Cooler temperatures with shower chances and high elevation snow through Tuesday. A few thunderstorms will be possible Monday. Dry weather returns Wednesday and Thursday before shower chances return at the end of the week.
Discussion
Mostly cloudy skies cover the region early this morning. The initial front has weakened as it has moved south to around I-80 accompanied by scattered very light showers. Rainfall amounts overnight have only been a few hundredths of an inch, mostly over the the northern mountains and northern Sierra. Snow levels remain quite high – over 7k ft north of Redding, and over 10k ft in the northern Sierra.
Current temperatures are very mild, mainly in the 40s and 50s in the mountains, and mid 50s to mid 60s across the Central Valley. Cooler and wetter weather is expected across the region the next several days as the upper trough over the Gulf of Alaska approaches today and Monday, then moves onshore on Tuesday.
Precipitation amounts through Tuesday aren’t overly impressive given the weak AR ahead of the trough – around an inch or two are likely over the mountains with most of the valley expected to be under 0.50″. Some heavier rainfall rates (around 0.50″/hr will be possible this evening over Shasta County as the next front drops south with some embedded deep convection.
This front will also weaken as it drops south later tonight and Monday, but snow levels will drop behind it allowing a few inches of snowfall accumulation over the higher northern Sierra passes beginning early Monday morning, and some minor travel impacts may be encountered.
Showery precipitation will develop later Monday into Tuesday with the upper trough moving in, and a few thunderstorms will be possible.
Dry weather is forecast to return by late Tuesday evening continuing Wednesday. Enough cloud cover is expected Tuesday night to help keep valley temperatures up, but clearing Wednesday night may lead to chilly temperatures by early Thursday with some patchy frost possible in colder portions of the valley.
Extended Discussion (Thursday through Sunday)
Dry weather expected Thursday as upper level ridging progresses through interior NorCal. Next Pacific frontal system progged to weaken as it pushes into the CWA Friday. Associated precip looks light with limited QPF.
Dry weather forecast for Saturday under weak upper level ridging. Weak short wave trough progresses through Sunday, again with limited QPF ahead of upstream stronger system for early next week.
Below normal high temperatures forecast through the extended period.