March did little to improve Montana snowpack

Laura Lundquist

(Missoula Current) After a March when most locations saw lower than average snowfall and warmer temperatures, the snowpack in Montana remains far below average.

The mountain snowpack remains at about 70% as Montana heads into April, according to the U.S. Natural Resources Conservation Service. The snowpack started the month of March with about 70% of what it should have, and the snows that blew through did little to improve that. As the National Weather Service Missoula Office said in a social media post, “March came in like a lamb and left like a lamb.”

The snow in upper Clark Fork Basin that feeds the Clark Fork River above Missoula contains just two-thirds of its 30-year average. The Bitterroot, Flathead and lower Clark Fork are only a bit better with about 73% of their normal snowpack. Worst off is the Rocky Mountain Front and the Sun-Marias-Teton basins with just 57% percent of their normal snowpack.

As climate change is predicted to slowly limit snow to higher elevations, some mountain valleys did especially poorly this year. Missoula saw only 22% of its normal snowfall while Kalispell did slightly better with 43%, according to the National Weather Service Missoula Office.

Warmer temperatures in parts of western Montana were partly responsible for the lack of snow down low. An area from Polson south to the Big Hole Valley and west across Idaho into Oregon and Washington was 1 to 2 degrees warmer than the average temperature for March, according to the National Weather Service Climate Prediction Center. For the month of March, the average temperature in both Missoula and Kalispell was 1.4 degrees warmer than normal.

However, little precipitation fell across the state in March. While parts of central Montana saw average precipitation and northeastern Montana received slightly more than normal, western Montana received less than 75% of normal precipitation for the month and the high mountains of the Bob Marshall Wilderness Complex got only about half of its normal precipitation, according to the National Weather Service Climate Prediction Center. Missoula and Kalispell received 50-60% of its normal precipitation for the month.

But the drought in western Montana is not improving. According to the U.S. Drought Mitigation Center Drought Monitor, 95% of the state is experiencing drought, about the same as at the start of the month. As of March 26, most of western Montana is in at least moderate drought, with all of the area around Missoula except for the Bitterroot Valley in severe drought. A region of the Blackfoot Valley between Bonner and Lincoln and north to Seeley Lake remains in extreme drought, along with a region along the northern Continental Divide.

Based on the forecast for April, the moisture situation doesn’t seem like it will improve, according to the National Oceanic and Atmospheric Administration. The monthly outlook shows a likelihood for warmer than normal temperatures across the state while precipitation should be about average. Then the three-month outlook has warmer-than-normal temperatures continuing through June for western Montana.

Streamflow predictions are not yet available but since there is little chance that the snowpack will catch up this year, streams will likely drop early in the summer and the drought will continue, posing a higher risk for wildfire.