A weak system will begin to push into the Northstate today and tomorrow. Expect increasing clouds and scattered mountain showers by tonight.
This first system is helping to break down the ridge and moisten up the atmosphere. Think of this system as the primer.
The strong front/low arrives Wednesday into Thursday, with precipitation chances going up from Wednesday morning. At this moment it appears this storm has a lot of boom/bust potential. Some models bring nearly 1" to parts of the valley floor, whereas some models bring less than 0.10". For now just cutting the difference with rain totals between 0.25-.050" for the valley with heavier amounts towards Redding.
This system is tapping into a warm subtropical air-mass. Moisture plume is originating just southeast of Hawaii. The coldest air will remain well off to the north and northwest through majority of the event. Snow levels well above 7,000ft through Wednesday. We'll finally see a shot of cold air on the backside by Thursday morning. The case with a lot of these storms the cold air will be chasing the moisture.
The ski park will likely see mostly rain with some snow showers by Thursday.
Unfortunately most models have the West Coast ridge building back in by the beginning of next week.