671 FXUS66 KSGX 071532 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 832 AM PDT Sat Jun 7 2025 .SYNOPSIS... A deep marine layer with patchy drizzle persists this morning, then a shallower marine layer Sunday through much of next week. Temperatures warm through the weekend, peaking Monday and Tuesday, before a slow cooldown into the end of next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .UPDATE... No major changes from the previous forecast. Drizzle did transpire this morning with some accumulations recorded up to 0.04" across San Diego County valleys and coastal areas. Similar to Friday, clouds will slowly recede from the inland areas through the afternoon, but are likely to remain socked in for coastal regions. Drier and warmer conditions along with a shallower marine layer return Sunday and prevail through mid week before cooler weather returns Thursday/Friday. .PREVIOUS DISCUSSION FROM 240 AM... Marine layer low clouds continue to fill in west of the mountains this morning. Drizzle has been occurring, most widespread over San Diego County where some valley locations have managed to pick up measurable precipitation. Low clouds will be slowly clear inland later this morning, but coastal areas will likely remain cloudy through the day. We remain wedged between a closed low off the Central CA coast and a building upper level high over northern Mexico today, which will slowly expand northwestward into Sunday. This will bring warming inland where highs will be around 3-5 degrees above normal today and around 5-8 degrees above normal on Sunday. The marine layer remains sufficiently deep with continued onshore flow to moderate temperatures west of the mountains where highs will remain closer to normal. The closed upper low becomes an open wave and moves by to the north as the upper ridge amplifies to our west, bringing continued warming Monday and Tuesday. The marine layer becomes more shallow with low clouds and patchy fog confined to the coastal areas and far western valleys each night and morning, though clearing at the beaches will still be somewhat limited. In terms of temperatures, by Tuesday there is a 15-25% chance of high temperatures of 100 degrees or more in the far inland portions of the Inland Empire and a 40-60% chance in parts of the high desert. For the low deserts, there is a 15-40% chance of high temperatures of 110 or higher. The ridge begins to flatten in response to a weak short wave moving by to the north on Wednesday, resulting in minor cooling. A second wave begins to drop south on Thursday, then a long wave trough amplifies along the West Coast Friday into next weekend. This will bring more significant cooling, breezy conditions in the mountains and deserts, and a deeper marine layer with low clouds extending into the inland valleys once again. && .AVIATION... 071530Z....Coast/Valleys...BKN-OVC low clouds with bases 800-1800 ft MSL, locally down to 300-500 ft MSL, have filled in the coastal basin. Local vis restrictions of 3-5 SM are being observed. Clouds and vis restrictions will clear from the Inland Empire through 18Z and from Orange County and San Diego valleys 17-19Z. Cigs likely remaining with in 15 miles of the San Diego County coast through the day. Low clouds begin to push inland again after 00z Sun and should fill in the coastal basin by 10Z Sun. BKN-OVC bases will be 600-1200 ft MSL with vis reductions 3-5 SM in the valleys and near higher coastal terrain. Mountains/Deserts...Mostly clear skies and unrestricted vis through tonight. && .MARINE... No hazardous marine conditions are expected through Wednesday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...Zuber AVIATION/MARINE...CO