Avalanche Forecast

Archived

Jan 22nd, 2020–Jan 23rd, 2020

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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Very dangerous avalanche conditions will develop as heavy rain falls on dry snow. Avalanches could be widespread and large and destructive. Avoid avalanche terrain and use extra caution near any areas where avalanches could run down from above.

Discussion

Expect snow to turn to rain before daybreak on Thursday and spread to all but the highest elevation slopes. The northwest corner of the zone will receive the most precipitation and will see the most dangerous conditions. Elsewhere, snow and rain may just barely be enough to cause a natural avalanche cycle. Not only is this a dangerous day to be in the mountains due to avalanches, but you'll have a tough time staying dry.

On Wednesday, an observer triggered a small avalanche in the new snow on a northwest aspect at 5,600ft in the Icicle drainage. He also found moist snow surfaces below 3,000ft.

Snowpack Discussion

New Regional Synopsis coming soon. We update the Regional Synopsis every Thursday at 6 pm.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

Wind Slabs

Wind Slab avalanches are the 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.