269 FXUS66 KSGX 010940 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 240 AM PDT Wed Oct 1 2025 .SYNOPSIS... Warming will spread inland for today and Thursday with Thursday high temperatures a few to around 5 degrees below average. A low pressure system moving inland through California on Friday will bring stronger onshore flow with southwest to west winds for the mountains and deserts gusting to 30 to 40 mph with isolated gusts to around 50 mph on the east slopes of the mountains. There will be cooling of as much as 4 to 8 degrees for the mountains on Friday with continued cooling of a few more degrees for the deserts on Saturday. Low pressure from the north will spread more cooling inland for Sunday and Monday with Tuesday a few degrees warmer. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Friday)... High pressure to the southeast will bring a few degrees of warming for today and Thursday with high temperatures on Thursday a few degrees below average to around 5 degrees below average for the valleys and inland Orange County. Thursday high temperatures will range from around 70 near the coast to the lower to mid 80s for the Inland Empire with the mid 90s for the lower deserts. A low pressure system from the northwest moving into California and Nevada on Friday will bring stronger onshore flow and deepening of the marine layer with high temperatures as much as 4 to 8 degrees cooler for the mountains and high desert. Southwest to west winds for the mountains and deserts will gust to 30 to 40 mph, locally to around 50 mph along the east slopes of the mountains and in the northern Coachella Valley below the San Gorgonio Pass. Coastal low clouds will be much patchier early this morning as the marine layer slowly decreases in depth through Thursday. Coverage of low clouds will begin to increase for tonight into Thursday morning with greater inland spread into the valleys for late Thursday night into Friday morning as the marine layer begins to deepen. && .LONG TERM (Saturday through Tuesday)... The low pressure system moving inland through California and Nevada will weaken and accelerate inland on Saturday. High temperatures for the deserts will continue to cool a few degrees while the coast, valleys, and mountains warm a few degrees. High temperatures on Saturday will range from the lower 70s near the coast to around 80 for the Inland Empire with around 90 for the lower deserts. A low pressure system from the north will spread cooling inland for Sunday and Monday with Monday high temperatures as much as 8 to 12 degrees below average for the mountains, valleys, and inland Orange County. High temperatures on Monday will range from around 70 near the coast to the 70s for the Inland Empire with the mid to upper 80s for the lower deserts. Tuesday high temperatures will warm a few degrees, but still be as much as 5 to 10 degreesbelow average for the mountains, valleys, and inland Orange County. && .AVIATION... 010930Z....Coast...Areas of low clouds will develop with bases around 1200-1800 feet MSL, especially vcnty KSNA this morning. Low confidence in cigs for San Diego County. Any cigs will scatter out by 15-17Z. Areas of low clouds based around 1000-1500 feet MSL gradually developing after 04Z into early Thursday. Valleys/Mountains/Deserts...Mostly clear and VFR conditions today and tonight. && .MARINE... No hazardous marine conditions are expected through Sunday. && .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
NWS SGX Office Area Forecast Discussion