Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
306 FXUS66 KSGX 181632 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 932 AM PDT Wed Sep 18 2024 .SYNOPSIS... A low pressure system from the northwest will bring chances for light precipitation for Thursday into Friday with more clouds from the coastal waters to the mountains. Low pressure will weaken with dry and much warmer weather for the weekend into early next week with high temperatures warming to a few degrees above average on Sunday and around 5 degrees above average on Monday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... No significant changes to the forecast this morning as the widespread marine layer and generally stable conditions have helped keep the previous forecast on track. previous discussion... 340 AM Wednesday September 18th 2024 The marine layer has decreased in depth to around 3500 feet. The inversion strength is still quite weak with mostly patchy coverage or less of coastal low clouds. High temperatures for today will be a few to around 5 degrees warmer than Tuesday, but still 10 to 15 degrees below average for the mountains and inland valleys. The center of a closed low pressure system from the northwest will move to near Point Conception on Thursday, then move slowly across southern California on Thursday night and Friday and into Arizona on Friday night. High temperatures will be a few degrees cooler on Thursday and only slightly warmer for Friday. This low pressure system will bring chances for light showers at times for Thursday into Friday. Amounts are expected to be light with any precipitation falling for only a limited amount of that time for most areas. Chances for measurable precipitation is generally around 25 to 35 percent for the coast to the mountains with chances for one-quarter inch or more of rainfall around 5 to 10 percent. && .LONG TERM (Saturday through Tuesday)... The center of low pressure over southern California on Friday will move into Colorado on Saturday with lingering low pressure across southern California on Sunday. There is greater spread across California for Monday through Wednesday of next week ranging from weaker low pressure to weaker high pressure. Dry and much warmer weather is expected for the weekend into early next week, but with increasing spread in the high temperature forecasts, especially beyond Monday. With the warming, high temperatures will go from a few to around 5 degrees below average on Saturday to a few degrees above average on Sunday and around 5 degrees above average on Monday and Tuesday. High temperatures for the inland valleys will go from mostly in the 80s on Saturday to the upper 80s to upper 90s on Sunday and the 90s to around 100 for Monday followed by a few degrees of cooling for Tuesday. && .AVIATION... 181500Z...Coast to mountain ridges...Patchy low clouds will continue this morning, mostly in San Diego County, with bases around 2500- 3200 feet MSL and tops to 3300-3500 feet. Local terrain obscurations within that layer. Low cloud decks will break up to SCT 16-18Z. More widespread low clouds will develop along the coast after 00Z and gradually fill in the entire coastal basin overnight into Thursday. Bases will be around 1800-2500 feet MSL starting out but will gradually rise overnight into early Thursday morning to around 2100- 2800 ft MSL. Clouds partially scattering 17-19Z, but may linger in southern San Diego Co. Mountain ridges to Deserts... Mostly clear today and tonight. && .MARINE... No hazardous marine conditions are expected through Sunday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...Suk AVIATION/MARINE...CSP