We're looking at multiple types of impacts across the area Wednesday night through Friday night this week - heavy rain, heavy snow, ice, and wind.
We're expecting a narrow band (~50-100 miles wide) of constant, heavy rain to develop starting late Thursday afternoon or Thursday evening, probably over the N Oregon or S Washington coast. The latest thinking is the band will push south on Friday. Our latest thoughts on totals: 
Because we don't know exactly where the heavy band of rain will develop and how fast or slow it will move, we can't say at this point exactly what cities or rivers may see flooding. Stay tuned to weather.gov/portland for more details as we get closer to the event.
Snow levels will start out ~3000 ft in the Cascades Wednesday, but snow levels rise through the event. The heaviest snow is expected above ~4500 ft. The Cascade passes will see snow Wednesday thru Thursday, but it should switch over to rain at the passes by around sunset Thurs.
As snow levels rise, we expect some cold air to get trapped in the Upper Hood River Valley and valleys in the N Oregon Cascades ~2500-3500 ft, with freezing rain falling and ice accumulating. This includes Hwy 22 from Marion Forks to Hwy 20 & Hwy 35 from ~ Parkdale to Odell.
We expect pretty much everybody from the Cascades west will notice winds pick up out of the south or southwest late Thursday afternoon through Friday morning. Right now we don't expect the winds to have much impact, but we can't rule out a couple of trees falling.
In icy areas in the Northern Oregon Cascades (see a couple of tweets earlier in this thread), wind will make the ice impacts worse by making trees more likely to fall. The Upper Hood River Valley shouldn't see as much wind.
