The Weather Prediction Center has issued a level 4 of 4 warning of excessive rainfall in some California areas | CNN

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Officials in California issued evacuation warnings in portions of several counties amid powerful storms likely to deliver severe rainfall and cause widespread flooding across the central and northern parts of the state Friday.

The most dangerous amount of rain could impact nearly 70,000 people along the central California coast, stretching from Salinas southward to San Luis Obispo and including parts of Ventura and Monterey counties, according to the Weather Prediction Center, which issued a level 4 of 4 warning of excessive rainfall in the area.

“Multiple rounds of rainfall in addition to melting snow will result in the potential for significant rises along streams and rivers, with widespread flooding impacts possible through early next week,” the National Water Center said Thursday.

Creeks and streams in the foothills of the Sierra Nevada mountains remain the most vulnerable areas for flooding from rain and snowmelt, the Weather Prediction Center said.

Roughly 17 million people are under flood watches in California and parts of Nevada as of late Thursday. Heavy rain had already begun Thursday, with the worst rainfall and most significant impacts expected to persist through the day Friday. Hourly rainfall rates will steadily increase in intensity across California from Thursday overnight through Friday morning, potentially reaching 1 inch per hour.

The threat has pushed local officials to issue evacuation warnings and orders for some areas in the storm’s most precarious path as well as remind residents to prepare for yet another bout of severe weather – all while much of California remains in recovery mode from prior heavy snowfalls and deadly flooding in January. Additionally, California transportation officials have partially closed Interstate 5 and Highway 1, two major roads in the state.

In the community of Felton in Santa Cruz County, resident Tom Fredericks lamented the fatigue from the unrelenting series of severe storms since the start of the year.

“We’ve been working every week, every week when we can since then,” Fredericks told CNN affiliate KGO. “It’s just starting right now to feel like it was before the storms. So this is kind of discouraging to be facing it all over again.”

In nearby Monterey County, nearly 40,000 homes and businesses – roughly 20% of customers tracked – were without power as of Thursday night, according to PowerOutage.us.

In San Luis Obispo County, officials issued an evacuation order beginning Thursday night for residents south of the Arroyo Grande Creek Levee, urging them to seek higher ground for safety. A pet-friendly American Red Cross Shelter in the county is available to residents. Meanwhile, an evacuation warning remains in place north of the Arroyo Grande Creek Levee and near the Oceano Lagoon.

Here’s where evacuation warnings are in effect:

As of late Thursday, 34 of California’s 58 counties are under a state of emergency issued by the governor’s office due to previous storms and this week’s severe weather threat. The state also activated its flood operations center Thursday morning.

Gov. Gavin Newsom’s office on Thursday also asked the White House to approve a Presidential Emergency Declaration to support state and local responses to the severe weather the state has been enduring since last month.

“These storms have already caused significant damage in California from the substantial rain, snowfall, and river and urban flooding. It is expected the incoming atmospheric river system will bring heavier precipitation, creating greater impacts and compounding the complexities of response and recovery the affected counties that are still responding to effects of the December 2022-January 2023 winter storm event,” the governor’s request says.

If approved, the emergency declaration would allow impacted counties to immediately access federal assistance to help protect public safety and property, the governor’s office said. The request for funds would apply to generators, road clearance equipment and potential sheltering and mass care assistance.

Friday’s impacts come as millions in the storm’s path have not had time to bounce back from multiple rounds of recent steep snow that buried some neighborhoods and roads while leaving many stranded as they ran low on important supplies.

From late December into January, many areas across the state were inundated with torrential rain from atmospheric rivers that lasted for consecutive days. The rainfall caused deadly flooding, mudslides and damaged critical infrastructure that has not been yet repaired in some places, which elevates the potential danger associated with this week’s storm.

This week’s atmospheric rivers – which are long, narrow bands of moisture in the atmosphere that carry warm air and water vapor from the tropics – could possibly be even more threatening due to their warmth, forecasters have said.

“The abnormally warm and wet conditions moving in are expected to cause rapid snowmelt. Combine this snowmelt with as much as 10 inches of rain in the 24 hours (from Thursday evening to Friday evening), and the potential for widespread flooding is considerable, especially in the High Risk areas,” the Weather Prediction Center said.

Rainfall totals through Sunday morning could range from 1.5 to 3 inches for most urban areas with between 3 and 6 inches in the coast ranges and inland hills. Up 8 inches over the Santa Cruz Mountains and locally up to 12 inches over favored peaks and higher terrain of the Santa Lucia Mountains.”

The looming forecast led some ski resorts to announce closings. Kirkwood Mountain Resort said it would not open Friday, as did the Northstar California Resort and the Heavenly Resort in South Lake Tahoe, on Nevada’s border with central California.

Meanwhile, the Eastern Sierra Avalanche Center issued a backcountry avalanche warning for sections of Mono County, according to the National Weather Service in Reno, Nevada.

Elsewhere in the West, snowfall was occurring early Friday across parts of Nevada, Oregon and Idaho, where 6 to 12 inches of now are possible over lower elevations and 1 to 2 feet of snow are possible at higher elevations. This snowfall is expected to move into Utah, western Colorado and Montana by Friday morning, when up to 2 feet of snowfall are also possible.