“Microbursts” Very Different than Tornadoes
Saturday’s storm seemed to have a textbook example of what meteorologists call a “microburst” — a form of downburst that sometimes forms from thunderstorms, and which can cause extensive straight-line wind damage over small areas.
Downbursts do not have rotating winds like a tornado. They start when hail or large raindrops fall through drier air. As hailstones melt and the drops evaporate, the air is cooled. Because cold air falls relative to hotter air, this process creates a column of air that spreads out when it hits the ground. A “microburst,” which generally lasts only a few minutes, rapidly loses strength. However, areas near where the cold air falls can experience heavy and sometimes damaging winds.