347 FXUS66 KSGX 081133 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 433 AM PDT Fri Oct 8 2021 .SYNOPSIS... A low pressure system moving inland through the area today will bring cooling, stronger and gusty southwest to west winds in the mountains and deserts, and rain in the morning with decreasing showers in the afternoon. Dry with a warming trend for the weekend with Sunday the warmest day for the next week. A low pressure system from the northwest will bring cooling for early next week with strong and gusty west to northwest winds in the mountains and deserts and with a slight chance of showers for the mountains for late Monday and Monday night. Winds will turn north to northeast and weaken for Tuesday into Wednesday with a warming trend for the middle and latter part of next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Sunday)... Little has changed with the forecast through the weekend. A low pressure system is moving inland through southern California today and will begin to move east on Saturday with high pressure aloft from the northwest on Sunday. Light rain continues to spread inland across the area. It is expected to decrease after mid morning with some showers lingering for inland areas through the afternoon. The greater rain amounts are expected in San Diego County ranging from around one-third inch near the coast to one-half to one inch in the mountains. Amounts from the coast to the mountains will be a little less to the north of San Diego County with mostly one-tenth inch or less in the deserts. Hourly rainfall rates will mostly be 0.15 inch or less. Dry weather will return tonight. Today will be cooler and the coolest day this week with high temperatures in the mountains 20 to 25 degrees below average. Highs for the coast, valleys, and high desert will be mostly in the 60s, mostly in the 70s in the lower deserts, 50s in the mountains below 6000 feet and 40s above 6000 feet. The weekend will be dry and warmer. Saturday will be around 5 degrees warmer to locally 10 degrees warmer in the mountains than today. Warming will continue on Sunday with high pressure aloft and weak offshore lower level flow. Sunday is expected to be the warmest day for the next week but with high temperatures for inland areas still a few to around 5 degrees below average. Enough warming will occur for coastal areas to be around 5 degrees above average. && .LONG TERM (Monday through Thursday)... A cold low pressure system from the northwest will move into the western states on Monday, then begin to move east on Tuesday. There remain differences among the global models with the amplitude of the system and with the speed of the eastward movement on Tuesday and Wednesday. The current forecast is close to the NBM with cooling for Monday and Tuesday and with warming for Wednesday and Thursday. Tuesday night would be the coolest night. Patchy frost remains a possibility for portions of the high desert for late Tuesday night and early Wednesday. The NBM probability of temperatures at Victorville reaching 35 or lower early Wednesday has increased to 70 percent. That system for Monday and Tuesday will also bring periods of strong gusty west to northwest winds on Monday and Monday night with the winds becoming northeasterly and weakening for Tuesday into Wednesday. There is a slight chance of showers, mainly for the mountains, for late Monday and Monday night with some snow possible in the higher elevations in mountains for Monday night as snow levels lower. A system a little farther west and more amplified would have greater precipitation potential with less chance for precipitation for a system less amplified and not as far west. && .AVIATION... 080900Z...Coast/Valleys...BKN-OVC low clouds will continue to spread inland this morning, covering much of the coastal basin by 12Z. Bases will be 1500-2500 feet MSL, with cloud layers up to 20,000 feet MSL. SHRA will continue to move west to east this morning, with the most widespread precipitation expected 12-18Z. Vis restrictions to 2-4 miles in BR in areas of SHRA. SHRA will end west to east after 18Z. Higher terrain obscured through this afternoon. Mountains/Deserts...SCT-BKN clouds at/above 8,000 feet MSL through today. West winds gusting 25-40 kt at times through the passes and along the desert slopes through this evening. Periods of SHRA expected through 22Z. Vis restrictions to 2-4 miles in SHRA and fog in the mountains. && .MARINE... Northwest winds occasionally gusting around 20 kt likely this afternoon and again Saturday afternoon in the outer waters. Stronger northwest winds likely next Monday-Tuesday, with gusts around 25 kt. && .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...17 AVIATION/MARINE...Connolly