Tom Moore, Lead Meteorologist, The Weather Channel
Dec. 20, 2008 6:31 am ET

West
By late today, the Pacific Northwest will be hit by a potent winter storm.

With very cold air in place, most of the precipitation will start as snow and last for awhile.

Meanwhile, lingering strong winds over eastern Montana will produce dangerously low wind chills through today.

Highs today will range from well below zero in Montana to the low to mid 60s across southernmost sections of California, Arizona and New Mexico.

By tonight, heavy snow will be falling across western Washington, including Seattle. Slowly rising snow levels across western Oregon will change the snow to rain or freezing rain at the lowest levels.

Snowfall exceeding one foot will fall in the mountains and around the Hood Canal.

Blizzard warnings are in effect, quite rare for this area. Look for significant snow and freezing rain along the Columbia Gorge, as well.

Look for wind gusts exceeding 60 mph at times in the Columbia Gorge.

Snow levels will rise across northern California as rain and mountains snow increases over the northern half of the state.

Snow will spread into the interior Northwest, as far east as the northern Rockies.

Monday will be wintry over a good chunk of the West with snow expected as far east as Montana, Wyoming, the mountains of Colorado and northern New Mexico while rain and mountain snow slides southward through California.