there are many sites online that give wave height and wind speed along with predictions. One is surfzone and another is
http://www.buoyweather.com. I call ahead to the harbor master to get there input along with reading a great book called "southern california cruising guide including offshore islands". This helps to show you which harbors are ok during windy days. I do know that you want to stay away from the west side of the island during the santa ana's.