What causes downbursts and the impacts they can have
Over the past couple of days, there has been a noticeable trend in storm activity across central Missouri. Although there has not been any widespread severe weather, isolated storms each afternoon have caused brief wind gusts up to 60 mph before dissipating. Just yesterday, one of these storms occurred in the morning, and damages were seen in the city it impacted.
The Mexico Public Safety Department sent out a press release on Monday, August 18th, 2025, about a small storm that moved through at approximately 9:04 AM. Very strong winds were briefly observed, and Mexico Public Safety responded to almost 20 incidents of roadways being obstructed by tree limbs, utility lines, or debris. Signs, street lights, vehicles, and buildings also had visual damage during the event. Luckily, no injuries were reported, but this was still an impactful event, even with its lifespan. More storms were observed throughout the day on Monday, and displayed similar characteristics to the one seen in this specific event.
This event and similar events like it are known as downbursts, which are strong winds that quickly descend from a thunderstorm to the surface and spread out in all directions once they reach the surface. This feature can even be seen on radar if the winds are strong enough. As they hit the surface, they can kick up debris and other non-meteorological substances, and the radar will pick up on this. It is seen as a light green ring gradually expanding from the center of the storm before the storm loses its energy.
This is especially noticeable with short-lived storms that grow very quickly in size but do not have the proper atmospheric setup to maintain the storm's structure. The storms yesterday aligned with this case, as they quickly gained energy in a short period of time, but collapsed shortly after reaching full strength.
Before the collapse, these storms are typically on the stronger side, producing an updraft to maintain its growth in that short period of time. As these storms collapse, it loses its updraft, and the air being pushed up into the storm has no where else to go. The result is the downbursts that have been observed to briefly cause damaging winds before quickly dissipating. This is due to the fact that as the storm collapses, it forces all the energy it has built up during its growth down to the surface. This creates the strong straight-line winds around the entirety of the storm.
There are two different types of downbursts depending on the extensiveness of the winds and damage. Microbursts occur when the downburst and its effects is 2.5 miles wide or less. A macroburst is when the downburst and its effects is greater than 2.5 miles wide.
These downbursts are short-lived, but depending on the overall atmospheric setup, they can be quite frequent. They are most common in setups like the one we have been in where there is plenty of instability/energy for the storms to grow off of, but not much upper-level support. The lack of upper-level support leads to the collapse and eventual downburst with these cases.
