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Weather Wise: Spring avalanche dangers

Weather Wise: Spring avalanche dangers
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There has been a lot of dangerous avalanche activity in Montana and the west recently. Less than a week ago, a group of five people were backcountry skiing outside of Lost Trail Pass in the Bitterroot Mountains where one person was caught and killed by a slide. That marked 12 fatalities in the country this season.

As of March 18, many mountain ranges had a moderate to high avalanche danger. The avalanche danger scale goes from low to moderate to considerable to high, with extreme rating the greatest threat. The Cabinet, Purcell, Flathead, Whitefish, Swan mountain ranges and parts of Glacier National Park near Marias Pass were issued an avalanche warning as large and deadly avalanches are likely.

As temperatures warm up this time of year, wet snow avalanches become likely in sun-affected terrain. But this recent warm spell is creating avalanche conditions on north-facing slopes at mid and lower elevations.

Going back earlier this year to November and December's warm, dry spell throughout the west set the stages for some of the current risks of deep avalanches. Weak, frictionless layers were created by the slow start to the season.

Since the beginning of January, significant snow has fallen across a lot of the west burying these weak layers, setting the stages for large, deadly slides.

Snowpack stability will continue to be a concern later into the spring this year.