Avalanche Forecast

Sunday is a day to look for wind transported snow. These are the spots where you are most likely to get into trouble. Do you see fresh cornices? Are there snowdrifts behind rocks and trees? Does the snow surface appear uneven? Is the snow slightly firmer than other locations you’ve been traveling? If you answer, “yes,” wind slabs are likely on nearby slopes. Our recent winds have been out of the NE and E. As a result, you can find wind slabs in unusual locations, including areas normally scoured by the wind. You are most likely to find wind slabs at higher elevations and near exposed ridgelines.

Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..

Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.

Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.

With all the recent light, fluffy, unconsolidated snow you may trigger loose dry avalanches in sheltered locations. While these avalanches shouldn’t be big, don’t let them catch you off-guard. Be cautious around slopes where loose dry avalanches can push you off of cliffs, into trees, or bury you deeply in a gully.

Release of dry unconsolidated snow. These avalanches typically occur within layers of soft snow near the surface of the snowpack. Loose Dry avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs. Loose Dry avalanches can trigger slab avalanches that break into deeper snow layers.

Loose Dry avalanches are usually relatively harmless to people. They can be hazardous if you are caught and carried into or over a terrain trap (e.g. gully, rocks, dense timber, cliff, crevasse) or down a long slope. Avoid traveling in or above terrain traps when Loose Dry avalanches are likely.

Loose Dry avalanche with the characteristic point initiation and fan shape.

Loose dry avalanches exist throughout the terrain, release at or below the trigger point, and can run in densely-treed areas. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells.