Atmospheric River Moving Over Washington and British Columbia

The winter storm season will kick into high gear heading into the weekend for the Pacific Northwest. Here is a look at the soggy and chilly forecast for this corner of the country.

Atmospheric River Set Up to Douse the Northwest

The first atmospheric river of the winter season is forecast to set up over Washington state and up into British Columbia, Canada this weekend. The impacts of this potent system will range from heavy rain, flash flooding, and even a bit of potential snowfall.

The plume of moisture originating in the Pacific Ocean will funnel into the northwestern corner of Washington and the southern tier of British Columbia. As is typical with these plumes, it will work as a massive firehouse dousing the region with persistent moisture. The metropolitan area of Vancouver, British Columbia will bear the brunt of the impacts, however, cities such as Bellingham and Seattle will also pick up meaningful moisture out of this weather maker.

The storm will first send the moisture flying on Friday. How wet will it get? The forecast is calling for rainfall ranging between 5 and 10 inches for the west-facing slopes of Vancouver Island in Canada. Widespread rainfall amounts of 4 to 8 inches are in the forecast for the western slopes of the Olympics in Washington and the lower slopes across British Columbia's Coastal Range. A maximum accumulation of 14 inches is possible for the hardest-hit areas through the weekend.

Rainfall amounts may eclipse 2 inches per hour during the height of the activity. Water coming down this hard this fast can easily overwhelm storm drains. Flooding could become an issue in areas where leaves have already fallen from the trees and are clogging drains. The hilly terrain of this region will see the threat of rock and mudslides as a result of the heavy rain roaring down the slopes.