Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
411 FXUS66 KSGX 140347 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 847 PM PDT Mon May 13 2024 .SYNOPSIS... Night and morning low clouds will be present across the coast and valleys every day this week, with some beach locations seeing minimal clearing each day. A slight chance of light showers develops Wednesday afternoon in the mountains. Slow warming for Thursday and Friday, followed by slight cooling for the upcoming weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .EVENING UPDATE... Marine layer low clouds have return to the coastal areas and even have begun to creep into some of the far western valleys this evening. Clouds will spread into portions of the inland valleys again tonight. Elsewhere there are scattered high clouds moving around the northeast side of the upper low that is currently off the Southern CA coast. Breezy southwest to west winds across the mountains and deserts are currently gusting to around 25 to 35 mph, locally up to 45 mph near the San Gorgonio Pass, and will gradually weaken overnight. No forecast updates this evening. The only thing of note is some potential for light precipitation across the high desert and perhaps into the mountains late Wednesday into Thursday as the upper low moves to our east some wrap around moisture spreads across So Cal. However, there is not much agreement amongst ensemble members, so confidence in any such event occurring is low. .PREVIOUS DISCUSSION... An upper level low will weaken and pass over the region Tuesday night and Wednesday. This could lead to small chances for rain showers over the northern mountains Wednesday afternoon, but anything that does fall will be light. Low clouds will remain present across the coast and valleys each night and morning, with some clouds hanging around beach communities into the afternoons. For the second half of the week, ridging builds over the eastern Pacific and Pacific Northwest, and ensemble guidance is showing building positive height anomalies. Slow warming is expected on Thursday and Friday, with Friday likely being the warmest day of the week, when highs will range 4-8 degrees above normal across the mountains and deserts. Persistent low cloud cover west of the mountains will moderate the warming, with highs remaining slightly below normal through the end of the week. Another closed low forms to our west late this week into this weekend, spreading slight cooling inland starting on Saturday. No widespread precipitation is expected over the next week. && .AVIATION... 140330Z...Coast/Valleys...BKN-OVC low clouds with bases 1000-1500 ft MSL are slowly pushing inland from the coast as of 03Z. Cigs expected to reach KONT and KSBD after 08Z. Local vis reductions of 2- 5 SM in the valleys and 0-5 SM where clouds obscure higher terrain. Low clouds expected to clear inland 16-18Z. Slow clearing is expected for the coast Tue, with only partial/intermittent clearing possible. Bases will be higher Tuesday evening, closer to 1500-2000 FT MSL with low clouds moving back inland again around or shortly after 00z. Mountains/Deserts...Mostly clear with unrestricted VIS into Tue. SCT/BKN clouds over the mountains with bases around 9000 feet MSL through 02Z Tue. West winds gusting locally 25-35 kts through mountain passes into adjacent desert slopes 23Z Mon-12Z Tue. && .MARINE... No hazardous marine conditions are expected through Saturday. && .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...SS AVIATION/MARINE...Adams