Pacific Northwest Snow

Bulk of the snow chances hits the Pacific Northwest overnight into Saturday

Published on November 18, 2011 9:30 am PT
– By TWS Senior Meteorologist
– Edited by Staff Editor

The Western U.S. is a tough spot to forecast for. Many news outlets five days ago (maybe even a week ago) called for a snow event in both Portland and Seattle, one of those being Accuweather. The thing about Accuweather is they never wait, they believe they can call an event and just ‘hope’ the model run was correct. They key here is to wait.( – A cold storm system is moving through the Pacific Northwest today, with the bulk of the cold air and moisture combined being tonight into Saturday across Tacoma.

Freezing levels seem to be hovering over 1,000 feet today across both Washington and Oregon with isolated flakes to 300 feet. During the overnight hours, a northeast wind will come into play for areas surrounding the county zones of Thurston and Pierce County.

What this will be doing is creating a convergence zone over both those counties. This will run with drier air in the lower levels to bring the snow level down below 300 feet by later tonight, into Saturday. This convergence zone will be an east to west orientating snow event, meaning it will not move up to Seattle, but stick over the two counties areas all night and into Saturday.

As for Portland, Oregon — the snow level will be around 1,000 feet overnight tonight into Saturday morning. There will be an offshore wind in this area as well but it is hard to say if snow will fall here. I’m going to say wet snow is possible, but nothing accumulating with the band that will move through overnight tonight and into Saturday morning.

Out of all the areas between Seattle and Portland, Tacoma, Washington will see the best chances of snowfall and Seattle coming in last for any chances. The main focus here is the convergence zone over KTCM.