635 FXUS66 KSGX 291800 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 1100 AM PDT Mon Jun 29 2026 .SYNOPSIS... Increased winds over the mountains and deserts this afternoon into Tuesday morning. 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 early next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... The overall pattern will remain troughy through Friday, with another shortwave expected to move through the mean flow tomorrow. This will increase the onshore pressure gradient, maintaining a deeper marine layer, elevating winds, and maintaining below average temperatures. Additionally, patchy drizzle is possible tonight into Tuesday morning. Peak winds for the mountains, deserts, and passes this afternoon into Tuesday morning will be 35 to 50 mph. Gusts up to 60 mph possible through San Gorgonio Pass. Conditions will gradually warm each day through the holiday weekend, but highs through Wednesday for inland areas will be 10 to 20 degrees below average. For the 4th of July there is more confidence in weak ridging developing over the US West Coast, with more uncertainty in the strength and placement of the ridge into early next week. Even with ridging aloft this weekend, highs in and west of the mountains will be 1 to 5 degrees below average, with highs in the deserts up to 3 degrees above average. The marine layer will stay deep through mid-week becoming shallower and more confined to the coast and western valleys for Friday into early next week. && .AVIATION... 291745Z....Coast/Valleys/Foothills...Low clouds based 2500-3500 ft MSL are lingering late this morning over northern portions of the coastal basin (including KONT, KSBD, KSNA). Clouds should scatter to the coast in the next few hours with SKC for a few hours this afternoon. Low clouds with similar bases return to coastal areas starting 01-03z, completely filling the coastal basin once again by 08-10z. Patchy -DZ expected with greatest chances near the coastline. Local minor cig/vis reductions (1500-2000 ft MSL and 4- 6SM) with -DZ. Clouds scatter back toward the coastline 16-19z Tue. .Mountains/Deserts...Winds re-strengthen this afternoon after 22Z, with gusts 20-40 kts along desert slopes and locally into deserts. Gusts to 55 kts through the Banning Pass. Winds slowly weaken again 06-12z Tue. && .MARINE... No hazardous marine conditions are expected through Saturday. && .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...CO AVIATION/MARINE...KW