Based on radar analysis and ground survey, it was determined that the damage in Ada from Monday’s storms was caused by a microburst and not a tornado. Many of you have been wondering what a microburst is and why there are not “microburst warnings.” So, I figured I would explain this.
A thunderstorm has three stages of development. They are cumulus, mature, and dissipating. Here’s what the first stage looks like:
You can see it comprises of the warm, moist updraft. Warm air rises and as it does, it expands and cools. This leads to condensation and the creation of cumulus clouds. The updraft becomes strong and clouds grow vertically into “towering cumulus.”
The second stage is the mature stage and pictured here:
Now the storm has an updraft and a downdraft. The updraft consists of warm, moist air inflow, while the downdraft has cool air.
A microburst is a localized column of sinking air, usually less than 2.5 miles wide.
It is caused when the rain drops fall through dry air, evaporate and cool, accelerating to the ground. Due to the intensity of the wind, it hits the ground and spreads out. The strong winds can cause significant tornado-like damage. The debris is typically scattered in a straight-line fashion. Therefore, microbursts are also called “straight-line winds.”
Microbursts can have winds approaching 170 mph. The microburst that hit Ada clocked winds of 100 mph.
There are no “microburst warnings”. They are hard to detect on radar because they occur suddenly. Microbursts are classified under “severe thunderstorm warnings” due to their ability to produce damaging winds in excess of 58 mph.
As meteorologists, we are constantly examining new ways to improve warnings.
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