Snowpack making gains, thanks to recent storms

After a somewhat warm and dry start to the snow accumulation season across most of Montana, the weather took a timely turn during the last week of December, according to the most recent snow report from the USDA Natural Resources Conservation Service (NRCS).

“Since then, much of Montana has received significant snowfall, however gains were not equivalent across the state,” said Eric Larson, NRCS hydrologist.

Northwest Montana was an exception, receiving near normal precipitation mid-October through early December.

Aside from several storms early in January, last month was relatively dry in that part of the state. The region extending from the Sun-Teton-Marias to the Kootenai only received 30-50% of normal January precipitation.

In contrast, central Montana and the Bighorn Mountains received 190% of normal January precipitation while Southwest Montana and southcentral Montana received about 80-110% of normal January precipitation, and some higher elevation SNOTEL sites measured slightly more than that.

The snowpack continued making gains during the first week of February across all of Montana as storms rolled across the region.

As of Feb. 7, 2025, the mountain snowpack across most of Montana remains slightly below normal at around 80-90% of median, but there are exceptions. The Smith-Judith-Musselshell basin is reporting a 120% of normal snowpack with most of that snow arriving since the last week in December. Several SNOTEL sites in the Little Belt and Big Snowy mountains received their largest January snow accumulation in 20 years.

In contrast, the Sun-Teton-Marias and St. Mary currently have a 65-75% of normal snowpack with snow-water equivalent deficits in that region ranging from 2 to 7 inches.

Snowpack percentages in the Gallatin, Bighorn and Tongue River basins are currently about 100% of normal with additional snow in the forecast. All other basins are reporting a snowpack about 80-90% of normal, except the Bears Paw near Havre.

“Don’t forget, last year was one of the lowest snow years on record,” Larson said. “While recent snow conditions have been excellent for recreating, lack of early season snowfall left most of Montana with a deficit.”

Two to three months remain in the normal snow accumulation season and deficits that exist in many locations could be eliminated by several weeks of active weather.

“Given the major weather pattern change experienced over the last month and half, the outlook that snowpack conditions will continue to improve throughout the next month is good,” Larson said.  

However, if drier weather returns during February, deficits in parts of Montana could be difficult to overcome as spring approaches. Larson said the Rocky Mountain Front is one of the regions that might not recover.

During a typical year, 60-70% of the seasonal snowpack has accumulated by Feb. 1. “March 1 conditions will give a better indication of what spring runoff might bring,” he predicted.

A full report of conditions on Feb. 1 can be found in the monthly Water Supply Outlook Report available on the Montana Snow Survey website. In addition, real-time snow survey data can be found at nrcs.usda.gov/montana/snow-survey.