hi Optrixs;
Actually the wind at the muzzle will cause more deflection problems, but all have to be accounted for in your calculations. The Kestrel is a good instrument for you muzzle windage, best set up is on a small light tripod like a camera table top. For down range look at mid then target wind and adjust for an average. Also be aware that at longer ranges your bullet will be slowing down as it slows it becomes more prone to wind deflection.
The best way to learn is to get yourself a good manual such as FM 23-10, "The Ultimate Sniper" By Maj. John Plaster, Trigger50's book "The Complete .50 caliber Sniper Course" has a lot of good info on the subject, though geared to the heavy sniper rifle it applies to medium SWS. Once armed with a good manual take your spotting scope out to a field and learn to read the wind. After you have a handle on it then go to the range with your wind meter, spotting scope and a LOG BOOK for your rifle. Go on what others call bad days, estimate your windage and take the shot. RECORD the info in your LOG BOOK along with corrections made. This way you will learn your mistakes, what corrected it and get to know your rifle too. The log book will be exc. reference for all your field shooting. To make it interesting go to a area where you can fire at extended ranges with hilly/varying terrain, after seeing how the wind behaves in mixed terrain you to will have gray hair
Take care...Jim