A rare snow storm brought Oregon's largest city to a halt, with thousands of vehicles barely able to move on Portland streets and on one of its main highways.

Commuters began leaving work early on Wednesday, hoping to beat the storm.

But they quickly found themselves on streets that were clogged with traffic that was inching along on snow-slick streets.

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Traffic along the Interstate 5 and Interstate 84 interchange ramps are jammed after a snow storm moved in on the area in Portland, Oregon on Wednesday

People maneuver on slick roads on Wednesday. A wintry afternoon and evening is forecast for much of Oregon, with some cities expected to get a foot of snow

An emergency vehicle fights through heavy traffic during Wednesday's snow storm

A Portland street blanketed with snow is shown above. A school bus appeared to have rear-ended a parked car while passing through on the icy road

Cars fish-tailed, spun out, and collided. Motorists, some with their kids in their cars, who had made scant progress tried to keep their patience.

After more than three hours of waiting, some abandoned their vehicles and started walking.

Others hoped they wouldn't run out of gas.

Kimberly Wrolstad had been stuck on Interstate 5 heading to Tigard for about 90 minutes on Wednesday afternoon.

'It's frustrating,' she said. 'I don't know what's going on. I don't know if there are accidents. I know some of the trucks are having difficulties.'

Some drivers in Portland took to twitter to voice their frustrations about the clogged traffic.

'I've been stuck in snow traffic for over an hour & maps says it's going to take 2 more hours to get home,' Twitter user Cortney wrote on Wednesday amid the snow storm.

Bus riders, bundled against the cold, wait for the next ride. The city was ready to put city buses on snow routes, and had taken other precautions, but the suddenness of the storm caught many off guard

A bicyclist is surrounded by heavy traffic during Wednesday's wintry afternoon

Officials reported at least five vehicle crashes along a 21-mile stretch of Interstate 84, which runs through the scenic gorge

'I've been stuck in traffic trying to get home - 12mi from where I started, 6mi to go, but it's been 5hrs. I'm MISERABLE,' user Meg tweeted.

Another noted how they had been side swiped and rear-ended during snow traffic.

'Side swiped and rear-ended in a span of 5 minutes. It's a bit nutty out there PDX. Everyone stay safe & warm,' the user tweeted.

Portland does not use rock salt on its roads, for environmental reasons, and because snow is so rare.

The city was ready to put city buses on snow routes, and had taken other precautions, but the suddenness of the storm caught many off guard.

The Columbia River Gorge, just east of Portland, was getting hit hard.

Officials reported at least five vehicle crashes along a 21-mile stretch of Interstate 84, which runs through the scenic gorge.

Some drivers in Portland took to twitter to voice their frustrations about the clogged traffic

The accidents were between the towns of Hood River and The Dalles.

The National Weather Service has issued a winter storm warning for the gorge calling for up to eight inches of snow and gusting winds.

An avalanche plowed onto a main highway crossing the Cascade Range in Oregon, and then a second one occurred nearby, forcing closure of the road while snowplows cleared it, the Oregon State Police said on Twitter.

There were no injuries.

On the east side of the Cascades, up to 13 inches of snow were predicted for Bend, closing schools and other facilities.

Other parts of Oregon's eastern half were also expected to get a foot or so of snow.

Up to five inches of snow were expected in the Portland area by midnight.

A Memorial Middle School student grabs an icicle while preparing to head home from school on Wednesday in Albany, Oregon. Freezing rain in the Willamette Valley has cause several wrecks and canceled evening school activities

Icicles lengthen in freezing rain as they hang from branches on a maple tree in Eugene, Oregon on Wednesday

Jammed traffic pictured during the snow storm in Portland on Wednesday

Schools, government offices and other facilities were closed as the storm moved in.

The winter storm crept south up the Willamette Valley, the most populous part of Oregon, before reaching Portland, first hitting Eugene and then Salem.

Meanwhile in North Dakota, Minnesota and Wisconsin, people were under a wind chill advisory on Wednesday from the National Weather Service, as were parts of Montana, Wyoming, South Dakota, Iowa, Illinois, Indiana and Ohio.

Wednesday's highs ranged from 20 to 30 degrees below average in the northern U.S., according to the weather service.

The temperature was four below in Fargo, North Dakota, early Wednesday, and a daylight reprieve in the single digits was short-lived, with lows Thursday morning forecast to be around minus-12.

Duluth, Minnesota, was forecast for an overnight low of minus-five.

The National Weather Service has issued a winter storm warning for the gorge calling for up to eight inches of snow and gusting winds

An avalanche plowed onto a main highway crossing the Cascade Range in Oregon, and then a second one occurred nearby (one pictured above)

Cars travel on the icy roads. Portland does not use rock salt on its roads, for environmental reasons, and because snow is so rare

Other parts of Oregon's eastern half were also expected to get a foot or so of snow

With the arctic air tracking northeast, Connecticut Gov. Dannel P. Malloy said he would activate the state's severe cold-weather protocol on Thursday, calling for state police and other agencies to work with shelters and community groups to protect vulnerable residents.

Malloy also encouraged communities to open warming centers.

Vermont public safety officials warned residents to limit their time outdoors Thursday and Friday due to dangerous wind chills forecast at 35 below.

In upstate New York, some schools and government offices were closing early ahead of expected lake-effect snow expected to dump one to two feet.

Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said.

Temperatures in Portland were 28F on Wednesday night while in North Dakota they plunged to minus-7F

Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said

The system also is expected to bring widespread snow from the Great Lakes to the Northeast on Thursday.

Much of the central U.S. will be dry but cold.

Below-normal temperatures are expected this weekend and into Monday across the entire northern half of the country, from the Pacific Northwest to Maine and as far south as Oklahoma, Arkansas and Virginia, according to the Climate Prediction Center.

Up to half a foot of snow could fall from the Upper Mississippi Valley to the Northeast on Friday and Saturday, and areas east of the Appalachian Mountains could see freezing rain and sleet on Saturday.