Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
759 FXUS66 KSGX 061049 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 349 AM PDT Mon Oct 6 2025 .SYNOPSIS... High pressure to the southeast will bring gradually warmer days into Wednesday. The marine layer will decrease in depth with night and morning low clouds not spreading as far into the valleys by Wednesday. For late Thursday into Saturday, moisture from the remnants of Hurricane Priscilla is expected to spread into the southwestern California with chances for showers peaking on Friday. Low pressure from the northwest will bring cooling for next weekend with high temperatures as much as 5 to 10 degrees below average for inland areas next Sunday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Wednesday)... High pressure to the southeast will bring gradually warmer days through Wednesday. With the warming, high temperatures for the coast and valleys will remain a few degrees below average with the mountains and high desert a few degrees above average. High temperatures on Wednesday will range from around 70 near the coast to the 80s for the Inland Empire with the lower to mid 90s for the lower deserts. The marine inversion will gradually strengthen and lower with night and morning coastal low clouds increasing in coverage, but not spreading as far into the valleys for Tuesday and Wednesday. && .LONG TERM (Thursday through Sunday)... Low pressure off the West Coast is expected to direct moisture from the remnants of Hurricane Priscilla into the southwestern states. The NHC track forecast is closest to the ensemble guidance of the ECMWF. For late Thursday afternoon through late Saturday afternoon, the model cluster that is wettest across southern California contains more than half of ECMWF ensemble members. Deterministic NBM output has lower level moisture peaking across the area during the day on Friday. Chances for measurable rainfall peak on Friday at 25 to 35 percent with chances for one inch or more of rainfall in the mountains around 5 percent. The ECMWF Extreme Forecast Index shows the most likely locations for climatologically-unusual rainfall for Thursday night and Friday extends from off the central coast of Baja through northern Baja into the eastern deserts of southern California and into southwestern Arizona. Low pressure to the northwest will bring cooling for next weekend with high temperatures for inland areas next Sunday as much as 5 to 10 degrees below average. && .AVIATION... 060930Z....Coasts/western Valleys...Low clouds near 1500-2000 feet MSL will continue to fill coastal areas and western valleys through sunrise. Scatter out to occur by 16-18Z, but with patchy cigs persisting and intermittent at the coast thereafter. Low clouds with similar bases moving into the coast and western valleys after 02Z overnight into Tuesday. Inland Valleys/Mountains/Deserts...Mostly clear and VFR conditions will continue today and tonight. && .MARINE... No hazardous marine conditions are expected through Friday, except there is a slight chance of thunderstorms near the coast on Friday afternoon. && .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