What characteristics define a macroburst?

A macroburst is characterized as a convective downdraft that has a significant diameter, specifically at least 2.5 miles wide. This feature is essential because macrobursts can produce severe and damaging winds. The significance in the size translates to the potential for intense and widespread damage. The descending air within a macroburst can spread out rapidly upon reaching the ground, resulting in strong outflow winds that can lead to hazardous conditions for aircraft, particularly during takeoff and landing phases.

The other choices do not accurately represent the defining characteristics of a macroburst. For instance, a downdraft with a diameter of less than 1 mile describes a microburst instead, indicating a much smaller scale and typically less severe impact. Unpredictable gusts and rapid changes in wind direction, while associated with severe weather phenomena, do not provide the specific defining measurement (in terms of size) that distinguishes a macroburst from other types of downdrafts.