The snowpack has a strong distaste for rapid change. Thursday and Friday were relatively mild and warm with many mountain locations at or above freezing. This likely created a crust upon which this new snow falls. Then, temperatures plummeted with new snow and wind in a very short time span. The crust is now another bed surface for avalanches to slide on. But, let's not forget about that pesky weak snow (facets) near the ground that developed during the early November cold snap. While the recent mild weather may have helped to strengthen this layer a bit, it still exists and should be treated as suspect especially with a heavy, rapid load like this. This weak early season snowpack is a tough pill to swallow as everyone is powder starved, but the snowpack is weak. The strong winds with this storm likely created wind slabs as well. East-northeast winds may have deposited snow on slopes we are not accustomed to seeing as typical wind loaded slopes. 

Conservation decision making and terrain selection is hugely important if you choose to venture out today. Avoid steep slopes, areas with deposited snow, and stay out of runout zones. Allow the snowpack time to adjust, and remember that it may take a few days or more for this to occur. Carry your avalanche gear (beacon, shovel, and probe) with you. Look for obvious signs of instability like recent avalanche activity, cracking of the snowpack, and whumpfing (collapsing). Also, with a shallow early season snowpack any avalanche (even a small one) could take you for a nasty ride over rocks and stumps. Ask yourself if early season turns or riding is worth it before committing to any steep slope. 

We are currently in the field getting a handle on the snowpack. We need more data before we begin issuing hazard ratings and regular advisories. We intend to issue our first advisory December 6, and, until then, will provide updates as conditions warrant. If you are out in the backcountry please send us your observations by submitting them on the Observations page, emailing us at [email protected], or by calling 406.387.3835. 

Our data are limited due to very few observations, but the amount of new snow accompanied by strong winds have likely created unstable conditions. I observed a moist, dense snow surface and a shallow snowpack the past two days near Big Mountain in the southern Whitefish Range and a weak snowpack in the Swan Range last Tuesday (video).

Remember that at this time there is no avalanche control and the slopes at ski areas have uncontrolled backcountry conditions. The terrain at ski areas can feel safe and familiar, but currently the snowpack there is just the same as the backcountry. It is important to carry your beacon, shovel, and probe when traveling in the backcountry at all times.