887 FXUS66 KSGX 072136 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 136 PM PST Sun Nov 7 2021 .SYNOPSIS... A developing trough along the West Coast will keep the weather cool west of the mountains, with night and morning low clouds and patchy fog through Tuesday. Some drizzle is possible again early Wednesday morning, otherwise, dry weather will prevail. Winds will turn offshore during the latter half of the week, with Santa Ana conditions beginning on Thursday. Friday should be the warmest day overall, with temperatures some ten to fifteen degrees above average across the coast and valleys. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... -Forecast Highlights- * Tranquil with little day to day changes through Tuesday * Santa Ana Winds late week/much warmer west of the mountains The weather pattern through Tuesday will be rather stagnant with little noticeable changes from day to day. It will remain slightly cooler than normal west of the mountains as onshore flow continues due to an upper level trough moving into the state. Rain associated with this feature will impact NorCal, but here in SoCal, just patchy drizzle at most is forecast by Wednesday morning. Otherwise, it will continue dry with west winds prevailing. The upper trough will shift east on Wednesday with surface high pressure building into the Great Basin. This will lead to the development of Santa Ana Winds by Wednesday afternoon, strengthening Wednesday night-Thursday morning, then will subside through Friday. Weak to locally moderate strength is forecast with gusts up to 40 mph immediately below the Cajon Pass and below wind-favored canyons along the coastal slopes of the mountains. Temperatures will be on the rise beginning on Wednesday, but a noticeable jump in temps will occur on Thursday where high will reach into the 80s for the coast and valleys. The warmth will peak on Friday as an upper ridge builds in from the southwest. There is even a shot at temps around 90 degrees over parts of the inland valleys and inland Orange County. Also, the lower deserts will heat up to around 90 both Friday and Saturday. Kept the forecast trend of going slightly warmer than NBM for the late week period as typically the warmer guidance is favored in this Santa Ana wind regime along with a building upper ridge. The weather pattern into the 3rd week of November favors drier and warmer than normal conditions continuing as the storm track stays off to the north. && .FIRE WEATHER... Onshore flow will continue before offshore flow takes over beginning Wednesday afternoon. The Santa Ana Winds will be strongest late Wednesday night-Thursday morning with northeast wind gusts 20-30 mph, locally to 40 mph below the Cajon Pass and favored canyons and coastal slopes of the Santa Ana and San Diego County mountains. Winds will weaken slightly Thursday afternoon- Friday and weaken more significantly Friday afternoon. Relative humidity will fall to 15-20% inland each afternoon Thursday through the weekend with poor recovery Thursday night in wind prone areas. && .AVIATION... 072105Z...Coast/Valleys...Low clouds with bases 800-1400 feet MSL with tops to near 2200 feet MSL out over the coastal waters otherwise mostly clear. The low clouds will begin to move onshore and inland after 02Z. Vis reduced to 1-3 miles in HZ/FG in the valleys after about midnight. High confidence on BKN-OVC low clouds returning this evening at KSAN, and moderate-high confidence in timing in the KSAN TAF. Mountains and Deserts...SCT high clouds at/above 20,000 feet MSL and unrestricted vis expected through tonight. && .MARINE... No hazardous marine weather is expected through Thursday. && .SKYWARN... Skywarn activation is not requested. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...Gregoria AVIATION/MARINE...Small