21-22

GNFAC Avalanche Forecast for Tue Mar 29, 2022

Snowpack and Avalanche Discussion

<p>Our level of uncertainty about the avalanche danger is relatively high today. A week of above freezing temperatures weakened the snowpack structure. Last night, elevations above 8000’ experienced below-freezing temperatures which is good for stability. This morning, precipitation started as rain in the Bridger Range before turning to snow. As the storm spreads south, rain will make your day less fun and further saturate and destabilize the snowpack. Conversely, slopes with a thick melt-freeze crust formed by cooler temperatures are more stable. Avoid avalanche terrain if you are breaking through the crust into unconsolidated wet snow remembering that the snowpack is less stable at lower elevations. As I noted from the Bridger Range yesterday, today is “<a href="https://www.youtube.com/watch?v=Fk9evguplag"><strong>Not your normal powder day</strong></a>.”</p>

<p>To understand how weak the snowpack got with the warm temperatures visit the <a href="https://www.mtavalanche.com/avalanche-activity"><strong>avalanche activity log</strong></a>. There are fourteen entries from the last three days. A few highlights include a natural avalanche cycle in the Bridger Range (<a href="https://www.mtavalanche.com/node/26363"><strong>photos and details 1</strong></a><strong>,</strong> <a href="https://www.mtavalanche.com/node/26364"><strong>2</strong></a><strong&gt;, </strong><a href="https://www.mtavalanche.com/node/26365"><strong>3</strong></a&gt;), wet snow avalanches intentionally triggered by the YCSP that buried a road (<a href="https://www.mtavalanche.com/node/26377"><strong>photos and details</strong></a>) and widespread terrain closures and natural inbounds avalanches at Big Sky, Bridger and Yellowstone Club (<a href="https://www.mtavalanche.com/node/26375"><strong>photos and details</strong></a>).</p>

<p>Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential. The danger is CONSIDERABLE due to large variation between slopes at different elevations and a higher than normal level of uncertainty.</p>

<p>Temperatures in the higher elevations in the mountains around Cooke City dropped to the mid 20s F last night and are forecast to drop into the low 20s F by early afternoon. Lower elevations that didn’t get as cold are suspect for wet snow avalanches if you are breaking into unconsolidated wet snow.</p>

<p>The high peaks did not escape the warmup without a wet avalanche cycle. Alex took photos of a couple of larger wet slab avalanches (<a href="https://www.mtavalanche.com/images/22/wet-slab-south-silver-gate"><stro…;) and many loose snow avalanches (<a href="https://www.mtavalanche.com/images/22/wet-slides-peak-9595-near-ynp"><s…;) on his drive into Cooke City Sunday. Skiers captured some excellent images of yesterday’s avalanche activity (<a href="https://www.mtavalanche.com/node/26382"><strong>photos and details</strong></a>). Avoid steep slopes with unsupportable wet snow and on all others dig down to assess the snowpack for a persistent weak layer of facets under 1-3’ of snow that has resulted in recent avalanches including one that caught three skiers last Thursday (<a href="https://www.mtavalanche.com/node/26321"><strong>video, photos &amp; details</strong></a>).</p>

<p>Human-triggered avalanches are possible in the mountains around Cooke City where the danger is rated MODERATE.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), 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.

Wet Snow Avalanches Cooke City

COOKE CITY
Cooke City
Code
WS-N-R2-D2-O
Latitude
45.02020
Longitude
-109.93800
Notes

Skiers noted recent wet slab and wet loose avalanche activity on March 28th in the mountains near Cooke City. Most likely occurred on 3/27.

Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Explosive and skier triggered wet slabs at Y.C.

Yellowstone Club
Northern Madison
Code
WS-AE-R4-D2
Elevation
8400
Aspect
NE
Latitude
45.23110
Longitude
-111.44100
Notes

"We also conducted avalanche mitigation on our Cabin’s Road at 4:30pm. The snowpack in this zone doesn’t get skied and is representative of the backcountry. The slope is ENE around 8,400’. Several wet slab aslabnches were produced with explosives and ski cutting. The avalanches ranged from R4/D2 to R2/D1. They all hit the road and several crossed, and buried, the Cabin’s Road. Although most of this mitigation was done with explosives, it took minimal effort with skis to get snow moving. The crowns were 2-3’ deep and ran on the ground."

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
An explosive thrown or placed on or under the snow surface by hand
R size
4
D size
2
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year