Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
134 FXUS66 KSGX 091028 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 228 AM PST Tue Dec 9 2025 .SYNOPSIS... High pressure aloft will continue to strengthen through Wednesday while offshore lower level flow weakens. High temperatures will continue to warm through Wednesday, to as much as 15 to 20 degrees above average for portions of the inland valleys. Northeast winds along and below the coastal slopes of the mountains will gust to 35 mph at times into Wednesday morning. For Thursday through next weekend, high temperatures for inland areas will fall by around 10 degrees, but still remain around 8 to 12 degrees above average for the weekend. Patchy night and morning low clouds and fog near the coast could return for Friday into the weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Thursday)... High pressure aloft will continue to strengthen through Wednesday while offshore lower-level flow begins to decrease. High temperatures will continue to warm into Wednesday with high temperatures as much as 15 to 20 degrees above average for portions of the inland valleys and lower coastal slopes of the mountains. High temperatures on Wednesday will range from the lower to mid 70s near the coast to the lower to mid 80s for the inland valleys and for the lower deserts. Gusty northeast winds will continue at times along and below the coastal slopes of the mountains into Wednesday morning with the stronger gusts mostly 35 mph or less. High temperatures on Thursday for the coast into the valleys will cool a few degrees while the mountains and deserts warm another degree or two. Winds on Thursday will be weaker and more localized. && .LONG TERM (Friday through Monday)... The gradual cooling trend will continue into the weekend. Even with the cooling, high temperatures for the weekend will remain around 8 to 12 degrees above average for inland areas. High temperatures will range from the mid to upper 60s near the coast to the mid to upper 70s for the inland valleys with the lower deserts around 80. For the early to middle park of next week, dry weather is expected to continue with the deterministic NBM high temperatures having a gradual warming trend. However, there is greater model spread in the strength of high pressure near the West Coast and the resulting high temperatures. For Ontario, the spread in high temperatures between the 25th and 75th percentile increases from 3 degrees on Thursday and Friday of this week, to 10 degrees for Tuesday and Wednesday of next week. && .AVIATION... 091030Z...Clear and VFR conditions will prevail today and tonight. Northeast winds gusting 25-30 kts along foothills and locally into adjacent valleys. && .MARINE... No hazardous marine conditions are anticipated through Saturday. && .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...17 AVIATION/MARINE...MM