associated with this weakening tropical system will become absorbed into the trough to our south and increasing southerly flow with more instability will give way to a better chance of showers and thunderstorms for tomorrow, especially over the mountains and deserts. An isolated storm over the mountains can`t be ruled out during the afternoon on Saturday, otherwise conditions will become much drier and cooler. The rest of the weekend though the end of next week... The forecast still appear to be on track with the system becoming sheered off towards the east by early Saturday morning, with chances of precipitation diminishing as it does and a temporary drying trend on Sunday. With much more influence from the trough upstream, and the will carry into next week, as a series of deepening troughs bring bouts of light rain and cooler temperatures to southern California. Some of the deterministic models are also hinting at a possible impactful area of low pressure which could potentially given portions of the region very beneficial amounts during the mid part of next week. Temperatures could get much colder, and there could even be some of the higher elevations getting measurable snow for the first time of this year`s rainy season. && .AVIATION... 100300Z....BKN high clouds based 6,000-10,000 feet MSL with Scattered -SHRA and isolated TSRA through the TAF period. Greatest chances for TSRA in the afternoons/evenings over mountains and deserts. VCSH placed in TAFs to cover uncertainty in timing for showers over sites with -SHRA included for areas with higher confidence in timing. Any TSRA could lower cloud bases to 4000 feet MSL briefly, and could bring gusty winds and reduced vis in +RA. Chances for SHRA will move away from coastal sites by 00Z. && .MARINE... Northwest winds occasionally exceeding 20 knots around San Clemente Island during the afternoons and evenings Friday and Saturday. Rain and thunderstorms are expected to stay close to the coast Friday afternoon. && .BEACHES... There is a 5-15% chance of thunderstorms producing lightning Friday, most likely during the afternoons. && .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 UPDATE...CO PUBLIC PREVIOUS DISCUSSION... Stewey AVIATION/MARINE/BEACHES...Villafane