Diminishing Bitterroot Snowpack May Lower Summer Streamflow
With another month of less than expected snowfall, the Bitterroot River drainage is now the lowest percentage in Montana, with 85 percent of average.
The USDA Natural Resources Conservation Service (NRCS) reported weather patterns in March favored the northern part of Montana with more snow in the St Mary-Milk River Basin with 108 of average at the beginning of April, a gain of about 5 percent.
Statewide, the snowpack is about 92 of average, according to Brain Domonkos, NRCS water supply specialist. He said, however, that snowpack reaches its maximum in April, so streamflow forecasters are watching the precipitation closely.
Low-elevation snowpacks have been hit hard by recent warm temperatures, but mid and upper elevation snowcourses seem to be holding, he said.
With the current levels, the forecast for the Bitterroot River levels from April through July is only 80 percent of average. That assumes near normal moisture and runoff.