Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
924 FXUS66 KSGX 102044 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 144 PM PDT Thu Jul 10 2025 .SYNOPSIS... Hot inland and cool at the coast for the rest of today. Friday will cool a little, with minor day to day changes through the middle of next week. A deepening marine layer will bring more coastal clouds extending farther inland during the nights and mornings. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Temperatures were running very similar to those yesterday as of midday, some a little higher and others a little lower. Deserts are a little cooler, while many inland valleys are a little warmer. Areas of low clouds are sticking to the beaches in San Diego County. Temperatures today show a great contrast from the temperate coast to the scorching desert. The midday temp was 67 at Oceanside Harbor and 114 in Ocotillo Wells. While it doesn`t appear desert temps will reach those record levels of yesterday, extreme heat warnings are warranted and still in place for the lower deserts through sunset. In the valleys, highs will be in the 90s to about 106 and a heat advisory is out today, particularly for the more inland valleys where a few temps in spots already exceed 100. These inland highs represent 6 to 12 degrees above normal today. A Heat Advisory remains in effect through sunset. A temporary but strong ridge overhead has brought our region the kind of subsidence and compressional heating needed for this heat episode. This should be the final day of extreme heat. This high will weaken slightly Friday, and some additional gulf moisture creeps into the lower deserts, allowing for a drop of several degrees, but still up to 8 degrees above normal in the low desert for mid July. Valleys will trend close to normal for the weekend. The marine layer will get a boost by a coastal eddy tonight and Friday to rebuild and extend low clouds and fog into western valleys and for a longer time each night and morning. For next week, minor variations in the upper high will maintain this rather seasonal weather, except slightly hotter than average in the deserts. There are hints of monsoon moisture increasing next Wednesday through Friday for an extremely slight (but nonzero) chance of showers and thunderstorms across the southern interior. We`ll need more consistency and consensus in ensemble solutions that far out to add precip to the forecast. && .AVIATION... 102045Z....Coast/Valleys...Low clouds (based ~1000-1400ft MSL) have stuck around along the south-central San Diego County beaches this afternoon. Otherwise, clear skies and VFR conditions prevail through the day. Aided by a coastal eddy tonight, low clouds fill back in and push ashore tonight with slightly higher bases and more inland extent. 70% chance for CIGs at KSAN by 06z with KCRQ likely closer to 09z. Clouds may reach KSNA around 10-14z, but there is about a 40- 50% chance of this. Bases will be closer to 1000-1500ft MSL with about 10-15 miles of inland extent. Scattering back to the beaches by 16-17z Friday. Mountains/Deserts...VFR conditions and unrestricted VIS through Friday afternoon. && .MARINE... No hazardous marine conditions expected through Monday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 8 PM PDT this evening for Riverside County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys. Extreme Heat Warning until 8 PM PDT this evening for Coachella Valley-San Diego County Deserts-San Gorgonio Pass near Banning. PZ...None. && $$ PUBLIC...MM AVIATION/MARINE...Munyan