Being in WA like myself I would worry more about the Cascadia fault quake. I am out by Mt. Rainier so I have to worry about that also.
Worst thing in an EMP attack is the power grid going down. (source: Work for a power co.) There is only a few days worth of food in any store and about day 5 people will start losing their poop and keeping your stuff yours becomes a lot more important.
EDIT:
http://www.futurescience.com/emp/vehicles.html
some light reading about the subject.