What causes a downburst?

The downbursts form when falling raindrops pass through drier air en route to the ground; if this air is dry enough, then water can evaporate from the rain drops as they fall. This evaporation cools the air (similar to the cooling you feel when you step out of the shower or bath).

What is a downburst and what causes it?

Downbursts are powerful winds that descend from a thunderstorm and spread out quickly once they hit the ground. These winds can easily cause damage similar to that of a EF0 (65-85mph winds) or even EF1 (86-110mph winds) tornado, and are sometimes misinterpreted as tornadoes.

Where do downburst occur?

Dry microbursts are most common in the western United States and over the High Plains where cloud bases are commonly as high as 500 mb with predominantly dry layers existing below (Wakimoto 1985).

What is the difference between a downburst and a microburst?

Downburst is the general term for all localized strong wind events that are caused by a strong downdraft within a thunderstorm, while microburst simply refers to an especially small downburst that is less than 4 km across. A gust front is the leading edge of rain-cooled air that clashes with warmer thunderstorm inflow.

What happens during a downburst?

A Downburst is created by an area of significantly rain-cooled, descending air that, after hitting ground level, spreads out in all directions producing strong winds.

Weather 101: What is a downburst?

Where do Derechos most commonly form?

They are impressive to see both on the ground and from the sky. Derechos are most common in the Midwestern United States, but are still fairly rare. You might see a derecho about once a year there. They can occasionally be found all the way up into the Northeast.

Is a microburst worse than a tornado?

Although microbursts are not as widely recognized as tornadoes, they can cause comparable, and in some cases, worse damage than some tornadoes produce. In fact, wind speeds as high as 150 mph are possible in extreme microburst cases.

Is a derecho a downburst?

Derechos are straight-line winds associated with a downburst. They blow out in front of the squall line and are the strongest winds created by the downburst. This happens because the movement of the storms is already in that direction. Derechos can be as large as 200 miles wide and 1,000 miles long.

Is a downburst a tornado?

While the rotating winds of a tornado converge at the surface then rise up into the storm, often resulting in narrow paths of chaotic damage, downburst winds descend and diverge beneath the storm and result in outward burst patterns of damage or wide areas with damage mostly from the same direction.

What does a downburst look like on radar?

In other words, a downburst will appear as a circular area that is half red (which denotes air moving away from the radar) and half green (which denotes air moving towards the radar).

How long can a microburst last?

As the name suggests, a microburst is a relatively small weather event, lasting anywhere from a few seconds to several minutes and affecting 2.5 miles or less.

How is a microburst created?

Microbursts happen when dry air begins to mix in with the ongoing precipitation in a thunderstorm, forcing droplets in the cloud to evaporate. This evaporation causes a rapid drop in temperature, commonly referred to as evaporative cooling.

How can you tell a microburst?

Microbursts can be identified by locating areas of convergence above the ground. When air converges above the ground, the air below will sink. Convergence can be detected on velocity products by looking for velocities from different directions that slow as they approach each other.

How does a derecho form?

Typically, a derecho forms from a cluster of thunderstorms that organize into a bow shaped complex known as a bow echo. When the storms are guided by strong, unidirectional, winds and forced into warm and humid air, the storm rapidly intensifies.

What is a rain bomb?

A rain bomb is a colloquial name for what meteorologists refer to as a wet microburst. When rain from a thunderstorm evaporates before reaching the ground, it's called a microburst. As the air accelerates toward the earth owing to cooling, it cools rapidly. A downdraft is a name for this strong wind.

What are mini tornadoes called?

A common wind phenomenon that occurs throughout much of the world, including Arizona, are dust devils. An example of a dust devil can be seen to the left. These dust-filled vortices, created by strong surface heating, are generally smaller and less intense than a tornado.

How is a downburst different from a tornado?

The major difference between what we see on the ground from a downburst and a tornado is that the winds from a tornado suck things inward and the winds from a downburst push outwards.

Are downbursts rare?

Downbursts can produce damage similar to a tornado, and are quite common across the western Carolinas and northeast Georgia.

What causes downdraft thunderstorms?

The precipitation falls into the updraft. The falling particles drag air down with them. This sinking air is referred to as downdrafts. Entrainment into the downdraft results in some evaporation of the precipitation, which causes a cooling which makes the air more dense, thus increasing the downdraft.

How often do derechos happen?

The occurrence of derechos is divided into two seasons; the "warm" season which is May, June, July and August. 70% of all derechos occur during these four months. The remaining eight month comprise the "cool" season. Percent occurrences of derechos by month.

What was the worst derecho ever?

The June 2012 Mid-Atlantic and Midwest derecho was one of the deadliest and most destructive fast-moving severe thunderstorm complexes in North American history.

When was the last derecho in the US?

aka "Heartland Derecho", A severe weather event which took place from August 10–11, 2020 across the Midwestern United States and portions of southwestern Ontario.

How often do microbursts occur?

Quite often, wind damage produced from a thunderstorm is from a common phenomenon called a microburst. According to the National Weather Service, there are approximately 10 microburst reports for every one tornado, but these numbers are an estimate.

Do microbursts make noise?

WMUR- TV reports both microbursts and tornados can have similar wind speeds and sound like a train barreling down from the sky.

What is a reverse tornado called?

A microburst is basically a tornado in reverse, according to descriptions by the Weather Channel. They have two important similarities: They both generate destructive winds, and they make for indisputably great photos. But while a tornado funnels wind in and up, a microburst's wind is funneled down and out.