Archived

Avalanche Forecast

Feb 7th, 2017–Feb 8th, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

Regions: Banff Yoho Kootenay.

Wind and storm slabs were less touchy than anticipated on Monday. However, another storm is approaching on Thursday with warm temps. The danger will climb to HIGH by Friday.

Weather Forecast

We expect to see another storm with an increase in temperature to track through the forecast region late on Thursday. Some models suggest up to another 30cm. Strong West wind is also expected. This combination of factors will increase the danger rating.

Snowpack Summary

The recent storm has deposited between 10 and 30cm of snow. Wind effect has generally been light, but soft wind slab formation has been observed in alpine areas where N and E winds have created a reverse loading pattern. All of this sits on a very weak snowpack structure.

Avalanche Summary

Explosive control today produced small results up to size 2 across the forecast region. A recreational party also reported remotely triggering a small size 1 avalanche from about 10m away. This slide occurred at treeline at the Hector Glades above highway 93N.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Friday

Avalanche Problems

Deep Persistent Slabs

This is a weak and difficult to predict problem. We expect it to become more reactive with more load (Thurs), and once triggered may cause large avalanches running into the lower elevations.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3

Wind Slabs

Soft wind-slabs exist at high elevation. Additionally, forecasters noticed wind-slabs in lee areas with a West aspect due to the N and E wind during the last storm.

Keep an eye out for reverse loading created by an upslope storm.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2