Another 'powerful' atmospheric river drenches California

Another "powerful" atmospheric river is expected to impact a large portion of the West Coast in the coming hours and days, drenching a drought-ravaged region, forecasters said.

Like rivers in the sky, the incoming storms will dump even more rain and snow over California and western Nevada, beginning Sunday night and peaking in intensity Monday into Tuesday, according to the National Weather Service (NWS).

The latest forecast shows "two major episodes of heavy precipitation" impacting California "in quick succession," along with "two of the more energetic and moisture-laden parade of cyclones that are aiming directly for" the Golden State, the NWS said. The first episode, which began streaming into central California on Sunday night, "is expected to be the more robust of the two," resulting in rainfall totals of 3 to 5 inches near the coast, according to the NWS.

The second episode is expected to quickly arrive Tuesday with less heavy rainfall totals but "impacting locations farther south into southern California," the NWS said. The Sierra Nevada, which stretches along the eastern edge of California, will likely see snowfall totals "exceeding 6 feet across the higher elevations before the snow tapers off Wednesday morning," according to the NWS.

The forecast shows hourly rainfall totals are likely to steadily increase through Tuesday morning, reaching 1 inch in central California's coastal Santa Lucia mountain range. Elsewhere, peak hourly rainfall totals of 0.5 to 1 inch can be expected. The cumulative effect of successive heavy precipitation combined with gusty winds will lead to additional instances of flash flooding and debris flow -- especially in burn scars and other areas of sensitive terrain -- as well as mudslides and rapid rises of creeks, streams and rivers, according to NWS.

"Significant" impacts to Travel and infrastructure, including possible power outages, road closures, downed trees and snow load, can also be expected, the NWS said. Residents and visitors across the affected region have been advised to check their local forecast, never drive across flooded roadways and have both an emergency kit and evacuation plan in place.

California Gov. Gavin Newsom warned Sunday that the worst of the storms was yet to come. He said officials were preparing by activating emergency response teams and staging equipment throughout the state. The governor's office also submitted a request to the White House for a presidential emergency declaration.

In Northern California, the Sacramento County Office of Emergency Services issued an evacuation order on Sunday for residents living in the Wilton area, along the Cosumnes River.

"Flooding is imminent. Out of an abundance of caution, residents must leave now before roads become impassable," the evacuation order stated. "Rising water may spill over onto the nearest roadways and cut off access to leave the area. Last weekend, exit routes flooded quickly for residents leaving Wilton, so we are urging residents to get out now."