Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
226 FXUS66 KSGX 210955 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 255 AM PDT Sat Sep 21 2024 .SYNOPSIS... A warming trend is expected through Monday. The marine layer will become shallower into early next week, becoming more confined to the coast and portions of the western valleys. For Tuesday through the end of the week, minor daily fluctuations in high temperatures are expected. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... High temperatures today are expected to be warmer than Friday for most locations. Highs in the mountains and deserts are forecast to be 10 to 15 degrees warmer than Friday, with 5 to 10 degrees of warming expected for the valleys. Coastal areas will be the only locations with temperatures similar to a degree or two cooler than Friday. Conditions will continue to warm each day through Monday. By Monday, most inland locations will have highs 3 to 7 degrees warmer than average. For Tuesday, temperatures for most locations west of the mountains will be similar to a degree or two cooler than Monday with an additional few degrees of warming expected in the deserts. For the middle to end of next week, Southern California is expected to be in between an upper level low to the west and an upper level high to the east. There is still uncertainty surrounding the placement and amplitude of these weather systems creating some uncertainty in the temperature forecast, especially for the coast and valleys. Current forecast has near to slightly below average temperatures for the coast and valleys and slightly above average temperatures for the mountains and deserts Wednesday through next Saturday. The marine layer will become shallower by Sunday. Marine layer low clouds and fog will become more confined to coastal areas and only portions of the western valleys. The upper level pattern will have an influence on marine layer cloud coverage for the middle to end of the week. Current forecast maintains low clouds along the coast and portions of the western valleys into next weekend. && .AVIATION... 210900Z...Coasts/Valleys...Low marine stratus (based around 1500- 2000ft MSL, topped to 1800-2300ft MSL) have filled in across Orange County and the northern San Diego County coasts with lingering clouds across the coastal mountain slopes near 4000ft MSL. The low marine stratus should gradually fill in to the southern San Diego County coasts and into KSAN by 11-12z this morning. Localized VIS reductions possible to 1-3SM in BR for higher coastal terrain and valleys. Scattering out will occur for most locations by 18-19z, though some stratus may linger near the beaches through the afternoon. Low stratus builds in again for coastal sites around 03- 06z this evening with bases near 800-1200ft MSL. Mountains/Deserts...Mostly clear skies with unrestricted VIS expected through Saturday evening. && .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...CO AVIATION/MARINE...Munyan