Cooler mostly cloudy weather will continue through Thursday. Precipitation, mostly light, will occur at times, and after today, the best chances of rain will be Thursday with a deeper trough of low pressure moving through the region. Strong gusty winds will occur most of the time through Tuesday night in the mountains and deserts with gusts 45 to 55 mph, isolated to 70 mph. Coastal areas will be windy Tuesday afternoon and night as well. Drier warmer weather will return by the weekend and continue into early next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Light rain covered most areas from the mountains west to the coast early this morning, but radar shows that rain mostly retreated to the south half of San DIego County as of around 1000 AM. A few locations over higher terrain have exceeded 0.30" of rain with Lytle Creek Canyon having recorded 0.59". Otherwise, mostly cloudy skies prevail, including high clouds over the desert. A few light showers will continue this afternoon, mainly over higher terrain. Local winds to around 50 MPH are occurring and will increase some this afternoon with local gusts over 60 MPH by late afternoon on the desert mountain slopes and through San Gorgonio Pass.
The main upper low was centered just off the Oregon coast with zonal flow but with tight height gradients to the south. The upper low will gradually dig south and bring well-defined cyclonic flow over California by Tue. A rather vigorous short wave will move through SoCal Tue night, and ahead of that, there will be strong winds not just in the mountains/deserts but also along the coast and over some valleys. This should be soemwhat of an enhancer of the precip mostly in the mountains Tue night. Another short wave Thu will move through the long-wave trough which will be both deep and broad by then, coupled with a strong upper ridge over the SE US. That wave will bring another round of precip, with most model/ensemble guidance suggesting 0.10"-0.25" with highest values in the foothills. We will raise PoPs for Thu given the relative consistency in the models and the well-defined trough axis being nearly overhead. A few inches of snow could fall in some of the mountains as snow levels will fall to around 4500 feet. Nbm 50th percentile snowfall has less than one inch in San Bernardino County, but 90th percentile snowfall is 2-4 inches Thu.
The trough will shift east Friday and be centered over AZ/NM with some cyclonic flow continuing here with ridging building from NorCal north through the PacNW. Some cyclonic flow even continues Sat in about 60% of the ensembles per the cluster analysis. A few showers could linger Fri over higher terrain but most likely it will be dry. The increase in temperatures will be based partly on the proximity of the ridge relative to the trough but warming should occur Fri- Sun, with temperatures near or slightly above normal starting Sat and with about a 70% chance of temps 5-10 degrees above normal Sun- Mon.
311645z, Coast/Valleys/Foothills, Low clouds with -SHRA and cigs 1500-2500 feet MSL, locally down to 500 feet with vis 2SM in -RA will continue generally all day. Tops will be to 6000 feet MSL and higher terrain will be obscured much of the time. Conditions improve 00-06Z and overnight into Tuesday from northwest to southeast, with bases lifting to 1500-2500 feet MSL, vis mostly P6SM, and only patchy terrain obscured.
Higher Mountains/Deserts, SCT-BKN clouds AOA 15000 feet MSL today and tonight. Strong westerly winds continue today. Gusts 30-50 kts over the ridges and in wind-prone mountain passes, with gusts 25-35 kts within the open deserts. Areas of moderate up/downdrafts, including localized LLWS and rotors, in lee of mountains and mountain passes.
Calmer seas and winds over the waters today but hazardous conditions likely return on Tuesday. A short period (7-8 seconds) northwest swell (290-300 degrees) arrives early Tuesday, bringing very steep and choppy seas to 10-13 feet. Winds increase substantially as well, gusting to 30-35 knots in the outer waters and to 25-30 kts for the nearshore waters. Winds peak Tuesday night into Wednesday morning. Winds and seas slowly fall on Thursday. A Small Craft Advisory remains in effect tonight through Tuesday afternoon ahead of the Gale Watch for Tuesday afternoon through Wednesday morning.
Elevated surf of 3-6 feet today, with associated moderate to high rip current risks possible. Higher surf develops Tuesday and Wednesday to 5-7 feet and sets to 8 feet, locally to 10 feet for west-facing beaches. A high rip current risk will exist for all beaches for both days.
Ca, Wind Advisory until 2 AM PDT Wednesday for Apple and Lucerne Valleys-Coachella Valley-Riverside County Mountains-San Bernardino County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.
PZ, Small Craft Advisory from 2 AM to 3 PM PDT Tuesday for Coastal Waters from San Mateo Point to the Mexican Border and out to 10 nm.
Gale Watch from Tuesday afternoon through Wednesday morning 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.
Small Craft Advisory from 10 PM this evening to 3 PM PDT Tuesday for Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.
