Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
450 FXUS66 KSGX 150927 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 230 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... 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... 150900Z...Coast/Valleys...Low clouds slowly but steadily moving farther inland with bases around 600-1000 FT MSL. Low clouds will eventually spread 10 to 15 miles inland by about 13-14z, with a 40% chance of MVFR VIS at the coastal TAF sites as well. Areas of fog with VIS 1-3SM expected on higher coastal terrain. Clearing to the beaches looks to occur 14-16z. Low clouds will be slow to redevelop again Saturday evening, likely some time around or shortly after 06z Sun. Bases again would start low, most likely below 1000 FT MSL before rising due to the development of a coastal eddy. Mountains/Deserts...SKC with unrestricted VIS through Saturday. W-NW winds gusting 20-25 knots expected around KPSP through this evening. Weak to MOD UDDFS expected over and east of the mountains. && .MARINE... Northwest winds may gust to around 20 knots at times in the outer waters near San Clemente Island each afternoon and evening Saturday through Monday. Otherwise, no hazardous marine conditions expected. && .BEACHES... Long period south swells will bring surf of up to 6 feet at times along with increased rip current risk through Monday. && .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...Moede AVIATION/MARINE/BEACHES...Adams