The second storm, forecasters say, could bring thunder and dump up to 2 inches of rain in central and southern valleys, 2 to 4 inches in the foothills and up to 6 inches in some mountain spots.
State water officials plan Thursday to survey the anemic mountain snow pack, and will likely find that California's precipitation is badly lagging what's needed to quench the region's thirst. 2013 was California's driest year on record.
In Nevada, the first of back-to-back storms dropped several inches of snow at Lake Tahoe and up to a foot and one-half on the mountain ridges.
A winter weather advisory was put into effect from 4 p.m. Wednesday to 10 a.m. Thursday for the Reno-Tahoe area, south to Mammoth Lakes.
The second wave of wetter weather begins Friday night into Saturday.
A winter storm is forecast to bring mostly rain in the Sierra Nevada Friday, with high snow levels. But Saturday, snow is expected at lower elevations.
The National Weather Service in Sacramento has issued an urban and small stream flood advisory for several counties in the region including: Sacramento, Yolo, Calaveras, Amador, San Joaquin and Stanislaus.
UPDATE 9 a.m.: The thousand-mile coast of California is covered in warnings, watches and advisories for rain, flooding and high surf as another El Nino storm moves in from the Pacific. Winter weather advisories are also in effect in Nevada.
Several storm systems queued off the coast will bring several inches of rain to the Sacramento Valley this week.
(AP) - Parts of California remain in the grip of a cold spell. The National Weather Service issued a hard freeze warning for much of the San Joaquin Valley through 10 a.m. Thursday.