Microburst

What is a microburst? A microburst is a column of wind that can have speeds from 40 to 60 mph. These columns often stretch up to 10,000 feet in the air and typically last for less than five minutes.

The term "microburst" was first coined by a scientist named C. F. Rammel in 1969 to describe a small downdraft that contained very high winds that were affecting flight patterns of aircrafts landing at an airport in Phoenix, Arizona. Microbursts typically result from a thunderstorm system and can be monitored using radar technology to detect signatures, especially when they happen before the onset of precipitation or after the cessation of precipitation 

These characteristics have been seen in a number of locations throughout the world, including western Canada, Scotland, Texas, New Zealand, and most recently, the United States. In July 1999, a microburst touched down near the Kansas-Oklahoma border as thunderstorms were passing through the region. The microburst was described as lasting from 10 to 15 minutes and extending up to 10 miles from its center. 

On July 25th, 1999, a microburst developed over the Hudson Bay in Manitoba, Canada. The wind gusts associated with this microburst reached 80 mph. This column of wind traveled over 1,500 feet above the surface of the water. A similar event happened seven months earlier when a series of four microbursts were reported by an air carrier flying into Helena Montana. The first one lasted about two minutes and had winds estimated at 60 mph to 70 mph approaching the plane from its left side.

Needless to say, this is very dangerous to aircrafts flying through the area. A microburst is often mistaken by pilots of small aircraft or of airliners for an updraft or tailwind. They adjust their altitudes downwards in response, but instead of getting a tailwind, they get slammed with very strong winds approaching at an angle (and above) them.

The result is that the plane can encounter turbulence that may be more powerful than what it might normally handle at that altitude on a regular basis. There are also instances where planes were struck by wind shear (a change in wind speed and/or direction over a short distance). These events often result in some serious damage to the plane, specifically, to its wings or engines.

Microbursts have even been blamed for missing planes in the Bermuda Triangle. In July 2001, a 737 from the United States Air Force was reported missing over the Bermuda Triangle. Shortly after takeoff from Grand Turk Island, there was a sudden drop in air pressure which caused a loss of cabin pressure and loss of engine thrust. The plane then dropped from an altitude of 4oo ft at a descent of around 3000 ft per minute. A series of microbursts were reported to have been directly associated with these events. The airplane was found 400 miles off the coast of Florida in 2000.

Such occurrences sound very unusual and unexplainable by conventional meteorological phenomena, especially since there were many planes flying normally in the area at the time this event occurred. But if one looks at the characteristics of microbursts, this event makes perfect sense. 

Microbursts are associated with thunderstorms. A thunderstorm is a very unstable event that has all kinds of updrafts and downdrafts of air traveling in many different directions. It is not uncommon to have different types of winds within a single thunderstorm. So being able to have wind speeds reach upwards of 70 mph traveling upward, while winds on the ground are calm, is not at all uncommon for these events. When this type of column of wind meets an airplane traveling through it, it will slam into it rapidly changing the direction and speed of the wind blowing over the wings.