The weather through the weekend will be seasonal with sun, light winds, and temperatures in the 40's on the mountains. That all begins to change next week as a very cold trough begins to make its way South down the West Coast towards Tahoe.
We should begin to feel the effects of this by Monday as the winds begin to pick up and clouds could move in by Monday night. On tuesday the much colder air along with wind should begin to pour in from the North. This will be a very slow moving system that will bring cold air through the end of the week.
This system will also bring snow but the question is how much. The forecast models have been trending towards a wetter scenario as the cold trough and low pressure shift very slowly South down the West coast through the week. That could lead to a prolonged period of snowfall Tuesday through Thursday.
Snowfall amounts are uncertain at this time. If the center of low pressure moves down over the ocean we could see more precip. If it moves down over land we could see less. The current model runs show quite a bit of snowfall possible over the 3 day period. A safe bet right now is for several inches of snow, but we will watch closely as several feet of snow is possible if this sets up just right.
After Thanksgiving the pattern looks to remain active. With high pressure centered well to our North the storm door should remain open to more storms the following weekend and into December.