CNN
 — 

Storm-battered California communities are bracing for another round of likely flooding, mudslides, toppled trees, closed roads, power outages and even perhaps a few brief tornadoes as the latest in an unrelenting parade of atmospheric rivers hits the West Coast.

The storms Monday into Tuesday are expected to bring another surge of hazardous heavy rain, mountain snow and damaging winds to California, where thousands are already without power and some have been ordered to evacuate or warned they could be asked to flee.

“We expect to see the worst of it still in front of us,” Gov. Gavin Newsom said Sunday.

TRACK THE STORMS

Over 34 million people are under flood watches across much of California. A moderate risk – level 3 of 4 – of excessive rainfall covers over 26 million people in the state, including in San Francisco, Sacramento, Los Angeles and Fresno, where rain could fall at 1 inch per hour. Wind alerts also are in place for much of coastal California and into the mountains.

The series of recent storms has deluged a state that’s faced a historic drought and fierce wildfires that have scarred the landscape. Much of California cannot bare to absorb more moisture without the possibility of even more flooding.

Two major bouts of rain are expected to impact the West Coast over the next few days, without much of a break between events for the water to recede. The system is part of an atmospheric river – a long, narrow region in the atmosphere that can transport moisture thousands of miles, like a fire hose in the sky.

“While some of the forecast rain totals are impressive alone, it is important to note that what really sets this event apart are the antecedent conditions,” the National Weather Service office in San Francisco said. “Multiple systems over the past week have saturated soil, increased flow in rivers and streams, and truly set the stage for this to become a high impact event.

In Sacramento County, evacuation orders have been issued for the community of Wilton along the Cosumnes River, with officials warning “flooding is imminent” and residents should leave before roads become impassable. The community was ordered to evacuate during last week’s storm, when exit routes flooded quickly, officials said.

El Dorado, Monterey, Santa Cruz and Santa Clara and Alameda counties have issued evacuation warnings or recommendations for some areas due to possible flooding and other safety risks, with forecasters warning of swelling rivers.

Damaging winds are expected through Monday across Northern California and into Nevada, spurring fears of more downed trees and widespread power outages. Wind gusts up to 65 mph are expected, the National Weather service in Sacramento warned.

Wind gusts topping 100 mph were already being reported across the region by early Monday morning, including a 132 mph gust near Oroville, California.

More than 128,000 homes and businesses across California had no power early Monday, according to PowerOutage.us – down from over 400,000 without electricity a day earlier after high winds and rain swept in.

As the storms pummel California, Newsom on Sunday submitted a request to the White House for an emergency declaration to support response and recovery efforts.

“We are in the middle of a deadly barrage of winter storms – and California is using every resource at its disposal to protect lives and limit damage,” Newsom said in a statement. “We are taking the threat from these storms seriously, and want to make sure that Californians stay vigilant as more storms head our way.”

This storm system arrives on the heels of a powerful cyclone that flooded roads, toppled trees and knocked out power to much of California last week. Earlier, a New Year’s weekend storm system produced deadly flooding.

Twelve Californians have died from “storm-related impacts,” including flooding, since late December, according to Newsom’s office.

“Floods kill more individuals than any other natural disaster. We’ve already had more deaths in this flood storm since December 31 than we had in the last two fire seasons of the highest fire acreage burned in California,” said California Emergency Services Director Nancy Ward during a news conference Sunday.

“If you don’t have to be traveling during peak period in the storm, please don’t,” said state Secretary of Natural Resources Wade Crowfoot. “Be prepared for power outages and other interruptions. Have those flashlights, the candles, batteries, charge cell phones at the ready.”

Already, flooded roadways and toppled trees and power lines are making travel difficult, according to the California Highway Patrol. Around Northern California over the weekend, downed trees crushed cars and homes, images show.

“Just a foot of water and your car’s floating. Half a foot of water, you’re off your feet. Half foot of water, you’re losing control of your vehicle,” Newsom said. “We’re seeing people go around these detours because they don’t see any obstacles – they think everything is fine, and putting their lives at risk or putting first responders lives at risk.”

Crews, including from the California National Guard, are prepared to move out quickly in the event of mudflows, avalanches or flash floods, state officials said Monday.

California is experiencing “weather whiplash,” going from intense drought conditions to now contending with its fifth atmospheric river, Newsom said.

“It’s just a few months ago we were talking about these heat domes and extreme heat,” Newsom said.

Much of the state has already seen 5 to 8 inches of rain over the last week. Two to 4 more inches of rain are expected across the coasts and valleys – and even more in mountains and foothills through Tuesday.

Flooding and mudslides are among the biggest concerns – especially on soil that’s already been saturated by the barrage of storms, as well as in sensitive areas recently scorched by wildfires.

Water from swelling rivers could spill over and inundate communities.

The rainfall over the weekend brought renewed flood concerns for streams, creeks and rivers. The Colgan Creek, Berryessa Creek, Mark West Creek, Green Valley Creek and the Cosumnes River all have gauges that are above flood stage or expected to be in the next few days.

“The cumulative effect of successive heavy rainfall events will lead to additional instances of flooding. This includes rapid water rises, mudslides, and the potential for major river flooding,” the National Weather Service said.

The moisture is expected to sink southward Monday night, making flooding “increasing likely” over the Southern California coastal ranges Tuesday, according to the weather service. And another round of strong winds is expected to accompany the storm as it pushes inland.

“Valley areas will likely see gusts as high as 45-50 mph, with gusts greater than 60 mph possible in wind prone areas,” the weather service office in Reno said, adding the Sierra Ridge could receive peak gusts between 130 to 150 mph Monday.

Meantime, residents at the higher elevations are being warned about heavy snow and strong winds.

As the storm pushes inland, more than 5 feet of snow could fall along the Sierra Crest west of Lake Tahoe, the weather service said.

The heavy snow, coupled with strong winds, will also lead to near whiteout conditions on roads.