If understand correctly, you should be able to key the wind direction and the magnitude in the attribute editor (RMB > key selected). If you want instant change, you only need to set the original key at the start frame, and the new values where you want the change to take place, then importantly, change the tangents (in the graph editor) to stepped. Hope that helps. Let me know if I misunderstood the question.
Well I thought I tried that. Is it just put the direction where I want it to start, they say on frame 50 I would just change the direction and use s to keyframe again? I thought I did that but I didn't do the second part with the graph. Could you go into more detail with that?