Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
316 FXUS66 KSGX 151609 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 909 AM PDT Sat Jun 15 2024 .SYNOPSIS... High pressure aloft will bring another hot day to the valleys and deserts today. Sunday and Monday will not be quite as hot as a trough of low pressure moves inland across California. Hot weather will return next weekend as another ridge of high pressure builds over the desert Southwest. Night and morning low clouds will continue along the coast, spreading into the western valleys Monday and Tuesday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .Morning Update... Low clouds filtered into the coastal valleys this morning, where some areas saw some dense fog. The clouds are clearing back toward the coast this morning, with some beaches becoming sunny in San Diego County. Most areas should at least partially clear by the afternoon as the inversion slowly mixes out. Today will be the hottest day over the next week for many with highs reaching the triple digits for eastern parts of the Inland Empire into the deserts. Make sure to take break if spending time outdoors today and don`t forget that water bottle! There is a moderate to high chance temperatures will be over 110 degrees today across the lower deserts and over 100 degrees across the high deserts and the eastern IE. Onshore flow kicks in more on Sunday, knocking temperatures down 5 to 10 degrees for inland areas and breezy conditions across mountains and deserts. A troughing pattern is likely to prevail for much of the upcoming work week, leading to increasing clouds west of the mountains and cooler weather overall across the region. Warmer weather is expected by the end of the week. .Previous Discussion... Friday`s high temperature of 115 at Palm Springs and Ocotillo Wells Friday was one degree shy of the nation`s high of 116 at Death Valley. Today will be just as hot as yesterday with highs from 112- 116 in the Lower Deserts where an Excessive Heat Warning is in effect through 8 PM today. The record high of 113 at Borrego Springs is within reach. A ridge aloft has suppressed the marine layer depth and that will also bring this hot airmass to some of the valleys. The most impacted areas will be the eastern sections of the Inland Empire where highs will be 95-100 at San Bernardino, Beaumont, Hemet, and Perris. A Heat Advisory is in effect from these areas through 8 PM today. A shallow marine layer has kept most of the low clouds confined to the coastal zones, most of which will clear from the beaches this afternoon. The ridge moves east tonight and will be replaced by a Pacific trough over the West that will bring cooler weather Sunday through Tuesday. The trough, combined with a developing coastal eddy, will deepen the marine layer Monday and Tuesday, deep enough for low clouds to spread back into the valleys. This trough will also bring gusty west winds to the mountains and deserts each late afternoon and evening. On Wednesday and Thursday the trough weakens and lifts north, replaced by a new ridge building over the desert Southwest for gradual warming midweek. The heat grows Friday through Sunday as the ridge strengthens to a 592 dm high over Arizona and New Mexico. This weather pattern will bring hot weather back to the deserts next weekend when highs will be 110-115 in the lower deserts, 100-105 in the high deserts, and from 95-100 in the eastern sections of the Inland Empire. A shallow marine layer will moderate temperatures near coast where highs will be in the 70s to low 80s. && .AVIATION... 151600Z...Coast/Valleys...Mostly clear skies will prevail with mostly unrestricted VIS through this evening, except for patchy BKN stratus at the beaches with bases 600-1000 ft MSL. Stratus will be delayed tonight but spread up to 20 miles inland after 07Z Sun with bases 700-1100 ft MSL and tops to 1300 ft MSL with an increasing trend in cloud base height, especially after 14Z Sun. Local VIS 1-3 miles in BR will occur 08Z-15Z Sun mainly in the coastal valleys. Stratus will clear much slower Sun and might not clear at all near the coast. Mountains/Deserts...SKC with unrestricted VIS will continue through Sun morning. Areas of wind gusts 25-35 kt from the west will occur on the desert mountain slopes and into the deserts from 21Z today through Sun, along with weak to MOD UDDFS. PSP could have gusts to 25 kt from 23Z today through 04Z Sun. && .MARINE... Northwest winds may gust to around 20 knots at times in the outer waters near San Clemente Island each afternoon and evening through Monday. Otherwise, no hazardous marine conditions are expected through Thursday. && .BEACHES... A combination of a west swell of around 6 feet/10 seconds (outer waters) and south swells of around 2 feet/14 seconds becoming 18 seconds Monday will bring surf of 3-6 feet along with a high rip current risk. The surf and rip current risk will gradually lower around Tuesday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement through Monday evening for Orange County Coastal Areas-San Diego County Coastal Areas. Heat Advisory from noon today to 8 PM PDT this evening for San Bernardino and Riverside County Valleys-The Inland Empire. Excessive Heat Warning until 8 PM PDT this evening for Coachella Valley-San Diego County Deserts-San Gorgonio Pass Near Banning. PZ...None. && $$ PUBLIC...APR/Moede AVIATION/MARINE...Maxwell