Avalog
Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Register
Login
Archived

Avalanche Forecast

Jan 22nd, 2018–Jan 23rd, 2018
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: Glacier.

Several surface hoar layers in the upper snowpack are sensitive to human triggering. A small avalanche could initiate a deeper instability resulting in a large avalanche.Avalanches from the Alpine have the potential to reach Valley Bottoms.

Weather Forecast

Today will be a lull between storms, with the next notable amount of snow coming in Tuesday evening into Wednesday. Today you can expect cloud and sunny breaks with periods of light snow. Freezing level to remain at valley bottom with and Alpine high of -8. Winds at ridge top will be 20-35km/hr from the southwest.

Snowpack Summary

17cm of snow overnight, ~50cm of storm snow sits atop the January 16 surface hoar layer which is settling quickly and reactive in tests. The December 15 surface hoar is down 100cm and is highly visible in profiles and still producing sudden planar results in tests. Strong south winds have built pockets of wind slab in the Alpine.

Avalanche Summary

Several natural avalanches size 2-3.5 yesterday. The size 3.5 dusted and spread small woody debris on the highway for a 100m section.Avalanches originating in the Alpine have the potential to run into valley bottoms.

Confidence

Avalanche Problems

Storm Slabs

Strong south winds combined with recent new snow has formed pockets of wind slab. This buries the Jan 16 surface hoar which is widespread and found down ~50cm. Slabs triggered over this weak layer could propagate far and trigger deeper layers.
Use caution in alpine lees. Recent snowfall mixed with wind loading has created storm slabs.If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1.5 - 2.5

Persistent Slabs

The January 4th surface hoar is down 70cm and the Dec 15th layer is down 100cm. After a month under the snow, this surface hoar remains widespread and well-preserved. These layers should not be overlooked and could be sensitive in thin areas.
Dig down to find and test weak layers before committing to a line.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3.5