We have been trying to predict the weather for a while now, and we've tried a lot of different forecasts. We think these are the best.
NOAA Marine Forecast
A marine forecast from NOAA, the national weather service. It is probably the most reliable wind forecast, but it tends towards the worst case scenario. Also, remember that wave hight is measured from center (the flat water level) to peak, not from trough to peak, so a 3 foot wave is 6 feet from top to bottom.
Live wind and temperature data from NOAA. The sensor is mounted on the Harrison-Dever Crib, where the city gets its water. Keep in mind that it's three miles off shore and 60 feet up off the lake surface, so the weather there probably isn't exactly the same as the weather here.
The Weather Underground
The Weather Underground, or wunderground.com, is probably the best general weather forecast. It gets its data both from the NOAA, and a network of local weather stations. It also has a great interactive radar.
Sailflow, and similarly featured iwindsurf.com, shows a network of wind stations, including the crib, and has pretty accurate spot wind forecasts. We use the Greenwood Beach station for the forecast.