There’s Nothing ‘Micro’ About a Microburst
In spite of the name, microbursts can cause extensive tornado-like damage.
On July 9, 2022 parts of Sudbury were extensively damaged by a severe thunderstorm. Rain, wind and hail battered the city in an event Environment Canada describes as a microburst.
Microburst falling and spreading out across ground. USA, 1980. Source: NOAA
I’ve always hated the term ‘microburst’. The word ‘micro’ seems to give it less significance. Like it is smaller, less damaging and less important than something like a tornado. The fact is that tornadoes and microbursts can have the same damaging effects and that microbursts may not be as small as we think.
So why call it a microburst to begin with? A microburst is a strong downdraft of wind that as it hits the ground spreads out, much like dropping a giant pail of water on the ground. Meteorologists call it a microburst when the area the initial downdraft covers is less that 4km wide. In fact, you can actually have a macroburst if the downdraft covers an area greater than 4km.
You may have heard of a tornado rated on the Fujita Scale. This system for measuring the strength of tornadoes based on damage was developed by Tetsuya Theodore Fujita, whose probably greatest contribution to meteorology was the discovery of microbursts or downbursts. During his studies in the mid 1970s most downburst winds (47%) fell into the category of F0 (64 to 116 km/h), about (32%) of the downbursts reached F1 category (117-180 km/h) and about 20% of the downburst cases reached or exceeded F2 intensity (181-253 km/h).
This used to be a 60 foot tall willow tree in New Sudbury - July 9, 2018. Source: Anne and Roger Pile
These winds are strong enough to tear roofs off of frame houses, demolish mobile homes, overturn boxcars and snap or uproot large trees.
Microbursts are not small! So don’t get confused by the term microburst. It can be quite a significant weather event. Unfortunately unlike the terms tornado, hurricane, or cyclone, it got the short end of the stick in the naming process.
What do you think we should call microbursts instead?
