The final round of rain, snow, and gusty winds will be today, with the cold front and band of precipitation moving from northwest to southeast late this morning through early evening. There is a slight chance of thunderstorms with this band. Showers and winds will diminish overnight. Patchy frost and fog likely in the Inland Empire late tonight into Friday. Fair, dry and warmer weather is expected over the weekend, and could persist through much of next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Scattered showers continue mainly in western San Diego and Riverside Counties this morning. It will be cold today by SoCal standards, and all areas not in the lower desert will struggle to reach 60 today. We await and look northwest to the next organized band of rain/snow associated with our final wave, or cold front, this week. It will push through SoCal late this morning through early evening, and gradually end overnight. Strong southwest winds will precede the front, with gusts 35-45 mph at the coast and 45-65 mph in the mountains and deserts (a few higher gusts). Wind advisories are in place all over the region. Winds turn westerly by sunset and gradually diminish overnight. Rainfall and liquid-equivalent snowfall will amount to roughly 0.25-0.50 in the coastal basin, 0.50 to 1.50 in the mountains, and less than 0.25 inch in the deserts. Snowfall will begin to accumulate at the 4500 foot elevation, 1-8 inches from that elevation up to 7000 feet, with 8-12 inches on the highest peaks. The combination of wind and heavy snow will make driving this afternoon and evening in the mountains an unsafe adventure better left undone. There is also a slight chance of thunderstorms mainly in coastal areas and western valleys along with this band. That could produce very gusty, erratic winds and brief heavy rain that could lead to localized flooding. Showers end overnight as the winds diminish and skies begin to clear from north to south. The clearing in the Inland Empire should open the door to patchy frost as well as ground fog by sunrise Friday. Fair and dry, but cool weather starts Friday, with some variable high clouds. Weak offshore flow over the weekend will boost the drying and warming trend as high pressure aloft amplifies a little. Temperatures in the 60s Saturday will be followed by lots of 70s Sunday at lower elevations. A weak and stationary ridge appears to be taking shape over California next week. There is a meddling atmospheric river that previous guidance had shown to give us some rain around Tuesday and Wednesday. But the guidance over the last couple of days shows that AR to not quite reach SoCal. As such, our forecasts are trending drier for all of next week.
191000z, In the coastal basin, ISO -SHRA and FEW-BKN clouds based 3000-6000 ft MSL tonight.
Clouds begin to fill in and lower after 12-15Z Thu from the coast to the mtns ahead of a cold front, bringing a band of RA/+RA. The main precip band will move northwest to southeast through the coastal basin from 18Z Thu to 03Z Fri. Southwest winds increase ahead of the band, gusting 25-35 kts through the coastal basin, 35-45 kts widespread for the mtns and deserts, and 50-65 kts along desert slopes. A few hours of MVFR cigs/vis are expected for the coasts/valleys. Mtns shrouded in FG and snow (mainly above 5 kft MSL) through early Friday morning, reducing VIS to 0-2SM at times.
Generally VFR conditions expected in the wake of the main band outside of the mtns. Winds also turn westerly and weaken through the coastal basin in the evening, though remain strong in the mtns and deserts through early Friday morning, particularly in San Diego/Riverside Counties.
Overnight into early Fri, scattered SHRA activity is expected to continue throughout SD County overnight while cloud coverage begins to decrease over Orange County.
Strong southwest winds gusting to 30 knots and steep 8-11 feet seas will develop late this morning, producing hazardous conditions for small craft. Winds remain strong and turn northwesterly in the late afternoon, then weaken overnight into early Friday. Seas also diminish Friday morning.
This afternoon, high surf of 4 to 7 feet is expected with sets as high as 9 feet, highest in San Diego County. Surf diminishes Friday afternoon. Dangerous swimming and surfing conditions and localized beach erosion can be expected. A High Surf Advisory is in effect through Friday and contains more details.
Ca, High Surf Advisory until 10 PM PST Friday for Orange County Coastal Areas-San Diego County Coastal Areas.
Wind Advisory from 9 AM this morning to 2 AM PST Friday for Orange County Coastal Areas-Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire- San Diego County Coastal Areas-San Diego County Valleys- Santa Ana Mountains and Foothills.
Winter Storm Warning until 9 AM PST Friday for Riverside County Mountains-San Bernardino County Mountains.
Winter Weather Advisory until 9 AM PST Friday for San Diego County Mountains.
Wind Advisory until 9 AM PST Friday for Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts-San Gorgonio Pass near Banning.
PZ, Small Craft Advisory until 10 AM PST Friday for Coastal Waters from San Mateo Point to the Mexican Border and out to 10 nm- Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.
