Avalanche Forecast

Issued: Dec 28th, 2020 5:17PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

Grant Statham,

Email

The snowpack is stabilizing well after last week's storm. Despite the recent wind effect up high, nice powder snow conditions exist at treeline and below. We continue to track the persistent weak layers and do not fully trust them yet.

Summary

Weather Forecast

A ridge of high pressure over the region will keep skies mostly clear, temperatures cool and winds light on Tuesday - looks like an awesome day! Another system will move over the area on Wednesday afternoon, bringing overcast skies and a few flurries but no significant accumulation is expected.

Snowpack Summary

Small amounts of new snow now bury wind slabs created by recent 25-45km/hr SW-W winds redistributing the 30-60cm of snow from the past week. The Dec 13 and Dec 7 sun crust/surface hoar/facet layers are down ~ 50cm and ~80 cm respectively. The decomposing Nov crust/facets sits at the bottom of the snowpack. Height of snow at tree line is 120-170cm.

Avalanche Summary

Two new small slab avalanches observed in Paradise Valley, both in the alpine and both size 1 windslabs. Otherwise, a detailed look at a lot of terrain over the last few days shows very little recent activity (last 48-hours), but lots of evidence of avalanches that occurred within the last week and are now buried with small amounts of new snow.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Old windslab formed last week are are now buried with new snow, expect to find small, spotty slabs as you enter open areas at Tree Line and into the Alpine.

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
  • Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

There are a variety of weaker layers down ~50-80cm. These are the Dec 7 and 13th layers of facets, suncrust, and isolated surface hoar. These layers deserve constant suspicion, they can change quickly from one aspect to another.

  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 29th, 2020 4:00PM