The ridge is no longer off the coast of CA but is now further North off the Pacific NW & British Columbia. That is going to help push a strong cold front through later today. You will feel the difference tomorrow with highs only in the 20's and 30's. The temps should then moderate through the end of the week into the 40's.
The PNA is now negative and the teleconnections are aligned for a progressive pattern and no long periods of ridging for at least the next few weeks. The ridge is going to move East this weekend as a new ridge forms out around 160-170w just South of the Aleutians. That is going to open the door to storms and cold air. The first storm this weekend will weaken as it hits the back of the departing ridge which is common with the first storm after a long dry spell. Not expecting much if any precip over the weekend as this storm is just the full back clearing the way for bigger storms next week.
The first big storm should arrive next Tuesday and last into Wednesday. The second storm arrives Thursday and lasts through Friday. These will be cold storms with low snow levels which will aid in the accumulations with high snow ratios. Right now it's too early for predicting amounts but we will be measuring in feet over the 5 day period of Tuesday Saturday.
The pattern stays favorable for cold storms to continue to dive in going into the end of the month. With the ridge wanting to make its home out around 160w, low pressures should continue to drop into the Pacific NW and drag snow and cold into Tahoe. We will have breaks with possible brief ridges, but any ridges should be short lived and continue East allowing a storm every few days.
Things will look and feel a whole lot different around here next week. Winter is only half way through so be prepared for the cold and snow that is coming. Stay tuned........BA