The 2nd train between Seattle and Vancouver BC is now operating and both sections of the train are extended to serve Portland. There are now 2 daily trips between Seattle and Vancouver and 4 daily Cascades trips between Seattle and Portland.
Southbound service (Train 517) leaves Vancouver at 635am, arrives in Seattle at 1100am, departs for Portland at 1130am, arrives in Portland at 255pm.
Northbound service (Train 518) leaves Portland at 305pm, arrives in Seattle at 630pm, leaves Seattle at 700pm, arrives in Vancouver at 1100pm.
If anyone is wondering about the 10 minutes between 517's arrival and 518's departure, I'm sure that 2 different trainsets will cover the trips. The next Cascades expansion will have a NB departure from Portland at about 530pm and another SB departure from Seattle at about 600pm.