Update 6 a.m.
Heavy rain in the valley could start as early as 6 a.m. By the mid-morning hours, downpours and strong winds will make driving difficult. As much as .50-1.00 inch of rain is expected in the valley and foothills.
Snow levels will fall to about 2,500 feet bringing light accumulations above 2,000 feet. As much as 1-2 feet of snow possible through Friday morning. Local spots at higher elevations may see 3 feet of snow developing.
Valley low temperatures will be in the 40s. Snow could develop in the Sierra with lows temperatures in the 20s. A Winter Storm Warning in effect with possible road closures.
Update: 1:00 p.m.
Heavy snow and gusty winds are expected for the Sierra during the day on Thursday. At least 1 to 2 feet of snow is possible above 3,000 feet in elevation.
Rainfall for the Valley will range from half an inch to 1 inch for most locations. Higher rainfall amounts are expected for the Foothills and Sierra.
Snowfall is expected from the upper Foothills to the Sierra. Snow levels will begin around 3,300 feet in elevation and fall to 2,500 feet in elevation during the day.
As the front works through the area, there's also a risk of thunderstorms during the day on Thursday. Any thunderstorms that develop are capable of producing small-sized hail and heavy downpours.
The biggest winter storm in weeks will be moving through California on Thursday. Showers will begin early in the morning with the heaviest rain hitting during parts of the morning commute.
It's likely that heavy rain and wind will hit the Sacramento and San Joaquin Valleys during the morning, with thunderstorms possibly following during the afternoon.
Rain totals in the valley will be near 0.50-1.00 inches by late Thursday afternoon, and some foothill locations could see 1.00-2.00 inches of rain.
With this amount of rain, there could be some ponding on roads, making travel difficult during the morning.
This is a cold storm with snow level starting around 4,000 feet, then lowering below Pollock Pines through the day to near 3,000 feet. It will also put snow on the ground near Grass Valley and Foresthill.
By Friday morning, widespread snow is possibly near 2,500 feet.
A Winter Storm Warning starts at 6 p.m. on Wednesday and will run through Thursday at 4 p.m. Expect big travel delays on Sierra roads and possible closures.
Dry weather is expected again Friday with a slight chance of showers returning late Saturday.
For more on your local weather, follow Monica Woods on Facebook.
READ MORE THE LATEST NEWS FROM ABC10:
FOR NEWS IN YOUR COMMUNITY, DOWNLOAD THE ABC10 APP:
►Stay In the Know! Sign up now for ABC10's Daily Blend Newsletter