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.
Record dry January expected in many Northern and Central California cities as drought drops reservoir levels.
The United States Department of Agriculture says January is shaping up to be another dry month in the Lake Tahoe area and that signals an unprecedented fourth year of drought.
You'll want to use extra caution on the roadways, as it's another foggy morning in the region.
Thick fog is blanketing the Sacramento area.
Forecasters issued a dense fog advisory Tuesday morning.