Winter Fishing in Pac NW?

Winter vacation is approaching (somone said on Roff this week that the
academic calendar is nothing if not predictable), and basically I'm a bit
homesick and too full of Africa to look forward to a trek in Uganda or
another safari in South Africa. So I'm starting to think seriously of
charging my batteries with a quick visit to some familiar stomping grounds
to see friends and family.

When I left the US, I wasn't a flyfisherman, so I have no idea what the
winter season is like. If I spend from Dec 19- Jan 3 in the Seattle/Tacoma
and Portland regions, are there good fishing opportunities during that time?

--riverman