Define a microburst and how long do they typically last?

• A. A violent localized downdraft that creates extreme wind shear (6000 fpm) at low altitudes and lasts up to 15 minutes
• B. A small rain shower lasting a few minutes
• C. A weather front that lasts hours
• D. A high-altitude wind event lasting 30 minutes

Answer: (A)

Microbursts are violent, localized downdrafts from a thunderstorm that reach the ground, creating strong, damaging winds over a small area. This downward rush brings extreme wind shear at low altitude, which is what makes microbursts so hazardous to aircraft during takeoff or landing. The dangerous winds and shear occur quickly and are brief—the most intense part lasts only seconds to a couple of minutes, with the overall event typically under about 15 minutes. The other options don’t fit because they describe phenomena without the same combination of a ground-reaching, concentrated downdraft and a very short duration.