http://wsdotblog.blogspot.com/2015/12/heavy-rain-high-winds-and-snow-on-its.htmlThe closures on US12 around White Pass seem to be the most serious, since they involve washouts on shelf road.
The main US2 closures are in Tumwater Canyon, so there is the Chumstick detour for cars.
The I5 closure is between Portland and Vancouver. There are detours but they can't handle a lot of traffic. When I looked last night, US30 on the Oregon side of the river also had closures. Freight traffic was being directed up the east side of the Cascades.
There were other closures in NW Oregon.