Sarah Spivey, KSAT Weather Authority Meteorologist
You might have heard the term āstraight-line windsā after a storm rolls through and leaves behind a trail of damage. But what exactly causes them? A downburst could be the answer, and understanding how one forms helps explain why the destruction can be so widespread.
Whatever the Weather
A collection of daily blog posts from the KSAT Weather Authority.
What Is a Downburst?
It all starts with a strong thunderstorm. Here is how the process unfolds:
A strong thunderstorm develops a powerful updraft, feeding winds up into the storm
Over time, the updraft weakens
Colder air builds in the middle of the storm
Gravity takes over, creating a downdraft
That surge of air hits the ground hard and spreads out in all directions, causing damage
Itās important to know that downbursts can be just as damaging as a tornado.
Why Does It Matter?
Unlike a tornado, which spins and follows a relatively narrow path, a downburst spreads outward from a single point. That is why the damage pattern looks different. Trees and structures get pushed away from a central spot rather than twisted. The winds are straight-line, not rotational.
Justin Horne is a meteorologist and reporter for KSAT 12 News. When severe weather rolls through, Justin will hop in the KSAT 12 Storm Chaser to safely bring you the latest weather conditions from across South Texas. On top of delivering an accurate forecast, Justin often reports on one of his favorite topics: Texas history.
Sarah Spivey is a San Antonio native who grew up watching KSAT. She has been a proud member of the KSAT Weather Authority Team since 2017.
Sarah is a Clark High School and Texas A&M University graduate. She previously worked at KTEN News.
When Sarah is not busy forecasting, she enjoys hanging out with her husband and cat, and playing music.
