Archived

Avalanche Forecast

Feb 16th, 2018–Feb 17th, 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

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

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

Regions: Glacier.

Ongoing winds continue to load storm slabs. Extra caution is required when transitioning into exposed and wind-loaded terrain.

Weather Forecast

Snowy conditions today with 5cm of accumulation. Cool temperatures with an alpine high of -10.0 and westerly winds gusting to 45km/h. A weak low pressure system spreads isolated flurries into late Saturday. On Sunday, cold arctic air replaces the low pressure, with temperatures dipping down to the nether regions of tolerable.

Snowpack Summary

Storm snow remains unsettled with up to 50cm of ski penetration. Ongoing southerly winds have created reactive pockets of wind slab in exposed areas. On solar aspects, a well developed crust is buried 40cm. Persistent weak layers from January and December are now buried 150-200cm.

Avalanche Summary

A natural avalanche cycle occurred yesterday, corresponding to loading from strong daytime winds. A size 3.0 and four size 2-2.5 natural avalanches were recorded in the highway corridor east of Rogers Pass. A size 2.5 was reported in Connaught drainage in the Cheops North 1 slide path that ran to the valley bottom, nearly hitting the skin track.

Confidence

Avalanche Problems

Storm Slabs

Natural and skier triggered avalanches are still resulting from this reactive storm slab problem. Loading from moderate to strong southerly winds has increased the likelihood storm slabs being triggered and propagating, especially in exposed areas.

Use caution in lee areas in the alpine and treeline. Storm snow is forming reactive slabs.If triggered the storm 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

These slabs will be most susceptible to triggering in shallow areas. This type of instability will linger for a while yet. The significant storms seen recently have overloaded these layers, priming slopes to fail only awaiting a trigger.

Avoid thin, rocky or unsupported slopes.Be aware of the potential for large avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 4