Archived

Avalanche Forecast

Feb 7th, 2017–Feb 8th, 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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

4: High

The avalanche danger rating in the alpine will be high

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.

Expect conditions to vary greatly with aspect, elevation and exposure to wind. Recent storm snow will get it's first kiss from the sun today. Be cautious on solar aspects if the solar radiation feels strong.

Weather Forecast

Expect another cold day today, with alpine temps around -16, however the winds should be light to moderate from the SW and we may see some sunshine. Wednesday will be similar with an alpine high of -12. Wednesday night a weather system will finally make it's way into the region bringing rising freezing levels, strong winds and up to 35mm by Friday.

Snowpack Summary

Strong N'ly winds, combined with ~30cm of low density snow has reverse loaded slopes and formed wind slabs on lee features. The storm snow overlies a variety of surfaces; sun crust on steep solar slopes, hard windslabs in the alpine and gully features, small surface hoar and facets. As the storm slab develops it is unlikely to bond well.

Avalanche Summary

Strong N'ly winds triggered several size 2-2.5 natural avalanches along the highway corridor. They were primarily from steep paths with lee start zones, and avalanches ran well onto the fans. Skiers/riders have reported triggering slabs up to 60cm deep, with some remote triggering from up to 50m away. Propagation has been minimal in the soft slab.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Storm Slabs

30cm of storm snow overlies a variety of surfaces to which it may bond poorly. Skiers have triggered small, unsupported slopes. As the snow settles and forms a slab expect it to become more reactive and capable of propagating into larger avalanches.

Choose regroup spots carefully.Watch for signs of instability such as whumpfing, or cracking.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Wind Slabs

N'ly winds at ridgetop, and downflow winds in valley bottoms and drainages have changed the landscape, forming drifts and windslabs in unusual places. Be especially cautious on S'ly aspects where reverse loading has formed windslabs on a suncrust.

Sheltered slopes at lower elevations will offer the best skiing today.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3