Archived

Avalanche Forecast

Dec 31st, 2016–Jan 1st, 2017

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Banff Yoho Kootenay.

With cold temperatures approaching expect upper snowpack instabilities to become less reactive. Keep in mind that the persisted problem will take some time to heal.

Weather Forecast

One last pulse of snow is expected tomorrow bringing 3-5cm to the Bow Valley. As the approaching high pressure system moves in temperatures are expected to drop with highs around -15 and lows in the mid -20's.

Snowpack Summary

We have received 30-60 cm of new snow and strong winds this past week. This new snow sits over the Dec facet interface which continues to be touchy. Above tree line windslabs have develop creating another reactive interface near the surface. With approaching cold temps , upper snowpack instabilities are expected to become less reactive.

Avalanche Summary

No new natural avalanches observed today, better visibility confirm the recent cycle with numerus avalanches to size 2.5 . Lake louise reported numerus avalanches to size 2 and one size 2.5 triggered with explosives today. Avalanches were initiated in the windlsab problem and stepped down to deeper instabilities.

Confidence

Avalanche Problems

Persistent Slabs

The Dec 19 facet interface is 30 to 100cm down. This interface is poorly bonded, resulting in many recent avalanches. This weak, faceted layer will persist for some time.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 2 - 3

Wind Slabs

Thick wind slabs have formed in the lees of alpine features. Once initiated, they may trigger a persistent slab on the Dec.19th facets. As temperatures drop this week, expect this problem to become less reactive.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2