1/17/2012 Larry Costanzo | Category: Industry News | 357 Views | 0 Comments |

Ted S. Warren  /  AP

People in Seattle, Wash., on Sunday push a car uphill next to a bus showing an travel ad for skiing in Montana.

msnbc.com staff and news service reports

updated 2 hours 2 minutes ago

SEATTLE — A "potential major winter storm" that could dump twice Seattle's annual snowfall on the city over the course of two days was headed for the Pacific Northwest on Tuesday night and into Wednesday, weather.com reported.

Chris Dolce, a meteorologist with weather.com, wrote that travel could become "dangerous or impossible" by Tuesday night in areas including Seattle, Olympia, Bellingham as well as Portland, Ore.

Weather.com was predicting that parts of the Seattle area could be hit with 12-18 inches of snow in the next 48 hours. Up to 8 inches was also expected in Portland.

"Keep in mind, average annual snowfall is only 2.4 inches in Portland and 5.9 inches in Seattle, so these amounts are very significant for these metro areas," Dolce added. "According to the National Weather Service in Seattle, Wash., snow amounts from this storm could exceed anything seen since November 1985 at Sea-Tac airport."

The Seattle area saw several inches of snow over the weekend, and then a lull on Monday and overnight into Tuesday morning for most of the region.

Dolce said that "several feet of snow" was expected to pile up in the Cascade and Bitterroots mountains.

Interstate 90 at Snoqualmie Pass in the Cascades was shut down Tuesday morning for avalanche control.

PhotoBlog: Snowy in Seattle — Winter storm snarls traffic

According to Dolce's forecast, snow was likely to spread well inland across the interior Northwest into the Northern Rockies. Spokane, Wash., Coeur d'Alene, Idaho, Kalispell, Mont. and Missoula, Mont., will all deal with substantial amounts of snow and rough travel conditions, weather.com reported.

"There is a chance that an area of localized heavier snow could develop in the Seattle metro area Monday night into Tuesday morning along the arctic frontal boundary," Dolce added.

Snow was also forecast in the Midwest and New England starting later Tuesday, weather.com reported.