Derecho development is necessarily tied to the formation of bow echoes. A bow echo usually arises from a cluster of thunderstorms but also may evolve from a single strong storm. Bow echoes most frequently occur when atmospheric winds are relatively strong and unidirectional (i.

The derecho caused widespread wind damage from Iowa to Indiana and produced the tornado that hit the Des Moines metro.

The line of storms that swept through most of Iowa Monday hit a notable benchmark. According to the Storm Prediction Center, Monday's storms have officially classified as a derecho. It's Iowa's second derecho in the last two months,

Powerful winds, prolific lightning, and torrential rain swept across eastern Iowa Monday afternoon and evening. Now, officials with the National Oceanic and Atm