High winds that were part of a massive system of thunderstorms that struck across South Dakota damaged trees, homes, and buildings in southeastern South Dakota. The National Weather Service is focusing on two main areas: Sheldon, Iowa and Garretson, South Dakota.
Mike Foos is a meteorologist and forecaster.
"We are thinking, just estimating from our radar signature that we had, that it is very possible, at this early time, we think Garretson had 90-95 mile per hour winds," Foos says. "So, yeah, that would cause a lot of damage, and it did: outbuildings, lots of trees, sidings roofs, that sort of nature."
Foos says NWS experts are assessing the scene in Garretson to determine whether the wind estimates they took match the level of damage.
The meteorologist says strong winds hit communities in eastern South Dakota even after the main thunderstorms moved through. Foos says a wake low followed. He says that's a way the atmosphere tries to balance itself out with 20 to 30 minutes of continued strong winds.
Foos says the NWS noted winds of around 80 miles per hour in DeSmet, 60 mph out of Geddes, and more than 60 in Sioux Falls, Madison, and Brookings – all after the rain.