Northwest Montana snowpack dips below average
Feb. 7—Mother Nature took the "dry January" trend to heart in Montana.
After generous pours of snowfall in November and December, the winter spigot was all but corked at the start 2023. As a result of a weather pattern change that pushed the supply of Pacific moisture south of the Northern Rockies, mountain snowpack dropped below average in January for river basins across Western Montana.
According to data from the Natural Resources Conservation Service, the Flathead Basin snowpack on Tuesday was at 99% of normal for this time of year. The Kootenai was at 80% of normal, and the Lower Clark Fork Basin was at 84%.
A weather station at Noisy Basin in the Swan Range on Feb. 6 showed a snow depth of 90 inches holding a snow water equivalent of 106% of average. In comparison, Flattop Mountain in central Glacier National Park had a snow depth of 73 inches holding a snow water equivalent of 84% of average.
The snowpack improves east of the Continental Divide, with the Jefferson, Madison and Gallatin basins all reporting above average snow totals, as of Tuesday.
According to Eric Larson, an NRCS water supply specialist, January precipitation totals were lowest along the Rocky Mountain Front, northeastern Montana and western Montana. Most of southwest Montana received slightly less than normal January precipitation.
"The storm which brought 2 to 3 feet of mountain snow in many locations during the last week of January really saved us. Without that storm, basin-wide snowpack percentages across much of Montana might have looked similar to last year at this time," Larson said in a press release.
River basins west of the Continental Divide saw a 20 to 30% decrease in their snowpack percentages, while Rocky Mountain Front basins saw a 30 to 35% decrease since Jan. 1.
"The good news is above normal snowfall during November and December provided enough of a buffer that the snowpack is still in good condition in most locations," said Larson.
Larson said that while there is plenty of winter left for snow totals to rebound, Northwest Montana has the largest deficit to overcome. High elevation weather stations in the Flathead, Kootenai, Lower Clark Fork and Bitterroot River basins are about 6 to 7 inches of snow water equivalent less than normal for Feb. 1.
"Basins that are well below normal will ideally start recovering soon in order to reach normal snowpack conditions by the end of the snow year," said Larson.
Larson noted that weather stations in the southern Madison and Gallatin River basins have a surplus of about 2 to 4 inches of snow water equivalent, which will act as a small buffer in the event of below normal precipitation ahead.
Looking ahead there is reason to be optimistic, Larson said.
NOAA's Climate Prediction Center indicates near-to-below normal temperature and near-to-above normal precipitation is likely over the next couple weeks across Montana. Additionally, the one-month outlook indicates below normal temperatures are likely in western Montana and above normal precipitation is likely across all of Montana.
