GNFAC Avalanche Forecast for Mon Oct 21, 2019

The mountains have seen a big change in the last four days. Slopes that were bare last week are now covered by up to 18” of new snow. On these recently bare slopes, avoiding rocks and stumps hiding just under the surface is the number one concern. Slopes that held snow before this weekend will make for easier travel on skis, but also have the most potential to avalanche (photo). This older snow is generally present above about 8000’ feet, particularly in wind drifted areas and on shadier aspects.

Yesterday, ice climbers in Hyalite triggered a small slide as they approached a climb (photo). While this slide was small, getting swept off your feet could have disastrous consequences will all the rocks still exposed this time of year and bigger avalanches are also possible.

Any slope with old snow is suspect. The only way to know whether it’s there is to dig down to look for it. If you find the old snow, take a minute to do a quick Extended Column Test. Watch this video to remind yourself how to do one. You’ll spend longer watching the video than it’ll take to do the test. Also keep your eye out for thicker wind drifts and stay alert for signs of instability such as recent avalanche activity, cracking or collapsing of the snowpack. Any of these signs are a clear warning to avoid steep slopes.

Hunters, ice climbers, and skiers have all been caught in early season avalanches (accident reports). Regardless of activity, the same advice applies: either avoid avalanche terrain (>30 degree snow covered slopes) entirely or bring a partner, travel one at a time, carry the standard rescue gear (beacon, shovel, and probe) and carefully assess the snowpack.

We are preparing for winter, setting up weather stations and beginning to collect snowpack information. If you have avalanche, snowpack or weather observations to share, please submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).