Hydrologic response for a high-elevation storm in the South Dakota Black Hills

A group of thunderstorms produced >4 in of rain during four periods of progressively more intense rainfall across a small part of a relatively high-elevation area of the northern Black Hills on 5 August 2014. The resulting hydrologic response was noteworthy in two very small headwater drainage basins, where the measured peak flows are by far the largest—relative to drainage area—ever documented for the high-elevation Limestone Plateau area. However, peak flows attenuated quickly in a downstream direction owing to the storms tracking perpendicular to the drainage direction, moderately dry antecedent conditions, and progressive widening of the valley bottoms.