Flattop Mountain SNOTEL Snowpack: Water Year 2018

Science Center Objects

The Flattop Mountain SNOTEL (SNOw TELemetry) station is one of nearly 600 similar stations operated throughout the western United States by the Natural Resources Conservations Service (NRCS, U.S. Department of Agriculture). These stations measure and record Snow Water Equivalent (SWE), which is the weight of snow water equivalent to inches of water. Most SNOTEL sites also measure temperature and precipitation; many now measure snow depth as well. Various agencies and organizations use the data from the stations to forecast water availability, floods, and avalanche hazard.

Flattop Mountain SNOTEL site.

The Flattop Mountain SNOTEL station has operated since October 1st, 1969. To help calculate water storage and availability during agricultural growing seasons, the data are compiled by water year; a water year runs from 1 October - 30 September. SWE records from the station extend for 33 water years (1970-2002). Precipitation records from the station start water year 1979, with temperature records starting water year 1983.

The Flattop Mountain SNOTEL station is located at approximately 6300 feet in elevation on Flattop Mountain, a high plateau between the Lewis and Livingston Ranges in Glacier National Park, Montana. The site is three air miles south of the Continental Divide. During the winter, complex combinations of weather and terrain determine snowfall at the site. Westerly weather systems predominate, bringing moisture from the Gulf of Alaska or Pacific Ocean. Less frequent northerly systems spill drier Arctic air through passes on the Continental Divide as they slide south along the Rocky Mountain Front. Flattop Mountain's position between the Livingston and Lewis Ranges amplifies the effect of these large-scale weather systems; the two ranges rise 2-4000 feet above the site and orographically wring moisture from both westerly and upslope easterly storms. Flattop Mountain is a useful indicator of snowfall throughout Glacier National Park because it is subject to the factors that influence conditions elsewhere in the park.



  • For details on how snowpack affects the spring opening of Logan Pass, visit our Spring Opening of the Going-to-the-Sun Road web page (Logan Pass is located at 6646 feet elevation along the upper edge of the McDonald drainage, approximately 10 miles southeast of the Flattop Mountain SNOTEL station).
  • To view recent and past SNOTEL data, graphs, and maps of snow distribution visit the Montana NRCS - Snow, Water, and Climate Services Snow Products web page – they provide snow depth data for the Flattop Mountain SNOTEL station under the Daily Products-Reports heading. Also, their detailed map of Montana SNOTEL sites is a great resource.

  • The NRCS, National Water & Climate Center provides access to all SNOTEL data as well as in-depth publications describing the SNOTEL program.

  • Avalanche forecasts for Flathead National Forest, Kootenai National Forest, & Glacier National Park can be found at the Flathead Avalanche Center, which also links to avalanche advisories for areas throughout the western US & Canada.

  • For current & historic river level data, visit the USGS - Montana Current Streamflow Conditions web page.