Flash Flood in Sioux County, Iowa

Water ponding in the area of Central Park overflowed roadways and entered the Sioux Center Fire Department building. Two homes suffered the collapse of basement walls from the high water. Water also inundated a transformer which cut off power to seven homes in the northwest part of town. Seven trailers were evacuated due to high water in Westbrook Village on the northwest edge of town. More than two dozen vehicles were stranded in high water. Damage costs are rough estimates.

An outflow boundary from earlier day convection focused a gradient of instability and storm development with additional destabilization from heating by early afternoon. Boundary interactions from sluggish storms led to training of heavy rainfall cores, as well as a couple brief tornadoes. Extensive flooding resulted in a state disaster declaration for Sioux County.