NORTH CAROLINA -- A microburst damaged a school gym at Union Intermediate School in Sampson County Monday afternoon.  Around a dozen students were in the gym at time, and three of them were sent to a hospital. Fortunately, they are all expected to be OK.

That storm damage has had many folks asking our Weather on the 1s team - what is a microburst?

Microbursts form in strong thunderstorms like the one over Sampson County Monday afternoon. As storms develop, there is a lot of upward motion in the storm, or what we call an updraft. That updraft suspends a lot of rain drops and sometimes hail toward the top of the thunderstorm cloud. 

Drier air around the thunderstorm cloud can then cause evaporative cooling. That cooling process weakens the updraft, sending the core of the storm rapidly toward the ground.  As it hits the ground, wind expands out in all directions causing straight-line winds that can be up to 100mph.

 

 

In the case of the Sampson County microburst, the National Weather Service has estimated wind speeds were up to 85mph.

Microbursts can cause damage similar to an EF-1 tornado. Microburst damage typically occurs in a small area spread out from a central point. Tornado damage occurs along a path.

On the same day as the Sampson County microburst, a brief EF-1 tornado touched down at a high school in Loris, South Carolina near the North Carolina state line. The tornado flipped several cars in the school parking lot.

Both of those storms are good reminders for us all to take tornado warnings and severe thunderstorm warnings seriously.