Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
165 FXUS66 KSGX 022053 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 153 PM PDT Tue Jul 2 2024 .SYNOPSIS... A long-duration heat wave will continue inland through at least the weekend. Friday and Saturday are expected to be the hottest days for most areas with the only relief from the heat toward the coast. The marine layer will slow the warming near the coast with night and morning coastal low clouds spreading into the western valleys late each night. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Under full sunshine, temperatures near the coast are running a little higher than yesterday at this time. It will only get warmer in coming days and the inland heat warrants most of our attention for the coming week. A strong upper ridge develops Wednesday just off the coast and spills into CA and the West through Saturday. And I do mean strong; a lot of guidance shows heights that reach 600 decameters over NorCal Thursday through Saturday. Friday and Saturday right now appear the be the hottest days. Heat warnings are in effect in all desert regions through next Tuesday. Heat Warnings are in effect for mountains and inland valleys Friday and Saturday. And Heat Advisories are in effect for inland Orange County and the Santa Ana Mountains Friday and Saturday. This heat wave will be significant and long-lasting even for early July. Temps at night will not cool off much, so the accumulated heat risk will add to the stress on humans. The marine layer will get more shallow for the rest of the week, with less nocturnal coverage, but coastal clouds and fog will not go away entirely. Max temps today through Thursday will range from 2 to 12 degrees above normal, with the greatest anomalies in the desert. On Friday and Saturday, the hottest days, max temps will range from 6 to 15 degrees above normal. That puts Palm Springs up to 122, flirting with the highest temps on record. The 12Z model/ensemble guidance has a slightly better consensus on the ridge beginning to weaken Sunday, but only slightly. Enjoy the barely noticeable drop in temperatures of a few degrees. && .AVIATION... 022000Z...Coast/Valleys...Marine layer low clouds have pulled offshore 20-25 SM and mostly clear skies and unrestricted VIS will continue through this afternoon. Low clouds with slightly lower bases 600-1200 ft MSL return vcnty coastal sites 02-06Z this evening. Vis of 3-5 SM in mist expected 09-16Z Wed over higher coastal terrain and in coastal valleys, locally down to 1 SM. Low clouds clearing to the coast again 15-18Z Wed. Mountains/Deserts...Mostly clear skies with unrestricted VIS will continue through tonight. West winds will return to the desert slopes and through San Gorgonio Pass this afternoon/evening but will be generally weaker, with most gusts 25 kt or less. Similar winds Wed afternoon/evening and FEW to SCT clouds at or above 10,000 ft MSL forming over ridgelines. && .MARINE... No hazardous marine conditions are expected through Sunday. && .BEACHES... A swell of 2-3 feet from 190 degrees with a period of 16-18 seconds will arrive at SoCal beaches as early as Wednesday morning, peak Friday and gradually subside next Sunday into Monday. This will lead to elevated surf with breaking wave heights up to 7 feet, mainly on exposed south and southwest-facing beaches in Orange County. Rip and longshore current risks will be high the second half of this week. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement from Thursday morning through Sunday afternoon for Orange County Coastal Areas-San Diego County Coastal Areas. Excessive Heat Warning from 11 AM Friday to 9 PM PDT Saturday for Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys. Heat Advisory from 11 AM Friday to 9 PM PDT Saturday for Orange County Inland Areas-Santa Ana Mountains and Foothills. Excessive Heat Warning until 9 PM PDT Tuesday for Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts- San Gorgonio Pass Near Banning. PZ...None. && $$ PUBLIC...MM AVIATION/MARINE/BEACHES...CSP