Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 1.5–2.5
Recent wind loading will make this problem more likely today.
Bollettino valanghe
Vedi sulla mappaNorthern Gallatin Range
Gallatin NF Avalanche Center
Pericolo valanghe
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Non aggiornato — questo bollettino è scaduto 8 months ago. Stai vedendo condizioni passate, non il bollettino in corso.
In sintesi
A few inches of new snow yesterday, hurricane force winds, more snow coming today, and more strong winds, mean that avalanche conditions remain dangerous.
Drifts and wind slabs formed yesterday plus new ones today can avalanche. They will also add weight and stress to the snowpack and keep persistent slab avalanches a serious threat. Seek out slopes sheltered from the wind and less than 30 degrees in steepness.
Problemi valanghivi
Wind Slabs
NNEESESSWWNW- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1–1.5
Look for drifts at all elevations although they're more likely as you get higher.
Avalanche Discussion
Hurricane force winds ripped across the landscape yesterday toppling trees and knocking out power in places. For the snowpack, these winds drifted snow across all elevations. More winds are coming today.
Even though it didn’t snow a ton, that dense snow combined with drifting added weight to the snowpack especially on wind loaded slopes. That extra weight means more stress on weak, faceted layers near the ground. Ian says it well in his video from Cooke yesterday (full ob here). Stress on that weak snow means the persistent slab avalanche problem remains a serious concern.
At low elevations (except near Cooke City), the snowpack became wet during recent warm weather and during some rain yesterday. It should be solidly refrozen this morning, and the occasional wind slab will be the only thing to look out for.
The challenge today will be finding slopes sheltered from the wind. Watch out for and avoid fresh drifts and wind slabs that can avalanche. The wild card is old faceted snow near the ground that has created a persistent slab avalanche problem. This weak layer is at all elevations near Cooke City. In all other areas, it is at mid and upper elevations and was unaffected by recent warm weather (see this layer in my video from Island Park yesterday, Dave's from Beehive, Alex's from Blackmore). My best advice is to not mess with this problem and wait until it gets buried deeply, and we stop seeing avalanches breaking on those facets.
Dangerous avalanche conditions exist throughout the forecast area and the danger is CONSIDERABLE
Check out recent observations and avalanche activity on our new observation page. You can view avalanches in lists and charts, sort by area, and sort by timeframe. A new feature is that you can move the map to other areas and see observations in places like the Tetons or Sawtooths.