A weather system will bring widespread showers, moderate mountain snow, and isolated thunderstorms late tonight into Wednesday. The latest precipitation and snow amounts have trended slightly lower, but we’re still expecting minor impacts from rain and moderate mountain snow. Snow levels are now expected to be around 6000-7000 feet on Tuesday, falling to around 5500 feet Wednesday. The heaviest snow is still expected Tuesday afternoon into Wednesday morning.
Breezy northerly winds have been observed across portions of the Valley today, with gusts to around 20-30 mph. The next system approaches from the eastern Pacific this evening, with some rain and snow showers developing ahead over the Sierra.
Tuesday through Wednesday
A weather system will move through the area Tuesday into Wednesday, bringing widespread rain showers, moderate mountain snow, breezy winds and isolated thunderstorms. The heaviest precipitation is expected Tuesday afternoon through Wednesday morning.
A Winter Weather Advisory remains in effect from 10 pm Monday through 4 pm Wednesday for the northern Sierra and the southern Cascades and Lassen Park above 5500 feet. Snow levels have trended higher and will be rising to around 6000 to 7000 feet Tuesday, dropping to around 5500 feet Wednesday. Latest snowfall totals have decreased, with 3 to 6 inches expected above 5500 feet, 8 to 12 inches above 6000 feet, and up to 18 inches possible over higher peaks. Expect delays and chain controls on mountain freeways such as I-80 and US Highway 50.
Rainfall amounts in the Valley are expected to be generally around a half inch to an inch, though they could be locally higher in thunderstorms. This should limit impacts from rainfall to be mainly slippery travel on roads.
The latest probability of thunderstorms sits around 15-20 % for Tuesday afternoon through Wednesday, highest probabilities centered over the southern Sacramento Valley, the northern San Joaquin Valley and into the foothills.
Friday and onward
A potentially wetter and colder system arrives late Friday night through early next week, which could bring heavy mountain snow, widespread rain and breezy winds. The colder air means lower snow levels, possibly into the upper foothills.
With increased travel due to the Presidents Day holiday, next weekend could see significant travel impacts. At this point, the heaviest precipitation appears to be Sunday into early next week. There remains uncertainty about this storm, especially the timing, which has recently trended a little later more into early the next week. Stay tuned as more details become available!
The Climate Prediction Center 8 to 14 day outlook favors below normal temperatures and above normal precipitation for the February 16th through 22nd timeframe, leaning towards the active weather pattern continuing through the 3rd week of February.