Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
064 FXUS66 KSGX 222247 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 247 PM PST Sat Nov 22 2025 .SYNOPSIS... Widespread precipitation across the lower deserts and adjacent mountain slopes through this morning with showers occasionally making it west of the mountains. Snow levels will rise from 6500 to 7000 ft today. Showers tapering off this afternoon into tonight, with dry conditions expected to return by Sunday. Periods of gusty northeast to east winds will continue through this evening. A gradual warming is expected for next week, with high temperatures returning to above normal by the middle of the week. A weak Santa Ana is possible sometime mid-week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Satellite imagery shows the surface low pressure now a few hundred miles due south of San Diego and slowly propagating eastward. The system is wrapping around mid-level cloud cover and a few more showers into the eastern slopes of the Peninsular Range, San Bernardino Mountains and adjacent deserts. North and east winds for areas south of the Cajon pass and west facing foothill slopes continue to see sustained 15-25 mph winds, gusting 25-40 mph and locally to 45 mph. Winds weaken gradually this afternoon region-wide. Shower activity is set to fully diminish in the coastal basin this afternoon while high resolution models keep a chance for leftover showers for the mountains and areas eastward through overnight tonight. Additional rain amounts range from a few hundredths of an inch to a quarter inch in the areas mentioned above. Sunday, skies clear and high pressure builds and amplifies over the western US, increasing high temperatures into the mid to upper 70s by Tuesday. Behind the larger trough moving into the Eastern US, a surface high pressure of around 1036 mbs will set up in the northern Great Basin, increase the inland-coastal pressure gradient and generating offshore winds as early as Tuesday afternoon according to high resolution guidance. Offshore winds currently are set to peak Wednesday, with moderate confidence for at least a weak Santa Ana Wind event. Current guidance suggests north and east winds sustained at 15-25 mph, gusting 35-45 mph and locally higher, targeting the west facing foothill slopes and below the Cajon Pass, similar to today. With high res guidance available through Tuesday afternoon, confidence in the wind intensity outline above is moderate. The upper-end scenario for a high wind intensity event is capped due to the lack of mid and upper level support and likely will remain confined to the passes/canyons and foothills. High temperatures Wednesday and Thursday will likely be capped as well in the Inland Empire due to the flow of this colder, but modified air due to adiabatic compressional warming. The highest maximum temperatures are most likely to set up in the valleys closer to the coast as a result, approaching near 80F in some spots. Beyond Thursday, ensemble solutions diverge on the track of an upper low into the western US. The prevailing guidance suggests that a cold upper level airmass will dive straight southward (then may even retrograde a bit), close enough to Southern California to tap into surface moisture and ring out a few showers for areas south of Orange County. A slight deviation in the track east or west could change the precipitation chances significantly. && .AVIATION... 222130Z...Very patchy -RA favoring eastern facing mountain slopes and adjacent deserts. FEW-SCT bases 5-7 kft MSL and an OVC layer based 8-10 kft MSL. FG to reduce vis 0-2 SM above 5000 ft MSL and SNSH to reduce vis 0-5SM above 7000 ft, especially along east facing slopes. -RA/SNSH taper off after 23/02z along with vis improvements in the mountains. Only a slight (20%) chance for a leftover SHRA/SNSH for any given area. East to northeast winds gusting 25-35 knots in the coastal foothills and locally into valleys through about 00z Sunday decreasing slowly. && .MARINE... No hazardous marine conditions are expected through Wednesday. && .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...Westerink AVIATION/MARINE...Small