Declining mountain snowpack is a concern

The mountain snowpack percentage in Montana has declined significantly in the past two months, the U.S. Natural Resources Conservation Service in Bozeman reports. Lack of snowfall and above normal temperatures are to blame.

“Basins west of the Continental Divide have seen the most substantial change since Feb. 1, with basin snowpack percentages declining 9 to 16 percent during the month,” NRCS reported March 6. “East of the Continental Divide, most of the basins saw a decline in snowpack percentages, but not to the extent of the western part of the state.”

Mountain snowpack in the Flathead River basin is 88 percent of the median for March and 75 percent of last year. The Kootenai River basin is down to 60 percent of the median and 58 percent of last year.

“As disappointing as the declines and below normal snowpack percentages may be, Montana is in good shape snowpack-wise compared to most of the West this water year,” said Lucas Zukiewicz, an NRCS water supply specialist for Montana.

Above normal snowfall before Jan. 1 helped Montana snowpacks remain near normal for this time of year.

“Winter is not over,” Zukiewicz said. “Many basins east of the Divide are favored in the coming months regarding snowfall, and a pattern change would certainly be welcome at this point.”

If snowpacks continue to decline, streamflow prospects will likely follow suit.

“This month, our forecasts have dropped in almost every basin due to the declining basin percentages of normal snowpack,” Zukiewicz said.

Assuming normal moisture and runoff conditions for February through July, the streamflow forecast for April through July this year for the Flathead River basin is 99 percent of average and 72 percent of last year. For the Kootenai River basin, the forecast is 89 percent of average and 76 percent of last year.