Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
069 FXUS66 KSGX 290353 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 853 PM PDT Sat Jun 28 2025 .SYNOPSIS... High temperatures will warm a few to around 5 degrees this weekend with high temperatures within a few degrees of average to around 5 degrees above average. High temperatures will then cool about 5 degrees through the middle part of next week with high temperatures on Thursday around average to around 5 degrees below average for the valleys. The marine layer lowers some this weekend, but lifts again early next week, with night and morning coastal low clouds spreading into the western valleys, clearing by the mid-late mornings. .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .Evening Update... Low clouds will continue to develop in the marine layer later this evening. Areas of fog and reduced visibilities expected in the early morning hours of Sunday for inland valleys and inland Orange County. Sunday will feature high temperatures similar to today throughout the coastal basin and are expected to increase a degree or two in the deserts. Despite the relatively thin marine layer, the afternoon onshore breeze Sunday will be robust for mountain passes and desert communities. .Previous Discussion (152 PM Saturday)... A warm and dry weekend is on tap as the subtropical ridge axis stretches over southern California. This is resulting in temperatures across the inland valleys reaching the upper 80s to low 90s in the San Diego county valleys and the mid to upper 90s for the Inland Empire, while the deserts see highs 105-110. While these temperatures are only about 5 degrees above average for the inland valleys, today/Sunday will still feature the hottest temperatures of the week as the ridge retreats eastward. A fairly stagnant upper level pattern is then established late Sunday with the ridge now in place across the Four Corners and a cut-off low centered about 200- 300 miles off the coast of California. This pattern persists through mid-week when the trough slides eastward over California on Wednesday into Thursday. Through this stagnant pattern, the deserts stay hot Monday into Tuesday while the inland valleys are a little cooler. Still, the deserts very slowly cool Monday through Wednesday. The pattern begins to grow more uncertainty Thursday through the end of the week. Within this uncertainty, what appears more certain is the increase in monsoonal activity, although staying east of SoCal. && .AVIATION... 290345Z....Coast/Valleys...Low clouds based 600-1000 ft MSL continue to increase in coverage near the San Diego coast. Low clouds will expand over the beaches and push inland up to 5-10 miles after 05Z, impacting VCTY KSNA by 09-10Z Mon. Vis of 1-4SM for western valleys and higher coastal terrain, locally below 1SM 11-14z Sun. Clearing to the coast 15-17Z. .Mountains/Deserts...SW/W wind gusts 25-35 kts across the deserts and mountain passes Sunday afternoon 20Z-05Z Mon leading to MOD UDDFS at times. Winds weaken again by overnight Sunday. && .MARINE... No hazardous marine conditions are expected through Wednesday. && .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...Westerink/Munyan AVIATION/MARINE...APR