Archived

Avalanche Forecast

Feb 28th, 2017–Mar 1st, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

Snow is coming, but so is the wind. Danger will increase through the week. Today avoid exposure to slopes with cornices overhead. Cornice failures have been occurring with the fluctuation from brittle cold temps to strong solar.

Weather Forecast

The weather pattern is shifting with a series of storms expected. Today expect increasing cloud, with an alpine high of -15'C and gusty W'ly winds at ridgetop. Overnight flurries are expected to bring ~12cm with winds gusting to strong. Tomorrow will be mainly cloudy with flurries, and a high of -13'C. By Thursday we expect 10cm with strong winds.

Snowpack Summary

Over the past two weeks, dribs and drabs of snow have added up to ~30-50cm over the Feb 14 layer, which is a crust everywhere but north aspects above ~1600m where pockets of surface hoar may lurk. Recent snowpack tests indicate that the Feb 14 interface is bonding. In the alpine, variable winds have formed thin windslabs in immediate lees.

Avalanche Summary

Recent human triggered avalanche activity has been limited to sluffing in steep terrain, and small pockets of reactive windslab in the alpine. In the region, cornices have been failing, providing large triggers. In most cases they have not triggered avalanches, but in a few locations have triggered very large, deep avalanches.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Wind Slabs

Recent winds have been shifting from S'ly to N'ly, forming pockets of windslab in unusual places. If triggered they are likely to be small, but occur in the type of terrain where a fall caused by even a small avalanche could have high consequences.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2