The storm system responsible for the tornadoes affected a large area from North Dakota to New Mexico.
On May 20, a strong low pressure system moved on to the British Columbia coast, bringing with it a cold front over the Rockies, although it produced no showers.
[4] Dry line activity increased over the Great Plains and many tornadoes formed in South Dakota.
[7] Dry line activity held steady and a number of more tornadoes formed across the Great Plains.
The tornado then tracked northeast, quickly intensifying into an EF3 where it slammed into a second farm 1.5 mi (2.4 km) northwest of Bowdle.
Several other outbuildings were completely destroyed.The tornado then toppled six to eight metal power transmission towers as it moved to the north of the farm.
The large tornado began to track east, declining to EF2 intensity before crossing over SD-47 where a state radio tower was toppled.