Actually its all to do with the effect of changing groundpeed and angles of bank caused by the prevailing wind velocity at height with respect to the radar CFAR circuits and the orientation to the working areas.
Not that you would expect one of the pilots to understand that.... When this used to be taught to the new Sentry crews in the days of yore, the pilot instructor on Sentry Training Squadron refused to send his students because "we have already studied met at basic flying training". Sad but true!