Wind Slabs
N
NE
E
SE
S
SW
W
NW
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Possible
- Tamaño
- 1–2
Boletín de aludes
Ver en el mapaBridger Range
Gallatin NF Avalanche Center
Peligro de aludes
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Desactualizado: este boletín caducó 6 months ago. Estás viendo condiciones pasadas, no el boletín vigente.
Lo esencial
It’s tricky out there with some avalanches happening this week following the Mon/Tues storm. Wind slab avalanches may break up to 2 feet deep while persistent slab avalanches may break 1 foot deep. Read more below.
Problemas de aludes
Persistent Slabs
NNEESESSWWNW- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Possible
- Tamaño
- 1–2
This problem seems to be less of an issue on southerly facing slopes with a thick ice crust on top of the weak layer.
Avalanche Discussion
A widespread weak layer exists under snow that fell early this week, a foot of snow in many places, which has created a persistent slab avalanche problem. That weak layer of facets formed during the dry weather in January and the start of February. There have been some avalanches on that layer especially in places with more snow, and especially on slopes with wind slabs from strong winds on Monday and yesterday morning.
- Yesterday I rode through much of the Cooke City area finding unstable results in a snowpit in one place but not another.
- Local ski guides in Cooke experienced some collapsing and cracking yesterday, and other guides and riders spotted 5 recent avalanches (view slides here)
- Skiers in the Southern Madison Range in areas west of Hwy 191 in Bacon Rind and Tele meadows have reported widespread collapsing and shooting cracks.
- In the Bridger Range, Ian and I in separate locations found generally stable snow while a skier triggered a slide in Wolverine Bowl on Monday, and Ian spotted slide on Saddle Peak on Tuesday
- In Hyalite, skiers saw a recent slide on Mt Blackmore and Divide Peak
- Just south of Big Sky on Tuesday, Dave found 5-7” of new snow and mostly stable conditions.
- I spotted one recent wind slab avalanche just west of Sawtell Peak near Island Park on Tuesday.
It’s tricky because you may not see avalanches or other obvious signs of instability.. Some slopes do have stable snow, but some do not. While riding yesterday, what scared me was that I was letting my guard down because I wasn't seeing obvious signs of instability.
What to do? A great option, and my first choice, is to ride slopes less than 30 degrees in steepness that aren’t steep enough to slide. Otherwise, start by avoiding areas loaded with wind drifted snow. Places further south near West Yellowstone and Island Park received less snow, thus will have more slopes with stable snow. Before committing to a steep slope, consider digging on a nearby low angle slope about 2 feet deep (you’ll see the obvious layers) and do a few Extended Column Tests looking for unstable results (ECTP’s). Lacking any of those red flags, pick slopes with clean runouts free of trees, rocks, creeks, or other terrain traps.
The avalanche danger throughout the forecast area is MODERATE.