21-22

We were able to trigger a couple small slabs of wind-drifted snow at the ridgeline of Divide Peak on 2/18/22. This is a sign recent drifts are unstable for a day or two. Some recently formed wind slabs could be large enough to bury or injure a person. Photo: GNFAC

Northern Gallatin, 2022-02-18

We were able to trigger a couple small slabs of wind-drifted snow at the ridgeline of Divide Peak on 2/18/22. This is a sign recent drifts are unstable for a day or two. Some recently formed wind slabs could be large enough to bury or injure a person. Photo: GNFAC

Northern Gallatin, 2022-02-18

GNFAC Avalanche Forecast for Fri Feb 18, 2022

Snowpack and Avalanche Discussion

<p>The Bridger Range and mountains near Big Sky saw the most snowfall from this week’s storm (up to&nbsp; 1-1.5 ft of fresh snow). While some slopes had slightly less new snow, on others the new snow has been drifted into even deeper drifts. Yesterday, Alex and Doug were in the Bridgers and I was on Buck Ridge. In both places we only saw small avalanches breaking in the new snow, but identified the potential for larger slides (<a href="https://www.mtavalanche.com/images/22/small-avalanche-buck-ridge"><stro…;, <a href="https://www.youtube.com/watch?v=uIJ0t3fBQDo"><strong><u>Bridgers video</u></strong></a>, <a href="https://www.youtube.com/watch?v=WyJv7snrlDM"><strong><u>Buck Ridge video</u></strong></a>). Large avalanches are possible on any slope with more than around 8” of new or drifted snow. Avoid steep slopes where deeper cohesive drifts are likely, especially below corniced ridgelines. Avalanches could also break wider and less predictably on weak layers buried a few inches below the old snow surface. Triggering large avalanches is very much possible today and the avalanche danger is MODERATE.</p>

<p>&nbsp;</p>

<p>Near Cooke City, there was less new snow, but it fell onto weak layers buried a foot and a half to two feet deep that avalanched after last week’s snowfall (<a href="https://mtavalanche.com/node/25840"><u>Wyoming Creek avalanche details</u></a>, <a href="https://mtavalanche.com/node/25847"><u>Silver Gate avalanche details</u></a>). Skiers on Henderson Mountain yesterday saw large drifts actively forming, which will make these weak layers even more sensitive. Triggering avalanches on these weak layers remains possible and the danger is MODERATE near Cooke City.</p>

<p>5-8” of new snow over the last four days in Hyalite, the southern Madison Range, and the Lionhead area accompanied by strong westerly winds means it is possible to trigger large avalanches on wind-loaded slopes. Weak layers in the upper snowpack are widespread but on slopes without a thicker slab of cohesive, wind-drifted snow, avalanches are unlikely. Steer clear of wind-loaded slopes to avoid triggering a large slide. The avalanche danger is MODERATE on wind-loaded slopes and LOW on all others.</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>

Upcoming Education Opportunities

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

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

Snowmo triggered small slide near Cooke

COOKE CITY
Cooke City
Code
SS-AM-R1-D1-O
Aspect
N
Latitude
45.02020
Longitude
-109.93800
Notes

From FB message: "north facing slope small avalanche about 30foot wide two feet deep slide around 75 yards down. This was human triggered and it was triggered saturday the 12 at around 4:30 pm."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
R size
1
D size
1
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Small storm slabs on Buck Ridge

Buck Ridge
Northern Madison
Code
SS-N-R1-D1-S
Latitude
45.17190
Longitude
-111.38000
Notes

3 small storm slab avalanches were observed along Buck Ridge on 2/17/22. These slides broke <6" deep within the new snow and were less than 50 ft wide. 

Number of slides
3
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1
Bed Surface
S - Avalanche released within new snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year