Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
660 FXUS66 KSGX 232140 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 140 PM PST Sun Nov 23 2025 .SYNOPSIS... Mostly sunny and dry for the remainder of today. A gradual warming is expected through Thanksgiving, with high temperatures returning to above normal by the middle of the week. Weak to moderate Santa Ana winds Tuesday through Thanksgiving, peaking on Wednesday. Another trough of low pressure will bring cooler weather with a 15 to 35 percent chance of showers sometime next Saturday afternoon into Sunday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This afternoon...Temperatures are several degrees warmer than at this time yesterday, especially in the mtns,deserts and inland valleys. Sfc pressure gradients are trending onshore and a sea breeze has developed with onshore winds gusting 15-20 mph in portions of the coastal areas and inland valleys. Skies are clear except for a few fair- weather cumulus over the mountains and small patches of stratus just off the coast. Overnight, the cumulus will dissipate and the stratus will likely increase in coverage along the coast, spreading several miles inland with weak onshore flow. From previous discussion... A pattern change will see the western US become dominated by a building ridge of high pressure aloft at least through Thanksgiving, along with periods of offshore flow as sfc high pressure moves into the Great Basin. This will bring dry conditions and a warming trend through midweek. The offshore pressure gradients will bring Santa Ana winds for Tuesday through Thanksgiving. The winds will be strongest on Wednesday with northeast to east winds gusting 35-50 mph in the wind-prone areas of the passes/canyons and coastal slopes. Humidities in the inland valleys will drop into the high teens to low 20% range but the fire danger will be mitigated by the rains over the last week. It looks like Wed and Thu will be the warmest days, with daytime high temperatures in the low deserts, valleys and coastal areas reaching the 70s to low 80s. High temperatures could be as much as 11-14 degrees above seasonal averages in the inland valleys. For Friday into next weekend...The ridge of high pressure will be weakened and displaced by an extensive area of low pressure. This will bring a return of cooler, unsettled weather with onshore flow, higher humidity and chances for widespread precipitation next Sat and Sun. There is still considerable uncertainty surrounding the track and timing of multiple shortwave troughs but at this time, about 55% of ensemble members show precipitation sometime between Sat and Sun. && .AVIATION... 232000Z...Mostly clear skies and VFR prevailing region-wide through this evening. Coasts/Valleys...Isolated low clouds based 1000-1500 ft MSL will form in areas after 02Z Mon, becoming more widespread if still patchy along coastal and inland areas after 06Z Mon. VIS 0-5SM where clouds intersect terrain and initially in eastern valleys. 40% chance for CIGs at KSAN/KCRQ by 06Z, KSNA by 10Z. Increasing chance (35%) for cigs to approach into the vicinity of KONT after 10z. Meanwhile, bases and cloud tops lower slightly down to 700-1200 ft MSL after 10z in SD county. VIS reductions 0-5SM progressively move into lower elevations and western valleys as bases lower through 15z Mon. Scatter out 16-18z Mon, then VFR region-wide Monday afternoon. VFR conditions continue for the mountains and deserts through Monday afternoon. && .MARINE... No hazardous marine conditions are expected through Thursday. && .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...Westerink