A little cooler today than yesterday under cloudy skies, with southwest to west winds gusting 35 to 45 mph in the mountains and deserts during the afternoon and evening. The flow will turn offshore on Friday, with warming for the coast and valleys and continued cooling for the deserts. There will be north to northeast winds along and below the coastal slopes of the mountains, peaking Friday morning with gusts to 35 to 45 mph. For the weekend, weaker winds and warmer inland with Sunday high temperatures 5 to 10 degrees above average. Some time during the early to middle part of next week, a low pressure system will move into California bringing cooler and breezy weather with a less than 20 percent chance of measurable precipitation.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
This afternoon, a low pressure system to our southwest continues to bring widespread mid and high clouds to SoCal, along with onshore flow and slightly lower temperatures. The marine layer has been disrupted by this system and there is no significant inversion and very few low clouds, mostly over the coastal waters. As this system moves inland over northern Baja this evening and tonight, the onshore flow will strengthen briefly producing westerly winds locally gusting 35 to 45 mph in the mountains and deserts.
For late tonight into Friday morning, a surface high will move into the Great Basin, briefly setting up offshore flow. Gusty north to northeast winds will develop early Friday morning, peak during the day and weaken Friday evening. Gusts of 35 to 45 mph are expected in and below the Cajon Pass, along and below the coastal slopes of the Santa Ana Mountains, and in northern and eastern portions of the Coachella Valley. The offshore flow will also bring about 5 degrees of warming to the areas west of the mountains but the deserts could be about 5 degrees cooler than today. High temperatures on Friday will be mostly in the 70s for the coast and valleys to around 80 for the western valleys and inland coastal areas with high temperatures for the lower deserts in the lower to mid 80s.
The offshore winds will weaken on Saturday and a transient ridge of high pressure ahead of a low pressure system, developing south of the Gulf of Alaska, will bring daytime temperatures about 5-10 degrees higher than Friday. High temperatures are expected to range from the lower 70s near the coast to the lower to mid 80s for the Inland Empire with the lower deserts around 90.
Warming will continue for inland areas on Sunday under southwest flow aloft ahead of the low pressure system moving southward off the CA coast. High temperatures on Sunday will likely be 5 to 10 degrees above average for most areas. Sunday high temperatures will range from the lower 70s near the coast to the lower to mid 80s for the Inland Empire with the lower to mid 90s for the lower deserts.
For Monday through the middle of next week, Model solutions have not yet begun to converge on a solution so forecast details are quite uncertain. The low pressure system will move inland over CA by Wed or Thu. We can say with reasonable confidence that conditions will be cooler and breezier with increasing clouds. Almost half the ensemble members across model platforms indicate the potential for measurable precipitation but timing and amounts are uncertain. At this time, the National Blend of Models indicate a 15%-25% chance of measurable precip between next Tue and Thu.
161800z, Coast, Low clouds along the coast this morning have since scattered out, with VFR conditions expected through the afternoon. There is a window of low clouds (near 2000ft MSL)to temporarily move back into the coastal TAF sites between 04-08z Friday before offshore flow sets in and pushes any clouds back off the coast.
Valleys/Mountains/Deserts, Strong southwest to west winds are expected through 06z this evening with gusts up to 30 to 40 knots, particularly in the mountains and deserts. MOD up/downdrafts in lee of mountains, along with local BLDU in deserts. Winds to shift to offshore (northeast) after 06z tonight in the coastal foothills and into the northern Inland Empire, increasing Friday morning.
Otherwise, BKN high clouds AOA 20000 feet MSL decreasing after 00Z. VFR conditions expected today through tonight.
No hazardous marine conditions are expected through Monday.
Ca, Wind Advisory from 5 AM to 5 PM PDT Friday for Orange County Inland Areas-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-Santa Ana Mountains and Foothills.
Wind Advisory until 2 AM PDT Friday for Apple and Lucerne Valleys.
PZ, None.
