The rain has largely stopped after one of the wettest winters in California. But as spring temperatures begin to climb and snow in the Sierra Nevada melts, the threat of flooding has communities across the Central Valley on edge. The storms that set a rainfall record in Northern California have left a vast layer of mountain snowpack, which now sits at almost 200% of average for the first week of May. In some areas, the snow is 80 feet deep, according to state and NASA reports.