Key takeaways
- A loose-snow avalanche (point-release, 'sluff') starts at one point and fans out in a teardrop shape.
- It involves loose, cohesionless snow with no cohesive slab.
- Generally smaller and less deadly than slab avalanches.
- Still dangerous — can knock you down, carry you over cliffs, or bury you in a terrain trap.
This is general educational information, not avalanche-safety training. Avalanches are deadly — get formal avalanche education, carry rescue gear, and check the local forecast.
What a loose-snow avalanche is
A loose-snow avalanche (also called a point-release avalanche or ‘sluff’) starts at a single point and fans outward into a teardrop shape as it entrains more cohesionless snow on the way down. It involves loose, unconsolidated snow — not a cohesive slab releasing at once.
How it differs from a slab avalanche
A loose-snow slide starts at one point and widens as it descends, releasing snow that lacks cohesion. A slab avalanche releases a whole cohesive block at once along a fracture line, sliding on a weak layer. Slab avalanches cause the great majority of fatalities; loose-snow slides are generally smaller.
Dropping into a steep couloir, a skier triggers a sluff that starts under their skis and fans out below them — a loose-snow point-release. They ski to the side of the moving snow, aware that even a small sluff could sweep them toward the cliff band at the bottom.
Are they dangerous?
Generally less deadly than slab avalanches, but still dangerous: a loose-snow slide can knock you off your feet and sweep you downhill — hazardous above cliffs, into terrain traps (gullies, creeks), or over other bad terrain. Dry sluffs matter in steep terrain, and large wet point-releases can be very destructive. It’s one avalanche type alongside the slab and wet avalanche.
The bottom line
A loose-snow avalanche (point-release or sluff) starts at a single point and fans out in a teardrop shape, involving cohesionless snow rather than a slab. Generally smaller and less deadly than slab avalanches, it's still dangerous — it can knock you down and sweep you over cliffs or into terrain traps, and big wet point-releases pack a punch. Respect it for the terrain consequences below.
Frequently asked questions
What is a loose-snow avalanche?
A loose-snow avalanche, also called a point-release avalanche or 'sluff,' starts at a single point and fans out downhill into a teardrop or inverted-V shape, gathering more loose snow as it goes. It involves cohesionless, unconsolidated snow rather than a cohesive slab releasing all at once, which gives it its distinctive spreading shape.
How is a loose-snow avalanche different from a slab avalanche?
A loose-snow avalanche starts at one point and widens as it descends, releasing snow that lacks cohesion. A slab avalanche releases a whole cohesive block of snow at once along a fracture line, with the slab sliding on a weak layer. Slab avalanches are responsible for the great majority of avalanche fatalities because they release large volumes suddenly; loose-snow slides are generally smaller, though not harmless.
Are loose-snow avalanches dangerous?
They're generally less deadly than slab avalanches, but still dangerous. A loose-snow slide can knock you off your feet and sweep you downhill, which is especially hazardous above cliffs, into terrain traps (gullies, creeks, trees), or over other dangerous terrain. Dry sluffs matter in steep terrain (and to climbers and steep skiers), and large wet point-release avalanches can be heavy and very destructive. So they warrant respect, particularly given the consequences of the terrain below.
Sources
- Avalanche types & safety — American Avalanche Association
- Avalanche awareness — Utah Avalanche Center