Dear Tom,
What is the difference between a "small tornado" and a "microburst"?
Paul Dunn, Bloomington, Ill.
Dear Paul,
A microburst is an area of strong and often damaging winds that occurs when rain-
chilled air, cooler and therefore heavier than its warmer surroundings,
surges down through a thunderstorm, then "splashes" violently outward when
it encounters the ground. By definition, a microburst affects an area less
than 2.5 miles in diameter.
Microburst winds, though limited in extent, can be strong. On June 29, 1990,
a microburst in Streamwood generated 150 m.p.h. winds that killed a person.
A tornado is a violently rotating column of air than extends from the base of a
thunderstorm down to the ground. The air within a tornado spirals upward in a
corkscrew fashion at speeds typically 100 to 300 m.p.h.
