23-24

GNFAC Avalanche Forecast for Wed Feb 7, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>We are continuing an Avalanche Warning in the southern Gallatin and southern Madison Ranges, the Lionhead area and Island Park. Very dangerous avalanche conditions exist.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Island Park received a foot of new snow with 50+ mph wind gusts. The southern mountains, including West Yellowstone picked up another 6”. It has been snowing since Friday with Island Park receiving a total of 28” (3” </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat… water equivalent</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>) and 18” in Lionhead and the southern mountains (1.6-2” </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat…;). The snowpack is weak and unstable and the weight of the new snow will cause widespread avalanches. It is still snowing and blowing. On Monday, Dave and I threaded our way up Bacon Rind and triggered collapses and wide cracks every time we stepped off the skin track (</span></span></span></span></span></span><a href="https://youtu.be/zcBGHzPcXtw"><span><span><span><strong><span><u><span>…; and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30508"><span><span><span><strong><span…;). More snow since then is keeping the backcountry dangerous and triggering a deadly avalanche is very likely. </span></span></span></span></span></span><span><span><span><span><em><u><span><span>Today is a day to avoid being on or underneath avalanche terrain</span></span></u></em></span></span></span></span><span><span><span><span><span><span>. The avalanche danger is HIGH.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Since Friday, the mountains around Bozeman, Big Sky, and Cooke City have been incrementally loading every day with a total snowfall of&nbsp; 8-12” (0.8-1.2” of </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat…;). Avalanche activity early in the week in </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30495"><span><span><span><strong><span… Basin</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and in the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30517"><span><span><span><strong><span… Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> point to a snowpack with poor stability. In Cooke City, Alex has been skiing and riding and found a dangerous snowpack both north (</span></span></span></span></span></span><a href="https://youtube.com/shorts/c7XwPvZ93ZU?feature=share"><span><span><span…;) and south (</span></span></span></span></span></span><a href="https://youtube.com/shorts/uJXOKijsY38?feature=share"><span><span><span…;) of town. A sledder confirmed the poor stability when he triggered a slide in “The Plug” on Highway 212 east of town (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30537"><span><span><span><strong><span… and photo</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Ian and I skied into Beehive Basin yesterday. The snowfall since Friday has doubled the slab depth above our problematic December weak layers (</span></span></span></span></span></span><a href="https://youtube.com/shorts/doG4m6lbQqY?feature=share"><span><span><span…; and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30528"><span><span><span><strong><span…;). Traveling in avalanche terrain is dangerous. As it keeps snowing it will get easier to trigger slides 1-2 feet deep. Passing beneath steep slopes is not advised as collapses warn us that we can trigger slides from flat ground. The avalanche danger is CONSIDERABLE.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

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

Snowmobile triggered avalanche above Highway 212, Cooke City

Cooke City
Code
SS-AM-R1-D1-O
Elevation
8200
Aspect
NE
Latitude
45.00860
Longitude
-109.86700
Notes

Observed an avalanche above Highway 212 ("the plug") just north of the Wyoming/Montana border. that appeared to be triggered by a snowmobile. It looked fresh, likely from the afternoon of 2/6/2024. Northeast facing slope, 8200'. Technically out of the advisory area. 

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

From obs: "Observed an avalanche above Highway 212 ("the plug") just north of the Wyoming/Montana border. that appeared to be triggered by a snowmobile. It looked fresh, likely from the afternoon of 2/6/2024. Northeast facing slope, 8200'. Technically out of the advisory area." Photo: N. Gaddy

Cooke City, 2024-02-06

From obs: "Observed an avalanche above Highway 212 ("the plug") just north of the Wyoming/Montana border. that appeared to be triggered by a snowmobile. It looked fresh, likely from the afternoon of 2/6/2024. Northeast facing slope, 8200'. Technically out of the advisory area." Photo: N. Gaddy

Cooke City, 2024-02-06

Snowmobile triggered avalanche above Highway 212

Date
Activity
Snowmobiling

Observed an avalanche above Highway 212 ("the plug") just north of the Wyoming/Montana border. that appeared to be triggered by a snowmobile. It looked fresh, likely from the afternoon of 2/6/2024. Northeast facing slope, 8200'. Technically out of the advisory area. 

Region
Cooke City
Observer Name
Nick Gaddy

Mount Henderson summit

Date
Activity
Skiing

Evidence of an old natural slide on the lee side of Henderson Mountain. 

No obvious signs of instability or cause for concern on the relatively mellow route up the ridge, but would definitely avoid the lee sides of that area where there was significant cornice formation.

Region
Cooke City
Location (from list)
Henderson Mountain

Stable snow in South Plateau

Date
Activity
Snowmobiling

We rode South Plateau the last three days. The snow has been stable on steep slopes. We did observe a fresh powder layer of 24" with an ice layer beneath that is roughly 4" thick and faceted snow another 12" down with another ice layer. The snow has been very stable while we are riding and we have not observed any slides or had any issues. 

Observer Name
Adam kupiec

Loose Snow Avalanches Henderson Mt. Cooke City

Lulu Pass
Cooke City
Code
L-N
Latitude
45.07090
Longitude
-109.95800
Notes

Snowmobilers near Henderson Mt. saw several small loose snow avalanches near the top of the ridge. These avalanches were isolated to the new snow. 

Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Natural trigger
Problem Type
New Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year