FXUS66 KSGX 231828 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 1128 AM PDT Mon Mar 23 2026 .SYNOPSIS... High pressure aloft will maintain high temperatures through Friday from around 10 degrees above average near the coast to 15 to 20 degrees above average for inland areas. Night and morning coastal low clouds and fog will spread into the western valleys at times. Cooling will begin to spread inland next weekend, but with high temperatures for next Sunday still 10 to 15 degrees above average. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... ...UPDATED AVIATION DISCUSSION... .SHORT TERM (Today through Wednesday)... High pressure aloft will strengthen across southern California through Tuesday, then weaken slightly and briefly on Wednesday. There will be slight day-to-day temperature differences. High temperatures will remain around 10 degrees above average near the coast to 15 to 20 degrees for inland areas. High temperatures will range from the 70s near the coast to the upper 80s to mid 90s for the Inland Empire with the lower deserts in the upper 90s to around 100. Several locations in the mountains, deserts, valleys, and inland Orange County will continue to tie or break daily high temperature records and records for warmest low temperatures. The marine layer is around 1500 feet deep. Night and morning coastal low clouds and fog will spread into the far western alleys at times through the middle of the week. && .LONG TERM (Thursday through Sunday)... Dry weather will continue through next weekend. For next weekend, high pressure aloft will begin to weaken and onshore flow will begin to strengthen as a low pressure system over the eastern Pacific moves toward the West Coast. Cooling will begin to spread inland next weekend. However, high temperatures for next Sunday will still be a around 10 to 15 degrees above average. High temperatures on Sunday will range from the 70s near the coast to mid 80s to lower 90s for the Inland Empire with the lower deserts in the mid 90s to around 100. && .AVIATION... 231800Z...Low clouds based 500-800 feet MSL return to the coastal areas after 04Z, moving 15 miles inland overnight. Vis 2-4 SM over coastal highlands, patchy areas of 5-6 SM for the general coast. Low clouds clear to beaches 17-18Z Tue. Otherwise, mostly clear and VFR conditions will prevail into Tuesday. && .MARINE...No hazardous marine conditions expected through Friday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...17 AVIATION/MARINE...CSP