While snow levels by Thursday will be between 7 and 8,000 feet, cold air comes crashing into Western Washington by late Friday and early Saturday, quickly dropping snow levels to below 3,000 feet and Snoqualmie Pass.

And the colder and snowier forecast in the high country will continue to be reinforced by succeeding cold fronts building up accumulations of the white stuff of well over a foot in some spots by the middle of next week.  High elevations on west or northwest facing slopes could pick up even more!

While lowland snow is very unlikely, it'll be breezy, chilly and quite wet around Seattle and the Sound and at the coast from Saturday through at least Tuesday!

Exact amounts of snow in the passes can't be determined as yet, but travelers beginning Saturday should stay abreast of road conditions because heavy snow squalls can cause roads to become treacherous, if at least temporarily.  The most likely times for travel issues through Snoqualmie Pass look like Saturday morning and again on Monday.  

However, we are several days out from this event, and timing is likely to change somewhat.

Historic Alaska storm to give energy to our weekend weather

The long-range overall weather pattern indicates a major storm in the Bering Sea between Russia and Alaska will dive south along the western Canada coast and be the catalyst for this major change in our weather beginning this weekend.

The storm is projected to be one of the worst on record for Alaska, a true "superstorm" and cause storm surge in western Alaska, including Nome, accompanied by wind gusts of over 90 mph!  

Normally, the western Alaska coast would be protected from ocean surge by sea ice, but it's too early in the season for that to be a protective buffer.  Significant damage is likely there.

Lowland snow unlikely

As the storm gets driven south through Alaska, it loses a lot of its energy, but the trajectory will drag cold air both at the surface and aloft into the Pacific Northwest.

Depending which forecast model is to be believed, Idaho could get the brunt of the wintry weather in the mountains with lowland rainfall.  However, the often-more-reliable ECMWF (often referred to as the "European model") has a storm track which is nearly optimal for our mountains to pick up some big-time snow.

While the first blast will drop snow levels to as low as 2,000 feet this weekend, successive cold fronts will be mild by comparison and have more of a maritime composition off the north Pacific.  

This bodes well for chilly rainfall, but not snow, in the lowlands.

We'll also likely see some gusty winds at the stormiest times, especially near Puget Sound, the Strait of Juan de Fuca and along the Pacific coast.

Long-range indications point toward breaking out of the heart of the chill and damp by Wednesday of next week.

However, that is an uncertain long-range prediction.

The take-away is that you should prepare to bundle up and get the rain boots ready in the lowlands, and keep very close track of traffic and weather if traveling in or through the mountains and passes beginning this weekend!