What is a defining characteristic of microbursts in terms of duration and strength?

A defining characteristic of microbursts is that they seldom last longer than 15 minutes. Microbursts are intense, localized downdrafts which can occur during thunderstorms, typically characterized by their rapid onset and brief duration. This phenomenon involves strong downward winds that can produce significant turbulence, especially during takeoff and landing, making their short lifespan a critical factor for pilots and air traffic controllers to be aware of.

In contrast, the other options either describe durations that exceed those typical for microbursts or notate a level of sustainability in intensity that is inconsistent with their nature. The ephemeral quality of microbursts is vital in aviation safety, as their brief yet intense existence can lead to sudden and hazardous situations for aircraft in the vicinity.