21-22

Natural Avalanche in Wyoming Creek

Wyoming Creek
Cooke City
Code
SS-NC-R2-D2-O
Elevation
9800
Aspect
NE
Latitude
44.98150
Longitude
-109.97400
Notes

From obs 2/12/22: "N-SS-R2-D2-i. Appeared to have happened early in the early morning of 20220212."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Cornice fall
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
12.0 inches
Slab Width
175.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

GNFAC Avalanche Forecast for Sun Feb 13, 2022

Snowpack and Avalanche Discussion

<p>In the mountains near Cooke City a person can trigger an avalanche that breaks&nbsp;1-1.5 feet deep on layers of weak, sugary facets or surface hoar. These buried weak layers are slow to gain strength. While avalanches are becoming less likely after a week without substantial snowfall, they remain possible and would be large enough to bury a person. Before riding in steep terrain assess the snowpack for these weak layers and pay attention to signs of instability like collapsing, cracking, or recent avalanches. On Friday, strong winds formed fresh drifts which put more weight over these weak layers. Be extra cautious of wind-loaded slopes where the snowpack is probably more unstable. Last weekend I was finding these buried weak layers on almost every slope, so ruling out their presence is difficult (<a href="https://www.youtube.com/watch?v=EQDLaHsyinU"><strong>video</strong></a&…;). If you are unsure of the snowpack stability, avoid slopes steeper than 30 degrees. Today, large avalanches are possible to trigger and avalanche danger is MODERATE.</p>

<p>In the mountains near Bozeman, Big Sky, and West Yellowstone the snowpack is generally stable with small and isolated avalanche hazards to watch for. Yesterday on Buck Ridge near Big Sky I found a generally stable snowpack and saw one small cornice fall avalanche off Cedar Mountain (<strong><a href="https://www.youtube.com/watch?v=kRjBQLrFjFk&amp;list=PLXu5151nmAvT1nrM2…;, <strong><a href="https://www.mtavalanche.com/images/22/small-cornice-fall-cedar-mtn">pho…;). Before riding, skiing, or climbing in steep terrain assess the snowpack for drifts of snow that may remain unstable due to resting on weak, sugary snow. Also watch for small wet loose avalanches on steep, rocky slopes that face the sun (<a href="https://www.mtavalanche.com/images/22/small-loose-wet-avalanche-hyalite…;), and cornices along ridgelines that could weaken with sun and warm temperatures. These hazards will exist in isolated areas and are unlikely to produce large avalanches, but they would be harmful if they push you into trees, rocks, or over cliffs. Today&nbsp;the avalanche danger is rated LOW.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong>website<…;, email (<a href="mailto:mtavalanche@gmail.com"><strong>mtavalanche@gmail.com</strong></a…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

Upcoming Education Opportunities

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming

February 19, Women's only Companion Rescue Clinic sponsored in partnership with SheJumps! Register Here.

Cornice fall avalanche on Cedar

Cedar Mtn.
Northern Madison
Code
C-NC-R1-D1-O
Elevation
10500
Aspect
SE
Latitude
45.22680
Longitude
-111.51200
Notes

Seen on 2/12/22 looked to be within 24 hours old.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Cornice fall
Trigger
Cornice fall
R size
1
D size
1
Bed Surface
O - Old snow
Problem Type
Cornice Fall
Vertical Fall
700ft
Slab Width
10.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

GNFAC Avalanche Forecast for Sat Feb 12, 2022

Snowpack and Avalanche Discussion

<p>Near Cooke City, you can trigger avalanches on weak layers buried around a foot and a half under the snow surface. While it’s been almost a week since the last substantial snowfall, avalanches remain possible. There are two primary reasons for this. First, the weak layer of near surface facets and surface hoar isn’t gaining strength quickly (<a href="https://www.youtube.com/watch?v=EQDLaHsyinU"><strong><u>video</u></stro…;). With this sort of weak layer avalanches are possible days after the last loading event. Secondly, strong winds have continued loading these weak layers and building cohesive slabs above them. This means that on some slopes it hasn’t been a week since they were loaded, they are instead freshly loaded and ready to avalanche. Avoiding steep slopes is the simplest way to avoid these concerns. If you are getting into steep terrain, dig down to analyze the weak layer and watch for unstable snowpack test results, collapses, shooting cracks, or recent avalanches as signs to retreat to lower angled slopes. Large human-triggered avalanches are possible and the avalanche danger is MODERATE.</p>

<p>Large avalanches are unlikely in the rest of the advisory area. Still, stay on alert in case you find an isolated instability. Issues to watch for are wind drifts that haven’t bonded yet, pockets where weak layers in the top foot and a half of the snowpack have a cohesive slab on top and remain unstable, and maybe very small loose wet avalanches on sunny slopes with the warm temperatures this afternoon (<a href="https://www.mtavalanche.com/images/22/small-loose-wet-avalanche-hyalite…;).&nbsp;</p>

<p>Safe travel practices provide an extra safety margin in case of surprises. This means carrying rescue gear (beacon, shovel, probe), only exposing one person at a time to steep slopes and watching your partners while they’re in avalanche terrain. The avalanche danger is rated LOW.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>&nbsp;</p>

Upcoming Education Opportunities

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming 

February 19, Women's only Companion Rescue Clinic sponsored in partnership with SheJumps! Register Here.