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.
6/28/16 UPDATE - Forecasters are predicting record heat in the Sacramento region Tuesday with temperatures reaching 108 degrees downtown.
After several days of sweltering heat, Sacramento residents can expect cooler weather this week. Temperatures will remain in the mid-90s for Monday.
Heavy thunderstorms are moving through Plumas County Sunday evening.
Friday is expected to be the hottest day of the week with triple-digit temperatures hitting much of the Central Valley, according to the National Weather Service.
CHP is requiring chains on I-80 between Donner Lake Rd. to Nyack and Eastbound 1-80 at Drum Forebay is closed due to heavy snow and multiple accidents. Downtown Sacramento's Concert in the Park was cancelled due to the weather.