Flash Flood in Morton County, North Dakota

Thunderstorms with heavy rainfall continuously redeveloped across far eastern Morton County for several hours during the evening of the 15th. Public reports of three to four inches of rainfall were received in the city of Mandan along with street flooding. Some homes had water in their basements. A 30 foot by 40 foot section of roof collapsed at a bowling alley in Mandan. Newspaper reports were that the flat roof failed as a result of the added stress from the weight of the rain water. Two elementary schools in Mandan also had water damage. There were no injuries or deaths.

An upper level low pressure system moving slowly across west and central North Dakota coincided with afternoon destabilization of the atmosphere to trigger scattered thunderstorms over the southwest and south central parts of the state. A few of these storms became severe during the evening hours with several reports of large hail. In addition, flash flooding from very heavy rainfall was reported over south central North Dakota, where storms redeveloped for several hours over the same general area.