A man rides a personal watercraft along a road flooded by the Skagit River on Monday in Sedro-Woolley, Wash. Associated Press/Elaine Thompson

BELLINGHAM, Wash. — Flooding and landsides prompted the complete closure of the West Coast’s main north-south highway overnight Monday near Bellingham, Washington, as the culmination of days of storms and high winds wreaked havoc in the Pacific Northwest.

The extreme weather was caused by an atmospheric river — a huge plume of moisture extending over the Pacific and into Washington and Oregon. More than 158,0000 customers were without power in Western Washington at one point Monday afternoon.

Interstate 5 was closed near Bellingham, just south of the Canadian border, because of the ongoing threat from debris and floodwaters.

Schools were also closed Monday. Evacuations were ordered in multiple areas as floodwaters swamped business districts and partially submerged cars in communities north of Seattle.

Forecasters said conditions should be much drier Tuesday. But the National Weather Service issued flood warnings for several rivers around Western Washington. Strong winds also hit the region Monday. Gusts pushed 60 mph in multiple places, including a gust of 58 mph at Seattle-Tacoma International Airport.

Late Monday, Gov. Jay Inslee declared a severe weather state of emergency in 14 Western Washington counties and said the state Emergency Management Division, with support from the Washington National Guard, would coordinate the response.

A state of emergency for the town of Hamilton was declared Sunday. People there, about 80 miles northeast of Seattle, were urged to evacuate.

Cars and trailers were packed into the parking lot outside the Red Cross evacuation site at Hamilton Baptist Church, where dozens of residents are waiting out the storm, the Skagit Valley Herald reported.

Skagit County officials were comparing this flood to severe flooding in 2009, when the Skagit and Samish rivers overflowed and caused damage to homes, farms and infrastructure,

As the water made its way down the Skagit River, people were warned to expect flooding in Sedro-Woolley, Burlington and Mount Vernon and Mount Vernon officials had recommended some evacuations late Monday.

Just south of the Canadian border in Sumas, Washington, officials said city hall was flooded and that the flooding event was looking like one not seen since 1990.

“At this point in time there is no reasonably safe way to drive to Bellingham without putting yourself or others at risk,” the city’s police department said via Twitter.

Nicole Postma, who owns a coffee stand in Sumas and is president of the Sumas Chamber of Commerce, told The Bellingham Herald Monday that people are nervous.

“We knew that the flood was imminent, but had no idea it would be like this,” she said.

Southwest of Sumas, deputies using a Whatcom County Sheriff’s Office rescue vehicle evacuated stranded residents in the Everson area, officials said on Twitter. One person was missing after being swept away by floodwaters and had been last seen holding on to a tree, Everson police said via Facebook.

Bellingham experienced record rainfall Sunday with a one-day total of 2.78 inches (7 centimeters), crushing the prior daily record from 1998 at 0.88 inches, according to the National Weather Service. A daily rainfall record was also set Monday in Bellingham with 1.89 inches.

All schools in the Bellingham, Washington, district were also closed Tuesday because of flooding, road closures and dangerous conditions, district officials said. Authorities said a person driving southbound on I-5 in Bellingham early Monday morning was seriously hurt when a tree fell on their vehicle.

Caylon Coomes of Bellingham drove his truck and paddle board from his home near Lake Whatcom earlier on Monday to flooded city streets near the interstate.

“It looked pretty good out there (by the lake), but the street looks a little bit better,” he said. He met another man in a parking lot and donning wetsuits they waded into the water and paddled away past vehicles stuck in the floodwaters.

On the Olympic Peninsula, several highways were closed in places, and the U.S. Coast Guard helped local authorities evacuate about 10 people west of Forks, Washington. Daily record rainfall also fell Monday west of Forks in Quillayute with 4.01 inches, the weather service said.

A semitrailer truck tipped in heavy winds on the Deception Pass bridge and was leaning on the railing Monday, state troopers said. The driver was able to get out, according to the state patrol.

Emergency officials warned that people should expect to see water in low-lying roadways and should turn around rather than drive through water on the road.