For winter sports, you’ll head to Mt Hood, about an hour and a half drive from Portland.
There are two Resorts on the mountain: Timberline and Meadows. Both are open to both skiing and snowboarding.
Timberline has a beautiful lodge and is a touch closer to Portland. Meadows has a larger ski area.
Often the weather is different on the two faces of the mountain, so the weather/snow at any given time is often helpful in choosing which to visit.
Snowshoeing is also available. Here’s the List of trails.