What jmez said!!! I’ve started to think of wind as “macro” and “micro”. Your macro-winds are thermals and prevailing, but within the macro-winds, you can have spots of sun and shade, small rises and depressions, and terrain features that cause winds to swirl or shift directions 180 degrees. These micro shifts and swirls are localized. The prevailing wind may be uphill, but perhaps you are in a small depression or patch of cool timber pulling your scent downhill for 50 yards before it swirls and the prevailing thermal moves it back uphill. Generally these micro areas are only a factor inside of 100 yards. What jmez said is spot on. It is fairly easy to predict and play the macro level wind, but inside 100 yards it is very tough to not get winded within a couple of minutes unless the prevailing wind or thermals are pretty strong.