739 FXUS66 KSGX 262011 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 111 PM PDT Sat Jul 26 2025 .SYNOPSIS... A trough across the West Coast will continue cooler than normal weather through the weekend. High pressure will expand further west, bringing in a warming trend by Sunday into Tuesday, with temperatures staying near average through the end of next week. Breezy west winds will continue this weekend across mountains and deserts, while the marine layer provides low clouds at times west of the mountains. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... A trough currently draped over the West Coast continues to provide onshore flow and cooling across our region. The calendar may say late July but temperatures across the area are more like that of late May or early June. Widespread 70s and 80s are seen for areas along and west of the mountains with highs nearing 100 degrees in the lower deserts this afternoon. This troughing pattern will dominate through the weekend with below average temperatures and deep marine layer, leading to much of coastal basin to see low clouds tonight into Sunday morning. An area of high pressure across the Southern Plains will begin to expand closer to our region, where heights will rise. This will bring a more noticeable warming trend by Monday and Tuesday, where temperatures will climb to seasonal averages. There is high confidence that temperatures will go closer to 110 degrees across the lower deserts and 90s for the IE and high desert. Confidence lowers by the end of the week as the exact placement of the high pressure system will determine how warm we become. For now, NBM continues to be used to describe the latest thinking with temperatures plateauing Tuesday into later next week. If the area of high pressure expands further west, temperatures may need to be increased a few degrees. Whatever occurs, moderate heat risk will return to the lower deserts during this time period. It is summer indeed, but make sure to take breaks if you must be outdoors! && .AVIATION... 262000Z....Coasts/Valleys...Mostly clear skies and VFR conditions prevail through late this afternoon until low clouds based 2000-2500 ft MSL redevelop this evening after 27/01Z. Clouds will spread first into San Diego County when they develop, but will move northward into Orange County by 09Z then into the Inland Empire by 12Z. Clouds clear inland 27/15-17Z and for the coast 16-18Z. Mountains/Deserts...Mostly clear with VFR conditions through Sunday. && .MARINE... No hazardous marine conditions are expected through Thursday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...APR AVIATION/MARINE...CSP