A few weeks ago I went on a tour for a grad school. During our actual tour of the grounds, I stared as some repair men were fixing a set of windows. The windows were blown in...out...apart, however you want to describe it. This was on a part of the building that had several windows, but the other windows within a 30 foot radius were fine. Such a select piece of destruction seemed odd to me. I wondered, amused, "Did one of the students break under pressure and build a MacGyver-style bomb and let loose the frustration?"
Nope. Our tour guide noticed my attention and said the school had recently suffered a microburst. A What? So I asked for more of an explanation which amounted to the person fumbling and coming up with this: a reverse tornado. Hmm, probably not. I did find a great explanation of microbursts on the Department of Atmospheric Sciences of the University of Illinois.
Essentially, a microburst is a strong rush of wind towards the ground. If the "body" of the wind is less than 2.5 miles in diameter then it's a microburst and probably will cause damages to whatever is nearby. The highest wind speeds occur during the initial decent towards the ground, but then once contact with the ground has been made the wind fluidly bounces back to curl around the original column of wind and pockets of extreme winds are created. This explains how the windows on the grad school tour got shattered, and in such a freak manner.
The web page about mircobursts created by the U of Illinois has some good diagrams and actual photos of the occurrence, check it out here.
Happy fall weather everyone!