When you read the story published by the local newspaper, it sounds like kind of a freak accident. Knowing that avalanches aren’t really precarious, but occur when a predictable set of conditions converge. Key to an avalanche being big enough to take out a house is a slope nearby that is steep enough. A quick look at Google maps confirmed several residential homes off Rattlesnake Drive back up to the base of a slope off Mount Jumbo with pitches in the 30 degree range. A small, natural gully exists where the avalanche ran which ends on Holly drive, where the homes were hit by the avalanche.
The local avalanche forecast for the day was rated High for all slopes 30° or more near Missoula, with special mention made of Mount Jumbo. A nearby ski resort, Montana Snowbowl reported 15 inches of snow the previous day. Weather reports and the avalanche advisory warned of high winds and cold temperatures leading to the potential for high avalanche danger.
A local witness who lived nearby said, “I could feel the rumbling.” According to comments on the story the area where the slide occurred is considered off limits. No word on whether charges will be filed against the person who triggered the slide but local police are investigating the incident.
Updated report from Teton Gravity Research.
Avalanche Advisory for March 1st, 2014 from MissoulaAvalanche.org.
NBCMontana news report
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