953 FXUS66 KSGX 231632 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 832 AM PST Sun Feb 23 2020 .SYNOPSIS... Cloudiness and isolated showers will continue this morning from the coast to the mountains before conditions clear during the afternoon. An upper level ridge will build in from the west this week, resulting in dry and warmer weather. Locally gusty northeast to east winds will occur below passes and canyons Monday through Friday, with the strongest winds Tuesday and Wednesday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Some very light showers were barely detectable on NWS radar this morning, but remote rain gages still indicated some 2-hr 0.01-0.04" amounts through 8 AM PST, mainly near the coastal foothills. Based on the latest hires model runs, this should end by Noon, if not sooner. Thick marine clouds were still backed up against the coastal mtn slopes but many areas west of the mts were clearing, at least partially. The 12Z Miramar sounding had a nearly saturated layer from the sfc to 5500 FT MSL. No significant inversion was present. Based on the radar and hires model trends, the forecast looks to be on track. Given the deep moist layer though, some areas will see only limited sun today west of the mts. It will be noticeably warmer with more sun after the morning burn-off west of the mountains. From previous discussion... The weather pattern this week will feature a building ridge from the west with the upper ridge axis overhead by Thursday. This will mean dry weather conditions this week along with warming temperatures with temps by midweek well into the 70s most areas and even into the 80s over the inland valleys and lower deserts. Offshore winds will predominate much of the week and be strongest Monday and Tuesday morning, but with gusts through and below passes and canyons only looking to be at about 40 mph or so, so not too strong. An upper level trough will start to develop over the West Coast next weekend as a shortwave dives into the Pacific Northwest. This will lead to slight cooling over the area as we close out the week. As the shortwave dives southeast, a return of showers could arrive as early as Sunday, March 1st. The first week of March looks to be cooler with at least a chance of some precipitation. && .AVIATION... 231600Z...Coast/Valleys...Isolated -SHRA ending by 18Z. Multiple stratus layers with bases 2000-4000 ft MSL and tops to 5500 ft MSL gradually becoming SCT to locally BKN this afternoon with bases mostly above 3000 ft MSL. Low clouds redeveloping after 24/04Z with bases near 1500-2000 ft MSL. Local vis 3-5 SM or less in BR/FG possible in the valleys 24/09-24/15Z. CIGS clearing by 19Z Monday. Mountains/Deserts...Isolated -SHRA ending by 18Z. Coastal mountain slopes remaining partially obscured in clouds/fog through this evening. Then mostly clear with unrestricted vis tonight into Monday morning. && .MARINE... No hazardous marine weather is expected through Thursday. && .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...10/Gregoria AVIATION/MARINE...SS |