Have been using this site for the summer, lots of info and the forecasts have been fairly accurate. Hope I am not re-posting old info but here is the link...
http://www.windfinder.com/
Enjoy!
I use their iPhone/iPad app which is excellent. There is a free version downloadable at the Apple App Store, and a "pro" version that costs a few bucks, has some extra features and doesn't have the pop-up ads.
Wes
Here's another one that may interest people:
http://windmapper.com/