From Amtrak Cascades on Facebook:
One of the volunteers at Olympia/Lacey station reports:Train 500 is at Centralia and 501 will reverse to Tacoma. ...Some buses are available. Unfortunately, we will not be stopping at Tukwila, Olympia, Centralia or Kelso to avoid getting stuck on side roads. Due to road conditions it is likely to take substantially longer to travel I-5 between Seattle and Portland. We appreciate your patience.
Between fallen trees and frozen switches-NO AMTRAK SERVICE.