Thanks for the responses. I used to use forecast.weather.gov, but it doesn't have wind speed that I could find, and the format is really annoying to work with. My reading of the NWS site made me think that the old API was being retired, and that the new one was ready to go. I also investigated DarkSky, but I found their forecasts to be wildly inaccurate for the mountainous areas my app needs.
The new API would be great if it just weren't so slow. If someone could put me in contact with the NWS technical team I'd be happy to do what I can to help speed it up.