In October 1859, the U.S. military arsenal at Harpers Ferry was the target of an assault by an armed band of abolitionists led by John Brown (1800-59).
A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Some tornadoes are clearly visible, while rain or nearby low-hanging clouds obscure others.t is not uncommon to see clear, sunlit skies behind a tornado. 1  Tornadoes cause an average of 70 fatalities and 1,500 injuries in the U.S. each year. 2  The strongest tornadoes have rotating winds of more than 250 mph.
Because: Nobody knows the true wind speeds at ground level in most tornadoes, and The amount of wind needed to do similar-looking damage can vary greatly, even from block to block or building to building, ...damage rating is (at best) an exercise in educated guessing.