A few light High Sierra showers late tonight into early Tuesday, otherwise dry conditions prevail with a gradual warming trend. Gusty north to east winds develop late tonight and persist through early Wednesday, strongest on Tuesday and in the mountains.
Discussion
Mostly clear conditions are being observed across interior Northern California this morning. Temperatures are sitting in the 40s across much of the Valley and foothills, with mountain temperatures in the 30s. Chances for patchy Valley fog return this morning with short term guidance indicating a 40 to 60% chance of visibilities less than 1/2 mile across portions of the Valley and Delta. Be sure to slow down and turn on low beam headlights when driving through fog!
Dry conditions will prevail this week, outside of a few High Sierra showers or snow showers late tonight through early Tuesday. Little to no impacts are expected as precipitation is fairly light and confined to the higher elevations of the Sierra Crest. Gradually warming temperatures are also favored this week, with high temperatures in the 50s to 60s for the Valley.
An upper level trough will dig southward over the Great Basin early this week, with upper level ridging over the Eastern Pacific. A strong pressure gradient will allow for gusty north to east winds to develop tonight and persist through Wednesday morning. The National Blend of Models (NBM) shows a 75-95% probability of wind gusts of 30 mph or greater in the Valley west of Interstate 5, and a 50-70% probability of wind gusts of 60 mph or greater over the higher peaks of the Sierra Nevada.
A Wind Advisory is in effect for portions of the West Slope Northern Sierra Nevada, Western Plumas/Lassen Park, and Northeast Foothills including Highway 70/Jarbo Gap until 7 AM on Wednesday.
These gusty winds can make driving difficult, especially for high profile vehicles. People in the mountains should use extra caution while driving, be alert during outdoor activities, and secure any loose outdoor objects such as holiday decorations. Winds will gradually weaken in the Valley through Wednesday afternoon, but will still be gusty over the mountains into Thursday morning before tapering off Thursday afternoon.
Be sure to stay up to date with the latest forecast at weather.gov/sto!
Extended Discussion (Friday through Monday)
EPAC upper ridge remains dominate synoptic feature through the extended forecast period. A few weak short waves progged to drop south over eastern portions of the CWA Sunday into Monday, but forecast remains dry. Areas of gusty north to east wind Saturday into early next week.
Above normal high temperatures forecast Friday into Monday with upper 50s to 60s in the Central Valley and 40s and 50s for the foothills and mountains.