Wednesday, June 19, 2024

Northwest Montana mountain snowpack rebounds in May

Daily Inter Lake | May 27, 2024 12:00 PM

High-elevation snowpack in the Swan Range has remained near or above historical averages for most of May thanks to a series of cold storms that dumped snow and rain across the region.

The snow-water equivalent measurement registered at 39.1 inches for Noisy Basin on May 26, according to data collected at a SNOTEL weather station located at 6,040 feet. The median for that date is 31.6 inches. The snow-water equivalent is the amount of water held in the snowpack.

Likewise, about 83 inches of settled snowpack remains at Noisy Basin, considerably more than the median of 65.5 inches for May 26. 

While a dry winter fueled by an El Nino weather pattern kept Northwest Montana's mountain snowpack below average through the beginning of May, late-season snow storms have maintained and even added to the snow depth in some areas.

The Noisy Basin snowpack actually peaked for the season on May 9 at 108 inches. The peak depth normally occurs in mid April before completely melting out by late June.

It’s a similar situation for Northwest Montana’s other mountain ranges.

A weather station on Flattop Mountain in Glacier National Park showed a snow depth of 72 inches on May 26, slightly below the median of 80.5 inches. Snow depth at Stryker Basin in the Whitefish Range was 50 inches, while Big Mountain's upper reaches still held 53 inches of snow.

Overall, the Flathead Basin snowpack was 85% of normal on May 26, and 79% in the Kootenai Basin.

In the valley, Kalispell has seen measurable precipitation on 15 days so far this month. Between May 22-25, about 1.13 inches of rain was measured at Glacier Park International Airport. Precipitation month-to-date for Kalispell is 1.89 inches, slightly higher than the average of 1.42.

The Flathead River at Columbia Falls crested at 8 feet during the recent rainy spell and was expected to rise to 10 feet by mid week. Flood stage is 13 feet.

Potent and potentially dangerous thunderstorms could affect the Flathead Valley on Tuesday. Heavy rainfall of half an inch in 30 minutes is possible. Urban areas could see ponding of water in poor drainage areas if they take a direct hit from a storm, according to the National Weather Service in Missoula.

Temperatures will run 5-10 degrees below normal, with overnight lows dipping into the 30s Wednesday night through Friday.

High pressure returns by the weekend with pleasant temperatures in the 70s.