23-24

We toured into Beehive Basin and up and over to Bear Basin. The snowpack was thin, a maximum of two feet deep, and it has entirely transformed into piles of weak facets. Off the established skin track, we were breaking through the snowpack nearly to the ground in this weak snow except where melt freeze crusts supported our skis. We were hunting for slopes that still had a cohesive slab above the sugar and couldn't find it ourselves. We dug four snowpits and found non-propagating failures or ECTX results. We performed a PST in our pit below the cornice line in Bear Basin to see if we could get the last trace of a slab to propagate failure and got non-propagating slab fracture results.

We did talk to a skier who went farther up the ridge toward Middle Peak. Also hunting for instability, he found one spot with enough of an overlying slab to get propagating test results once, but could not reproduce them in that pit or anywhere else.

Other than watching out for thin snow cover and rocks, we will continue to monitor the snow under our feet as we travel for changes and isolated instability where the slab remains sufficiently intact to produce an avalanche.

Region

Northern Madison

Location (from list)

Beehive Basin

Observer Name

David Zinn

The Missing Ingredient - Beehive Basin - 1 January 2024

Read more about The Missing Ingredient - Beehive Basin - 1 January 2024

GNFAC Avalanche Forecast for Mon Jan 1, 2024

Snowpack and Avalanche Discussion

With each day without new snow, triggering avalanches becomes less likely. Field observations of instability, such as collapsing and unstable test scores, have significantly decreased in frequency and volume, and the last known backcountry avalanche in our area occurred one week ago in the Bridger Range (<a href="https://www.mtavalanche.com/node/29711">details and photo</a>).

Four ingredients are necessary for a dangerous slab avalanche: a steep slope, a weak layer, a slab of cohesive snow above the weak layer, and a trigger. Yesterday, Alex explained from Cooke City that persistent weak layers exist within the snowpack on nearly every slope in the advisory area, but weeks of mostly clear and sunny weather have deteriorated the slab above them, removing a critical ingredient on many slopes (<a href="https://www.youtube.com/watch?v=09FTVj-Uh7g">video…;). Human-triggered avalanches are still possible on slopes where cohesive slabs rest on top of weak layers. Specific slopes loaded with snow drifts within the last week are areas of concern (<a href="https://www.youtube.com/watch?v=YSYlarbuzJQ&list=PLXu5151nmAvSH326z… Fork video</a>, <a href="https://www.youtube.com/watch?v=Rd_XSNJjLYs&list=PLXu5151nmAvSH326z… video</a>).

Avoid avalanches by knowing the snow beneath your feet or sled and recognizing changes to it. For example, is the entire depth the consistency of sugar, or is it supportable? Like the groups in Hyalite Canyon, Beehive Basin, near Cooke City and outside our advisory area in Jardine did this weekend, recognize the whumphing sound of collapses as a sign of instability and an indicator that the avalanche ingredients of a weak layer and slab are present (<a href="https://www.mtavalanche.com/node/29714">Hyalite Ob 1</a>, <a href="https://www.mtavalanche.com/node/29723">2…;, <a href="https://www.mtavalanche.com/node/29715">Beehive Ob</a>, <a href="https://www.mtavalanche.com/node/29716">NE YNP Ob</a>, <a href="https://www.mtavalanche.com/node/29726">Jardine Ob</a>).

Avalanches breaking 1-2 feet deep remain possible on some slopes. Dig and test the snowpack, recognize red flags of instability, carry avalanche rescue equipment, and only expose one person at a time to steeper terrain. The danger is MODERATE across the advisory area.

Read more about GNFAC Avalanche Forecast for Mon Jan 1, 2024

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.

Every weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.