899 FXUS66 KSGX 290536 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 1036 PM PDT Sun Jun 28 2026 .SYNOPSIS... Increased winds over the mountains and deserts at times through Tuesday. A deep marine layer and well below average conditions will prevail through the middle of the week. A gradual warming is expected into the 4th of July holiday weekend, with conditions warming to near or slightly above normal by next Sunday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... ...Updated Aviation Discussion Below... There were a few drizzle reports last night and this morning, mainly focused in coastal areas of northern San Diego County. The marine layer deepened about 2300 ft from yesterday as the main core of the trough of low pressure moved into the Great Basin. The overall pattern will remain troughy through Friday, with another shortwave expected to move through the mean flow early Tuesday. This will increase the onshore pressure gradient again, maintaining a deeper marine layer, elevating winds, and maintaining below average temperatures. Additionally, patchy drizzle is possible Monday night into Tuesday morning. Winds over the mountains and into the deserts will remain elevated today, but weaker than yesterday. Peak wind gusts yesterday topped out at 72 mph at Cuyamaca Peak, 69 mph at White Water, and 56 mph at Burns Canyon. Strongest winds today will be through the San Gorgonio Pass and in the San Diego deserts with peak gusts 45 to 55 mph, with local gusts to 65 mph through the pass. Winds will weaken into Monday morning. Winds for the mountains, deserts, and passes on Monday evening into Tuesday look like they will likely peak at 35 to 50 mph. Strongest winds will be through west to east oriented passes, like the San Gorgonio Pass. Highs through Wednesday for inland areas will be 10 to 20 degrees below average. There is good model agreement in the upper level pattern through next Friday. For the 4th of July weekend, there is more uncertainty in the upper level pattern. About half of the ensemble solutions indicate ridging will develop over the western United States although there are varying solutions as to where. 20 to 30 percent of ensemble solutions have the ridge in a position to bring us more notable warming. Official forecast follows the NBM for the end of the week which indicates a gradual warming trend Thursday through the weekend. By next Sunday some locations will start to see near or slightly above average temperatures. && .AVIATION... 290530Z....Coast/Valleys/Foothills...Low clouds based 2000-3000 ft MSL are developing into the inland valleys and into Orange County. Slow expansion of clouds to continue through 10z, covering most of the coastal basin. Small chance (10%) for -DZ/BR along coastal slopes. Vis 0-5SM along foothill terrain. Clouds scatter out 15-18Z Mon. Patchy low clouds at the coast become BKN-OVC beginning around 00- 02Z Tue, then expand into inland areas. While the main cloud base is expected to be around 2500-3500 ft MSL, there may be FEW-BKN cloud layers down to 1500 ft MSL, as well as patchy -DZ/BR. .Mountains/Deserts...West winds gusting 25-45 kt on the desert slopes with local gusts to 55 kt through the San Gorgonio pass diminish overnight into early Mon. MOD up/downdrafts in lee of mountains and pockets of BLDU. Winds re-strengthen Monday after 22Z, with similar gusts as this evening. && .MARINE... No hazardous marine conditions are expected through Friday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory until 11 PM PDT this evening for San Diego County Deserts. Wind Advisory until 2 AM PDT Monday for San Gorgonio Pass near Banning. PZ...None. && $$ PUBLIC...CO AVIATION/MARINE...Westerink