Definition
A small-scale, intense downdraft that descends from a thunderstorm or rain shower and spreads outward in all directions when it strikes the ground, producing severe wind shear. A microburst typically affects an area less than 2.5 miles across, lasts only 5 to 15 minutes, and can produce downdrafts exceeding 6,000 feet per minute and horizontal wind changes of 45 knots or more across the affected area.
Plain English
A short, violent column of air that crashes straight down out of a storm and then blasts outward along the ground, creating sudden and dangerous wind changes for any aircraft flying through it.
Context Anchor
Seen in weather, thunderstorm, takeoff, landing, and wind-shear discussions.
Derivation
From 'micro' (small) and 'burst' (a sudden, violent outpouring). The term highlights that this is a small-area event compared to the parent storm, but extremely violent within that area. The 'burst' part captures the way the air slams down and explodes outward across the ground.
Why Pilots Care
Creates severe wind shear that can cause abrupt loss of airspeed and altitude during takeoff and landing.
Analogy
Imagine pouring a bucket of water straight down onto a flat floor. The water hits the floor and spreads out hard in every direction. A microburst is air doing the same thing — falling straight down, then blasting outward along the ground.
Grounding Statement
Picture a column of air dropping out of a storm, striking the ground, and spreading outward like water from a bucket dumped onto a floor.
Intuition Check
Do not let “micro” make it sound harmless. A microburst is small in size, but it can be powerful enough to make takeoff or landing unsafe.
Example Sentence 1
The crew delayed departure after the tower reported a microburst alert near the approach end of the runway.
Example Sentence 2
Pilots watch for rapidly developing rain showers because they can hide microbursts until the aircraft is already committed to land.