Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
676 FXUS66 KSGX 031557 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 857 AM PDT Thu Apr 3 2025 .SYNOPSIS... Today and Friday will be a little warmer than recent days but still below seasonal averages as the extensive low pressure system persists over the western states. Isolated showers over San Diego County this morning will increase in coverage across the region this afternoon. There is a slight chance of showers for Friday afternoon for the mountains and inland valleys. Then dry and warmer for the weekend with high temperatures warming to around average. Not much change in temperatures for Monday with stronger onshore flow. Then warmer for the middle of next week with high temperatures 10 to 15 degrees above average for inland areas. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This morning...Isolated showers continue over San Diego County. High- resolution models show the showers increasing in coverage across the region this afternoon, with a slight chance for tstms. Through this evening, additional rainfall and liquid-equivalent above the snow level is expected to range from less than one-tenth inch near the coast to one-quarter inch and locally one-half inch for the mountains and valleys. The snow level will rise from 4000-4500 feet to 5000-5500 feet this afternoon/evening, with chances for a few inches of snow above 5000 feet. Today through Saturday...The extensive low pressure that has dominated the synoptic pattern over the western states will slowly shift eastward through Saturday. Temperatures will gradually rise but will likely remain below seasonal averages through Friday. There will be a slight chance for localized showers again Friday afternoon but conditions become drier on Saturday as a sfc high moves into the Great Basin and weak offshore flow develops, with north to northeast winds in the mtns and coastal foothills. High temperatures on Saturday will rise to near seasonal averages in most areas and slightly above seasonal averages in OC and the IE. Dry and warmer on Sunday as a ridge of high pressure moves in from the west. Daytime temperatures will be anywhere from a few to as much as 10 degrees above seasonal averages, reaching the low 80s in the IE and the mid to upper 80s in the low deserts. Not much change from Sun to Mon as the transient ridge is weakened by a trough moving inland to the north, although coastal areas will be a little cooler as onshore flow strengthens. For Tue-Thu...a more robust ridge of high pressure builds over the Southwest, with more significant warming. For Wed and Thu, daytime temperatures will reach the upper 80s to low 90s in the inland valleys and the upper 90s to 100 in the low deserts while coastal areas will reach the mid 70s. These temperatures are 5 to 20 degrees above seasonal averages. && .AVIATION... 031530Z...Coast/Valleys/Coastal Mountain Slopes...SCT-BKN clouds based between 2500-5000 feet MSL, with tops reaching 7000 feet, will continue to be mostly BKN near foothills and in San Diego County this morning. -SHRA most likely in these areas with briefly lower cigs around 2000 feet MSL through 16Z. -SHRA increase in coverage and isold (10-20% chance) TSRA are possible this afternoon 20-01Z in all areas except northern Orange County. Lower cigs around 2500 feet MSL and briefly reduced vis 3-5SM in heavier RA. -SHRA chances decrease after 01Z for most areas, except for Riverside/north San Diego mountains, where chances persist through 04Z. SCT to locally BKN clouds lower to 2500-3500 feet MSL 00-04Z, then gradual clearing after 04Z. SCT to locally BKN clouds 2000-3000 feet MSL could rebuild in coastal areas 10-17Z Fri. Desert Mountain Slopes/Deserts...Mostly clear skies through 18Z. Building clouds based around 5000-8000 feet MSL over mountains will produce scattered -SHRA and isold TSRA with lower bases and vis briefly in pcpcn this afternoon 20-03Z. Gradual clearing after 03Z. && .MARINE... Winds and seas have dropped below hazardous levels and will continue to diminish today. No additional hazardous marine conditions are expected through Monday. && .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