Flash Flood — Sioux, North Dakota

2019-07-08 to 2019-07-09 · near Ft Yates, Sioux, North Dakota

Event narrative

Flash flooding resulted in a section of BIA Road 3, locally known as the Kenel Road which connects with ND Highway 1806, being washed out at the crossing with Joe Bush Creek. The culvert washed out and the road collapsed. Four vehicles drove into the washout and resulted in two fatalities and two injuries.

Wider weather episode

A surface boundary stretching from southwest into north central North Dakota served as the primary focal point for thunderstorm development in an atmosphere of very high instability. Initially, large hail was the main threat, though a couple of tornadoes developed in an area of enhanced low level shear. Later, storms mainly developed along an old outflow boundary and were slow moving. This combined with a moisture rich atmosphere which led to a heavy rain threat, in addition to a hail and strong wind threat. The heaviest rain fell over Sioux and Emmons counties, where there were multiple reports of over four inches of rain. In Sioux County, on the Standing Rock Nation, flash flooding from the heavy rain resulted in a section of BIA Road 3, locally known as the Kenel Road, being washed out at the crossing with Joe Bush Creek. The culvert washed out and the road collapsed. Four vehicles drove into the washout and resulted in two fatalities and two injuries. The largest hail reported in this episode was golf ball size, and fell in Divide, Morton, and Burleigh counties. The strongest wind gusts were 60 mph, and occurred in Wells and Divide counties.

View location on OpenStreetMap → (45.9437, -100.5232)

Source: NOAA Storm Events Database, event_id 831940. Narrative written by the NWS forecast office that issued the report.