The Corn Belt derecho was a progressive derecho which affected a large area of the central United States on June 29, 1998. In the morning, thunderstorms, including a supercell, developed over South Dakota and tracked into central Iowa. As the thunderstorms reached central Iowa, a strong rear-inflow jet developed which caused the thunderstorm to take on a different characteristic, becoming a derecho. It traveled more than 600 miles in about ten hours, causing more than $125 million worth of widespread damage destruction, especially to crops, and was responsible for power outages to nearly a half a million people.