Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
004 FXUS66 KSGX 110950 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 250 AM PDT Sat Oct 11 2025 .SYNOPSIS... Residual moisture from Priscilla will continue to bring light showers to portions of San Diego and Riverside Counties this morning. By mid-morning the showers will move to the northeast and clouds will decrease through the afternoon. Cooler with drying and a return of the marine layer for the next two days. For Tuesday and Wednesday of next week, a low pressure system moving southward along the West Coast will bring a chance of showers from the coast to the mountains, along with stronger westerly winds. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This morning...The upper level circulation from Priscilla is no longer discernible as it has been absorbed in the southwest flow between the low over WA/OR and the high near the MX/TX border. The bulk of the moisture from Priscilla is well to the east of SoCal but some residual moisture will continue to bring a few light showers to portions of San Diego and Riverside Counties through about mid-morning. Any further accumulations are not expected to exceed one tenth inch. Drier air from the northwest will bring fair and locally breezy conditions to SoCal for this afternoon through Monday as the low over WA/OR moves inland becoming an open wave over the Rockies by Sunday. The westerly winds will be strongest this afternoon, with the wind-prone locations of the mtns and deserts likely to see wind gusts of 35-40 mph. Fair and mild conditions will prevail through Monday as broad low pressure troughing covers the western US, although temperatures will remain several degrees below seasonal averages. The marine layer low clouds and fog will return to the coastal areas and valleys during the nights and mornings. A reinforcing shortwave trough moving south out of western Canada on the upstream side of the mean trough will form a closed upper low over the WA coast by Sunday night. Numerical model solutions are coming into better agreement through Wed and project the upper low to move into central CA late Tue before moving eastward into NV/UT by Wed. This system will bring colder air from the north along with stronger westerly winds and chances for precipitation Tue-Wed. Showers could move in from the northwest as early as Tue morning and continue into Wed morning. Forecast details are still somewhat uncertain but current rainfall estimates are for a few hundredths of an inch over San Diego County to nearly an inch over the western portions of the San Bernardino Mountains. The lower deserts are likely to be rain-shadowed which is common for early season systems moving in from the northwest with limited moisture, most of which will have been rained out before the system reaches SoCal. A dusting of snow is possible in wilderness areas of the San Bernardino Mountains above resort levels. Showers should end by mid-day Wed as the system moves inland. Tue and Wed will likely be the coolest days with daytime temperatures as much as 15-20 degrees below normal for inland areas. The low deserts could be up to 10 degrees below normal. Winds will peak Mon night/Tue morning, with the wind-prone locations of the mtns and deserts potentially seeing wind gusts of 50-55 mph. Fair and gradually warmer towards the end of next week as the system moves off to the east and high pressure expands eastward over the west coast. Saturday will likely be the warmest day with daytime temps still as much as 5-9 degrees below normal in the inland valleys. The marine layer could return with low clouds and fog for the coastal areas and valleys during the nights and mornings. && .AVIATION... 110905Z....Coasts/Valleys...ISO -SHRA over San Diego County will taper off by 11Z. Low clouds 1200-1500 ft MSL are likely (70% chance) to form towards 12Z in parts of coastal San Diego County and northwest Orange. These will be patchy and have a moderate chance (40%) of impacting KSAN/KCRQ. Low clouds clearing 15-17Z, followed by VFR conditions and mostly clear skies through the evening. Patchy low clouds 1400-1800 ft MSL reform after 02Z Sun, with low to moderate chances of impacting coastal sites (20-40% chance). Mountains/Deserts...ISO -SHRA over San Diego County will taper off by 11Z. VFR conditions and mostly clear skies through period. Breezy west winds gusting 20-30 kts along desert foothills, high desert, and typically windy spots in low desert 18-05Z. && .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...PG AVIATION/MARINE...CSP