Archived

Avalanche Forecast

Nov 22nd, 2016–Nov 23rd, 2016

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

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

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Glacier.

The Winter Permit System in now in effect (click here for more information). A series of storms may bring up to 40cm by Friday; avalanche danger is expected to increase through the week.

Weather Forecast

Today is forecast to be mostly cloudy and dry with moderate S'ly winds at ridgetop. On Wednesday the first in a series of Pacific storms is expected. Wed expect 5cm, Thurs 20cm and Fri another 20cm! Combined with moderate to strong S'ly winds, expect new storm slabs and windslabs to develop.

Snowpack Summary

Over the past week 70cm of snow fell at 1900m and is settling into a slab. This slab sits on the November 13 crust. Recent tests on this interface indicate that in some areas the slab may bond poorly and may be triggered by skiers. Yesterday the winds increased, with S'ly winds loading lee slopes and forming pockets of windslab at ridgetop.

Avalanche Summary

Yesterday skiers reported remotely triggering a size 2 windslab in Dispatchers Bowl. The avalanche occurred from a SE aspect at 2540m. The slab was 20-40cm deep. In addition, several size 1.5 to 2.5 avalanches were triggered naturally by windloading in steep paths off Mt Macdonald and Mt Tupper. Skiers have also reported sluffing from steep slopes

Confidence

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

Avalanche Problems

Wind Slabs

After an extended period of relative calm, winds picked up over the past 48 hours. S'ly winds have loaded lee slopes forming pockets of windslab and building new touchy soft cornices. Yesterday skiers triggered a size 2 windslab from a SE aspect.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

Below the light and powdery surface snow a slab is developing, and it sits on a hard crust. Recent tests have shown that this interface is becoming one to watch. With the forecast storms expect it to be increasingly reactive.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.Choose regroup spots that are out of avalanche terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3