I'm less concerned about tidle swing, but generally speaking I don't like to fish when the wind is greater than 20 mph.

I believe Slabquest posted this site in the past which I have found very useful. It basically tells you the wind speed and direction in knots for various places on the PS. If you go to "More WA Winds" you can see what the ferries are recording as they make their crossing.

http://www.nwboating.com/wx/w/wwa_wind