One of the tremendous pluses of the uses of radar is the ability for it to determine the speed (relative to the radar's fixed position) of objects (primarily think of cloud/rain droplets) in the air.
Within this post, I'll be addressing a weird warm-up experienced during the early morning of June 29th, 2012 across the Foothills in Northwest NC. I will also mention some key things regarding the extremely destructive and powerful thunderstorm complex / wind-event (derecho) that marched across a large swath over the Midwest and Mid-Atlantic States