Courtney's Cloud Corner: Microbursts

Microbursts or downbursts are an area of intense high wind downdrafts that can produce damaging effects. The beginning part of the name is “micro-” because of the relatively small area it covers.  According to the National Weather Service, a microburst can cover an area of around 2.5 miles with the potential of having wind speeds of 100 mph or more within a short period of time. Usually microbursts develop through the updraft and downdraft with a cumulonimbus cloud.

During a wet microburst, the updrafts suspend the precipitation in the upper portion of the cloud. Dry air will mix within and cause it to evaporate. As evaporation is a cooling process, the precipitation will cool, become dense, and fall. This process is called dry entrainment with evaporating cooling. Wet microbursts can also be formed by water loading, which is when the weight of the falling rain encourages the dry air to sink. This is just one of the microbursts to discuss.

Another type of microbursts is dry microbursts. Dry microbursts are similar to wet microburst, as they both deal with downdrafts and strong winds, but it usually does not involve falling precipitation. As the downdraft occurs within the cumulonimbus cloud, the precipitation falling will evaporate. This will not stop the high winds from occurring because there is still a downdraft. Even though microbursts are fascinating to perceive, it is strongly encouraged to move into a sturdy shelter away from windows.