Microburst facts for kids

A microburst is like a very strong, focused burst of wind that rushes down from a thunderstorm. Imagine a giant, invisible column of air suddenly crashing down from the sky! When this air hits the ground, it spreads out in all directions, causing powerful, damaging winds. Microbursts are very different from tornadoes, which have spinning winds. Instead, microbursts have straight-line winds that push outwards from a central point. They can be very dangerous, especially for airplanes taking off or landing.

What is a Microburst?

A microburst is a powerful downdraft, which means air moving downwards, that comes from a thunderstorm. It's like a small, intense "explosion" of wind hitting the ground. These winds can be as strong as those found in a weak tornado, sometimes reaching over 100 miles per hour (160 kilometers per hour)!

How Do Microbursts Form?

Microbursts form when a lot of cold, heavy air inside a thunderstorm suddenly drops to the ground. This happens because:

• Rain or hail: As rain or hail falls through dry air below the storm, it evaporates or melts. This process cools the air around it, making it heavier.
• Heavy air sinks: This colder, heavier air then sinks very quickly towards the ground.
• Impact and spread: When this fast-moving air hits the ground, it has nowhere to go but out! It spreads out in all directions, creating a burst of strong, straight-line winds.

Wet vs. Dry Microbursts

There are two main types of microbursts:

• Wet Microbursts: These are the most common type. You can usually see them because they bring heavy rain with the strong winds. It looks like a sudden, intense downpour.
• Dry Microbursts: These are harder to spot because they don't have much rain reaching the ground. The rain evaporates before it hits the surface, but the cold air still rushes down and causes strong winds. Sometimes, you might see a "dust ring" on the ground as the winds kick up dirt.

How Powerful Are Microbursts?

Microbursts can cause a lot of damage, similar to what a tornado might do.

• Wind Speeds: The winds in a microburst can reach speeds of 60 to over 100 miles per hour (97 to 160 km/h). In extreme cases, they can even exceed 150 mph (240 km/h)!
• Damage: Because the winds spread out in a straight line, they often cause damage that looks like a giant fan. Trees might be knocked down in one direction, and then in another direction further away. They can flatten crops, damage buildings, and even flip over large vehicles or shipping containers.

Why Are Microbursts Dangerous?

Microbursts are a serious danger, especially for airplanes.

• Wind Shear: The sudden change in wind speed and direction over a short distance is called "wind shear." For an airplane, flying into a microburst means it might suddenly lose lift as the wind changes from a headwind (pushing it forward) to a downdraft (pushing it down) and then a tailwind (slowing it down).
• Aircraft Safety: This sudden change can make it very difficult for pilots to control the aircraft, especially during takeoff or landing when they are close to the ground. Modern airports use special radar systems to detect microbursts and warn pilots.

Detecting Microbursts

Meteorologists (weather scientists) use several tools to detect microbursts:

• Doppler Radar: This type of radar can see not only where rain is falling but also how fast the rain droplets are moving towards or away from the radar. This helps them spot the strong downdrafts and spreading winds of a microburst.
• Weather Stations: Ground-based weather stations can measure sudden changes in wind speed and direction.
• Pilot Reports: Pilots who experience microbursts can report them, helping to warn other aircraft.

Images for kids

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  Illustration of a microburst. The air moves in a downward motion until the surface. It then spreads outward in all directions. The wind regime in a microburst is opposite to that of a tornado.

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  Downburst damages in a straight line. (Source NOAA)

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  Dry microburst schematic

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  A wet microburst

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  A series of photographs of the surface curl soon after a microburst impacted the surface

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  Strong microburst winds flip a several-ton shipping container up the side of a hill, Vaughan, Ontario, Canada

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  Downburst on a weather radar.

See also

In Spanish: Reventón (meteorología) para niños