Montana snowpack holding steady to start year

Snowpack in the Flathead River basin was slightly above average at the onset of 2023 after a cool and wet November and December brought ample snowfall across most of Western Montana, federal water specialist report.

Natural Resources Conservation Service data shows nearly all river basins in Western Montana with above average or average snowpack. The exceptions are the Upper Clark Fork and Bitterroot basins, which were about 90% of average.

Snowpack in the Milk River basin east of Glacier National Park was the highest at 159% of normal.

The Flathead Basin was at 105% of average. A weather station at Noisy Basin in the Swan Range on Jan. 10 shows a snow depth of nearly 6 feet holding a snow-water equivalent of 22 inches. A station on Flattop Mountain in Glacier National Park showed about 5 feet of snow.

According to an NRCS press release Monday, a late October winter storm brought widespread precipitation to Montana. That snow was within one to two weeks of the typical snowpack onset and earlier than the fall of 2021, which was nearly a month late in some locations due to an unseasonably warm and dry fall.

Coupled with plentiful snow to end the year, water supply specialist Eric Larson said the state is off to a good start.

While the snowpack is currently at or above normal, Larson said it is still early in the winter and a lot can change. On Jan. 1 the snowpack is typically only about 35% to 40% accumulated for the season.

“In a perfect world, the snowpack reaches normal peak snow water equivalent levels in April or early May,” said Larson.

Peaking early generally results in less late-summer water supply, while peaking late can potentially result in flooding. Water supply specialists generally have a better idea of the spring and summer water supply outlook closer to April, the NRCS release stated.

"While the snowpack conditions are currently above normal, several weeks without snow could leave us with a similar snowpack to last year in many basins. On Feb. 1, 2022, snowpack was slightly below normal, except in northwest Montana where it was above normal,” said Larson.

If snowfall continues at a similar rate to the last couple months, Montana snowpack could accumulate a buffer in the event of a pause in active weather later this winter.

A shift in the weather is possible this weekend following a period of generally cloudy and dry weather across Northwest Montana. Mountain snow and valley rain is possible Saturday, according to the National Weather Service in Missoula.

Early next week a longstanding ridge could finally breaks down, which would usher in a more active weather pattern.