Microburst

Synonym: downburst

Features of a microburst:

(1) it develops within a thunderstorm

(2) it is a localized downdraft that occurs when an updraft collapses (unable to sustain itself)

(3) the downdraft can have high wind speeds (over 100 mph)

(4) it can form a column <= 2.5 miles (4 kilometers) in diameter

Types:

(1) wet

(2) dry

Favorable conditions:

(1) high precipitatable water

(2) dry air in the mid levels with strong winds

The signature on Doppler radar is a mid-altitude radial convergence (MARC).

Exclusions:

(1) tornado

Damage may include:

(1) structural collapse

(2) airplane crash secondary to wind shear

(3) leveling of trees or vegetation