'Exceptional set of circumstances' converge to shatter streamflow records across southern Montana

Low temperatures and persistent precipitation combined with an unusually high June snowpack to set the stage for historic flooding in southwest and south-central Montana this week. At least five rivers in Park, Carbon and Stillwater counties set all-time records for high flows, wiping out bridges and roads and sending entire buildings downstream in the process.

Ed McIntosh, a meteorologist with Billings news station Q2, said a recent cycle of precipitation from the West Coast brought a significant amount of rainfall to southern Montana, where it went to work melting an already ample snowpack i...