FXUS66 KSGX 091813 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 1000 AM PST Fri Feb 9 2024 .SYNOPSIS... Scattered showers will continue from the coast to the mountains today, decreasing tonight and ending by early Saturday. Dry weather will prevail with a slow warming trend this weekend and most of next week. with high temperatures warming to near average for the middle of next week. The flow will turn briefly offshore with gusty north winds to 35 to 45 mph Saturday morning along and below the coastal slopes of the San Bernardino County mountains. A wetter pattern may return the weekend of February 17-18. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Scattered showers continued at mid-morning with greatest areal coverage in San Diego County and far southern Orange County. Hourly rainfall rates have been less than 0.10". Otherwise, mostly cloudy skies continued from the mountains west to the coast, with partly cloudy conditions in the deserts. It will be another chilly day with highs mostly in the mid 50s to lower 60s at lower elevations. One last wave will dive south tonight on the west side of the deep western US trough to keep the scattered showers going overnight, especially San Diego County, though HREF does show some activity in the San Bernardino Mountains too with hourly probabilities of measurable precip reaching 60% at 3 AM there. The high pressure ridge off the West Coast will move into the Western US, though with occasional shortwaves moving through to moderate the strength of the ridge. Thus, the temperature increase will be gradual, though with temperatures probably just making it to near normal by mid-week, even though some MOS values, including from the ensemble ENS, have above normal temperatures inland the second half of next week. Low temperatures could be a concern Saturday and Sunday nights in the valleys with guidance suggesting temperatures near or slightly below freezing in coldest locations. NBM has about a 50-60 percent chance of temperatures at 4 AM Sunday at/below 32 in from Temecula to Perris that typically gets cold during clear calm winter nights. A frost advisory will likely be needed Saturday and Sunday nights in the valleys, though San Diego County's risk area is smaller, mostly near Ramona and the San Pasqual Valley. Also, some north/northeast winds will occur mainly in San Bernardino County Saturday morning, but high-resolution models indicate gusts remaining below 45 MPH in windiest locations, with winds dropping Saturday afternoon. Ensemble solutions show a deep trough next weekend (17-18 Feb) off the coast, with some variability in the timing/distance from the coast. We will likely receive at least some precipitation, and some ensembles indicate 70+ 24-hour probabilities of measurable precip and even a 30+ 24-hour probability of exceeding 1 inch in some areas from the mountains west to the coast, with hints of an atmospheric river. && .AVIATION... 091630Z...Coast/Valleys...BKN clouds based between 2500-5500 feet MSL and layered to 8000 feet with SHRA with lower CIGS briefly down to 1500 feet MSL and VIS briefly 2-5SM in +SHRA through 21Z. SCT-BKN clouds 3000-6000 feet MSL with ISO SHRA especially in San Diego County after 21Z. Scatter out and clear out from north (KONT) around 07Z tonight to south (KSAN) by 16Z. Mountains...Multiple cloud layers to 10000 feet MSL and SHRA/SHSN obscuring the mtns through the evening. Scattering out 06-12Z. Northeast winds developing after 10Z tonight and strengthening Saturday morning. Local MOD up/downdrafts and pockets of LLWS in lee of San Bernardino Mountains after 17Z Saturday. Deserts...SCT locally BKN clouds based 4000-7000 feet MSL today and tonight through 12Z. SKC after 15Z Saturday. && .MARINE... Northwest winds occasionally gusting over 20 knots over the outer waters tonight. Otherwise, no hazardous marine conditions are expected through Tuesday. && .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...Maxwell AVIATION/MARINE...MM