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What are downbursts and are they dangerous?

Downbursts are powerful wind events caused by a strong downdraft within a thunderstorm. These strong winds then spread out quickly in all directions once they hit the ground.

By: Katie McGraw

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CLEVELAND — Downbursts are powerful wind events caused by a strong downdraft within a thunderstorm. These strong winds then spread out quickly in all directions once they hit the ground. Downbursts can cause quite a bit of damage and even be dangerous! In fact, they are often misinterpreted as tornadoes because the damage can be similar to an EF0 tornado (65-85 mph) or even an EF1 tornado (65-86 mph). From a distance, downbursts can even sometimes look similar to tornadoes! But they are completely different weather phenomena.

A downburst is a general term used to broadly describe both macro and microbursts. Microbursts simply refer to an especially small downburst that is less than two and a half miles across, while Macrobursts refer to a larger downburst, ultimately affecting more area/people/properties.

How do downbursts form?

In the initial stages of a growing thunderstorm, a powerful updraft dominates. As the cloud grows vertically, raindrops and hailstones start to form. Sometimes the updraft is so strong, it suspends a large amount of rain and hail inside the storm. Eventually, as the updraft weakens, the rain and hail inside the storm fall rapidly to the ground and will drag a lot of air along with it and speeding up as it moves toward the ground. When the downdraft hits the ground, much like a stream of water coming out of a faucet and hitting the sink, it spreads out rapidly in all directions and this is a downburst.

Fortunately, meteorologists' understanding of both the formation and the detection of downbursts has increased dramatically since an intense study of them began in the early 1980s. If it is felt that a storm will produce a damaging downburst, a Severe Thunderstorm Warning is issued. Normally a Tornado Warning is not issued, since a downburst is not a tornado. This is a great reminder to take Severe Thunderstorm Warnings just as seriously as Tornado Warnings!