In 1977 I took a trip to Phillips, Wi to hunt beer cans. As I approached Phillips I noticed that the trees in the entire area were lierally flatttened. I had never and have never seen anything close to that scene I asked the area folks what had happened and they told me a wind came through the area earler, on July 4th and leveled the entire forests in the area for about 5 by 14 miles with that area as epicenter.
At the time little was known about downblasts of that sort. .
http://www.crh.noaa.gov/grb/events/070477.php