The potential for scattered rain and snow showers is lingering across portions of Northern California this evening and there is a slight threat of thunderstorms in the valley and foothills. A Winter Weather Advisory is still in effect through noon on Friday for the Western Slopes of the Sierra above 2500'. The best chance for wet weather is in areas of Butte and Plumas Counties. Snow levels are mostly above 2500' tonight. The heaviest rain and snow is now well down to our South. Some modest travel impacts can be expected in the mountains this evening. Temperatures topped out in the high 40's to low 50's in the valley this afternoon, and mountain areas mostly ended up in the 30's. Temperatures will become very cold overnight. Valley areas are projected to dip into the mid 20's to mid 30's, and most mountain areas will end up in the teens on Friday morning. There will still be potential for some scattered mountain snow showers on Friday, but travel impacts shouldn't be a major concern.
A strong, but warmer winter storm is going to move into the West Coast this weekend bringing heavy rain to the valley and heavy snow to the mountains. We currently have a Winter Storm Watch in effect from 4am on Saturday through noon on Sunday, but that will more than likely be upgraded to a Winter Storm Warning. Travel impacts are expected to be substantial. Rain and snow will move into the Northern Mountains early on Saturday and will spread into the valley later in the morning. Heavy snow will return to the Sierra around noon on Saturday. Snow levels are expected to start out at around 2000' on Saturday morning, but will lift to around 3000' by Saturday evening. Snow levels will then rise to around 4000' on Sunday. Between 2 to 3 feet of snow can be expected in higher elevations and that will make mountain travel treacherous through Monday. This wet system will start to wind down late Sunday into Monday, but showers could linger into your Tuesday forecast. Temperatures will warm back into the low to mid 50's in the valley on Sunday into Monday and will continue to climb on Tuesday. Valley areas could end up back in the high 50's to low 60's on Tuesday afternoon. Anorther wet system is projected to bring more wet weather on the way towards the end of next week.