May 26, 2018
A cold front extending from a surface low over Saskatchewan, combined with a strong low pressure trough over northeast Montana amid a very unstable atmosphere to produce numerous thunderstorms, some of which became severe. Later in the evening, some of these storms merged together, produced strong winds as they departed Montana. In addition, heavy rain, caused a few roads to wash out.
Source: NOAA National Weather Service Storm Events Database (event 757928). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in McCone County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.