May brought an early melt and below-normal snowpack in much of the state
Warmer than normal temperatures last month resulted in rapid snowmelt throughout much of the state. That has some experts hoping for a very wet June to help bolster projected streamflows as we head into the drier summer months.
According to the U.S. Department of Agriculture's Natural Resources Conservation Service in Bozeman, this year’s snowmelt happened about 10-20 days earlier than normal. NRCS says snowpack percentages dropped from near- or above-normal to less than half that in nearly all Montana basins since May 1.
One exception is part of southwest Montana, which had a near record snowpack along the Idaho border. Several snow recording stations in the area, known as SNOTEL, still have an above-normal snowpack.
Seasonal water supply forecasts vary widely. The Beaverhead, Ruby, Smith, Boulder, Musselshell, and Madison rivers are expected to have well above-normal stream flows through September. Forecasts are lowest in northwest Montana and the northern Rocky Mountain Front.