Persistent Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
The likelihood of this problem will increase as snow fall today, but mostly, ferocious winds have added to the uncertainty, thus increased the danger.
Avalanche forecast
View on mapCooke City
Gallatin NF Avalanche Center
Avalanche danger
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Out of date — this forecast expired 5 months ago. You’re viewing past conditions, not the current bulletin.
Highlights
Intense winds and new snow falling make for dangerous avalanche conditions today. Avalanches breaking on weak layers buried 2-3 ft deep on windloaded slopes are the primary concern. It’ll be hard to find slopes that haven’t been affected by the very strong winds, but those slopes will harbor softer snow and less dangerous conditions.
Avalanche problems
Wind Slabs
NNEESESSWWNW- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–1.5
The more new snow falls today, the larger these potential slides will grow.
Avalanche Discussion
Intense winds are drifting snow and loading the weak layers that are buried 2-3 ft deep on most slopes across the forecast area. Triggering an avalanche on these weak layers is likely today, particularly on windloaded slopes (examples of recent Persistent Slab avalanches across the region: Bridger Range, N. Gallatin 1, N. Gallatin 2, N. Madison, Cooke City). The tricky thing is, with such strong winds, winds are blowing snow at all elevations and on slopes that are typically sheltered, so it’ll be hard to find slopes that aren’t wind affected.
If you do manage to find a slope unaffected by the wind, dig down to test the weak layers buried 2-3 ft deep before committing to a steep slope.
Around Cooke City, new snow is an additional complicating factor. Today’s new snow will be blown into drifts as it falls. Slides could break as smaller Wind Slab avalanches within the new snow (see this example from Mt. Republic yesterday), but the bigger issue is that the additional loading will make it more likely that an avalanche breaks on the buried weak layers.
Unusual conditions increase uncertainty and that is true of the unusually strong winds we’ve had over the last 36 hours. Either take a step back entirely from steep terrain today or very carefully assess conditions as you travel. Slopes that have been scoured by the strong winds will be safer, but will also have uninspiring riding conditions and even a generally scoured slope might have a lurking pocket that was windloaded. The avalanche danger is CONSIDERABLE across the region.