The National Weather Service says a significant storm will bring between a quarter and a half-an-inch of rain to the valley and up to 2.5 inches of rain to the Sierra.
David Rowe with the weather service says there will be snow too.
"Probably about a foot to a foot and a half at the ski areas and maybe 2 to 3 inches down to about 4,500 feet," says Rowe.
Rowe says there are also flooding concerns in areas scarred by wildfire last summer -- for example the Rim Fire near Yosemite.
"When you get heavy rainfall intensity in a short amount of time, you tend to get mud and dust and debris left over from the fires last summer that'll accumulate and run downhill," he says.
Rowe says this will be a significant storm, but the region needs a series of these storms to start recovering from the drought. He says the forecast is dry again for the weekend and early next week.
Rowe urges valley commuters to use caution, especially Thursday morning, when the roads are likely to be slick, and says chains will likely be required in the Sierra.
The weather is about to change. Attached is the NOAA prediction for snow onI-80. Be prepared for winter driving. pic.twitter.com/kEvvfGXHAo— Caltrans District 3 (@D3PIO) January 28, 2014
Spring storms help Sierra Nevada snowpack, but there is no reduction in drought conditions in California and Nevada.
More "Spare The Air" alerts may be issued this year in the Sacramento region because the Environmental Protection Agency has lowered the federal ozone health standard.
Weather permitting, the Tahoe Douglas Fire Protection District and the U.S. Forest Service may continue prescribed fire operations starting Monday in areas around Lake Tahoe.
(AP) — Storms brought deep snow to the mountains that feed the vital Colorado River this season, but the dried-out landscape will soak up some of it before it can reach the river.
(AP) - California water managers say they're easing cutbacks as spring storms boost reservoirs in the state's five-year drought.