Updated

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, 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.

Portland does not salt 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. 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 8 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 5 inches of snow were expected in the Portland area by midnight.

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.

Many Portland commuters left work early, hoping to beat the storm, but they were soon stuck in snarled traffic.

____

Associated Press writer Andrew Selsky contributed to this report.