Around 4,000 people were ordered to evacuate from a town about 60 miles north of San Francisco Tuesday night, as heavy rain and snow is expected to raise a river to flood levels not seen since 1995, The Sacramento Bee reported.

"Evacuate now if you live near the Russian River," the Sonoma County Sheriff's Office urged, according to AccuWeather.

The Russia River in Guerneville had already reached 32 feet by 6 p.m. Tuesday and is expected to hit 46 feet by Wednesday evening, The Sacramento Bee reported.

"If it gets to 46 feet, it's done. There is no way to prepare for that," the manager of the one-story River Inn Grill Andre Vazquez told The Sacramento Bee. He said the restaurant would be submerged if water levels reached that point.

The flooding comes due to a wet, slow weather event called an atmospheric river storm, The Mercury News reported.

"It's pretty serious," Sacramento National Weather Service (NWS) hydrologist Peter Fickenscher told The Mercury News. "We consider this a major flood. There will be numerous impacts. It's a rare event. The rainfall has been very focused and concentrated right through the Russian River basin. It has been non-stop rain for 24 hours and it will continue overnight into Wednesday."

In addition to Guerneville, evacuations had been ordered in Mendocino County in the Ukiah Valley and Hopland areas, where the Russia River was expected to begin flooding low elevations by 7 p.m. Tuesday and reach its highest levels by 1 a.m. Wednesday.

Evacuations were made more difficult by a mudslide on Bohemian Highway near Monte Rio, Accuweather reported.

A man and woman were trapped in the slide but were rescued, according to The Sacramento Bee.

"Well I fell into the mud when the tree fell over the top of me. It happened so fast you don't even know, you know?" survivor Kear Koch told KGO-TV, as The Sacramento Bee reported.

The rain came from a weather system that moved off the Pacific from Hawaii and has caused power outages and taken down trees across the West, adding to a winter that has seen record precipitation in the Western U.S. The city of Santa Rosa received a record 5.66 inches of rain, the most since 1902.

A study released last year found that California could expect more extreme weather due to climate change, with both longer droughts and increased flooding as precipitation falls in heavy bursts.

"I feel like I'm living in a perpetual state of disaster here in California," journalist Kent Porter tweeted Wednesday.

Evacuations were also ordered in Butte County, according to KRCR News, which was devastated by the Camp Fire last fall.