This ballistics program has a wind drift table that you can use. I was amazed at the way these big fat bullets are affected. The wind blows all the time here in Nebraska. I think it blows right through chetmarks yard right down into mine. Couple of days ago I was trying to dial my Triumph in at 150yds. The wind was blowing 15 mph+ and it caused the bullets to drift 6-7". Thats how I figured how fast the wind was blowing.
Zen

http://www.sav10ml.com/pages/load_data/traj_basic_dat.html