Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
110 FXUS66 KSGX 140416 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 916 PM PDT Thu Jun 13 2024 .SYNOPSIS... Warming conditions into Friday and Saturday, followed by another round of near to below average temperatures for Sunday into the middle of next week. Night and morning low clouds and fog can be expected each day along the coast and into portions of the valleys. Periods of gusty westerly winds in the mountains and deserts, combined with dry conditions will create elevated fire weather conditions through the weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Update... A 584 DM low is passing over Southern California this evening. Dynamic forcing from the low has produced isolated showers and thunderstorms in eastern San Bernardino County and along the California-Nevada border this evening, well to the east of our area. Height rises fill in behind the low, leading to a more shallow marine layer that will not progress as far inland as previous mornings, and warming temperatures. The warm up starts tomorrow with highs rising 5-10 degrees above normal across the mountains and deserts, and 2-5 degrees above in the valleys. Further warming is expected on Saturday when a moderate heat risk develops across the valleys and major heat risk sets in across the deserts. Previous Discussion (Issued 146 PM PDT Thu Jun 13 2024)... As of 1:30 PM, low clouds had mostly cleared, with a few patches of low clouds lingering along portions of the San Diego County coast. Overall, temperatures at 1:30 PM were running 2 to 7 degrees cooler than this time yesterday in the valleys, mountains, and High Desert. Temperatures at the coast and in the lower deserts were the same to a few degrees warmer than yesterday. Marine layer low clouds will move back inland and reach into portions of the Inland Empire late tonight or early Friday morning. A brief warming trend is expected for Friday and Saturday as a weak ridge of high pressure builds over southeastern California, southern Nevada, and western Arizona. This will result in noticeable warming, especially for inland areas which will peak on Saturday. High temperatures will be 8 to 12 degrees above average with hottest temperatures in the lower deserts to around 115 and in the Inland Empire to around 100. Moderate heat risk is expected in the Inland Empire on Saturday and moderate to locally major heat risk is expected in the low deserts Friday and Saturday. During this time its recommended that folks stay hydrated and limit outdoor physical activities between 10am and 5pm (if possible). Sunday and Monday will be cooler as a low pressure system moves inland through the western states. On Monday, high temperatures for the mountains, inland valleys, and High Desert will be 5 to 10 degrees below average. Highs in the low deserts will be a degree or two below normal meaning highs will be around 100-103 degrees. High temperatures on Tuesday may be a few degrees warmer with a warming trend continuing through the following weekend. Night and morning low clouds and fog for the weekend into next week will continue along the coast each day and into portions of the valleys at times. && .AVIATION... 140400Z...Coast/Valleys...Low clouds increasing in coverage at at this hour. Bases are around 1500 ft MSL and tops are around 1800 ft MSL. CIG impacts currently at KSAN and KCRQ likely at KSNA around 06Z. Bases could go lower overnight but will likely remain at or abv 1000 ft MSL. Low clouds will likely spread up to 20 miles inland by 13Z, obscuring higher terrain with VIS restrictions where clouds and terrain intersect. CIGs and reduced VIS could impact KONT after 10Z but confidence is low. CIG and VIS impacts not likely at KSBD. Expect inland clearing 15Z-18Z and clearing at the coast 18Z-20Z. Mountains/Deserts...SKC with unrestricted VIS. && .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...Heat Advisory from noon to 8 PM PDT Saturday for San Bernardino and Riverside County Valleys-The Inland Empire. Excessive Heat Warning from 10 AM Friday to 8 PM PDT Saturday for Coachella Valley-San Diego County Deserts-San Gorgonio Pass Near Banning. PZ...None. && $$ PUBLIC...EA/CO AVIATION/MARINE...PG