May 20, 2011
A Pacific low moved into the four corners region on the 17th and migrated northeast into the Dakotas through the 22nd, bringing another round of heavy precipitation aided by a tap of Gulf of Mexico moisture. Another system passed to the south on the 23rd and 24th, continuing the precipitation across the area. A new all-time daily precipitation record for Billings was set on May 24th. These two systems brought a total of 4 to 7 inches of precipitation to the area through the 25th. From May 29th t
Source: NOAA National Weather Service Storm Events Database (event 316112). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Custer County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.