10 South Dakota Counties Most Likely to See Tornados

Seeing a tornado is like winning the lottery. Everyone talks about it, sometimes it's all they talk about, but you rarely ever see one. If you do see one up close, there is a chance your life will change dramatically.

Tornados are "[a] violently rotating column of air extending from the base of a thunderstorm down to the ground." They're like a super compacted hurricane that drops out of a thunderstorm.

ELBERT COUNTY, CO - MAY 8: A small funnel cloud forms in the distance during a supercell thunderstorm, May 8, 2017 in Elbert County near Agate, Colorado. Meteorologists from the Center for Severe Weather Research try to get close to supercell storms and tornadoes trying to better understand tornado structure and strength, how low-level winds affect and damage buildings, and to learn more about tornado formation and prediction. (Photo by Drew Angerer/Getty Images)

HOW DO TORNADOS FORM?

One of the things that make tornados particularly scary is that we don't really know how they form. Our understanding of these weather phenomena is growing exponentially, but there's still a lot to learn.

Tornados are formed in super-cell thunderstorms. Rotation in the storm seems to lead to the formation of the collum of spinning air that becomes the tornado.

WHERE DO TORNADOS OCCUR?

Tornados can occur anywhere in North America, at any time of day and the year. The US averages about 1200 a year. However, the central plains of the United States is known as Tornado Alley because of the clashing of cold dry air from the Rocky Mountains with warm moist air from the Gulf Of Mexico. This confluence can bring together the right pieces for regular tornadic storms.

In recent years researchers have noticed that Tornado Alley is shifting to include states in the southeast US.

SUNBRIGHT, TENNESSEE - APRIL 3: In this aerial view, buildings sit destroyed by a tornado on April 3, 2024 in Sunbright, Tennessee. The tornado caused extensive damage. (Photo by Brett Carlsen/Getty Images)

IS SOUTH DAKOTA IN TORNADO ALLEY?

Nebraska, Kansas, and parts of South Dakota are in Tornado Alley. South Dakota averages just over 30 tornados a year. Most of them are short-lived, small funnels in the EF-0 to EF-1 range on the “Enhanced Fujita Scale, which measures the strength of a twister.

Possibly the biggest tornado to rip through South Dakota was in Tripp County, in southeast South Dakota. In May 1965 an F5 tornado touched down and streaked across the countryside with 200 mph winds for 30 miles.

In September 2019 three EF-2 tornados touched down in Sioux Falls, the state's largest city. They damaged several buildings before lifting back into the clouds.

WINCHESTER, INDIANA - MARCH 15: An aerial view shows homes destroyed by a tornado on March 15, 2024 in Winchester, Indiana. At least three people have been reported killed after a series of tornadoes ripped through the midwest. (Photo by Scott Olson/Getty Images)

Because southern and eastern portions of South Dakota make up the northern end of Tornado Alley, the counties in this part of the state tend to see more tornados than the rest of the state. More than 100 twisters have been identified in the area since 2000.

South Dakota's Tornado Alley region does include Minnehaha and Lincoln Counties, home to Sioux Falls and the over 300,000 people that call the metro area home.