Sean, thats a good question, this is the only place I have to shoot long range and I am sure the turbulance caused from the wind flowing around the trees and builds causes some very inconsistent gusts. I suppose that could explain alot of it, the wind moving in from the right has to flow through a line of spruce trees, where as coming in from the left there is the house and two garages plus a bunch of trees. Its probably very likely the wind coming off the roofs creates a down draft? and thats where I see the massive elevation changes.