Archived

Avalanche Forecast

Apr 30th, 2017–May 1st, 2017

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Glacier.

Today is the last day of the winter permit system. New snow in the alpine accompanied by strong south winds will make things feel wintery up high and storm slabs will be reactive to human triggering.

Weather Forecast

A mix of sun and cloud today with isolated flurries. Freezing levels should remain below 1700m and winds will be moderate from the SW. More of the same for Mon and Tues, then a dramatic warm-up on Wed-Thurs with freezing levels rising to 3000+m and light precipitation.

Snowpack Summary

High elevation N aspects still hold a winter snowpack with surface windslab that may be sensitive to human triggering given the right location. On all other aspects, expect temperature and sun crusts until daytime warming softens the surface. The snowpack is isothermal below these surface crusts at tree-line and below tree-line elevations.

Avalanche Summary

No new activity has been observed. Glide cracks continue to widen with the Spring warming and are very difficult to predict when they will fail.

Confidence

Avalanche Problems

Wind Slabs

Expect to find pockets of windslab on high elevation N aspects formed by the new snow being redistributed by S-SW winds.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3

Loose Wet

Surface crust breakdown can be expected with daytime warming. Wet slides will occur once the crust softens.

Use extra caution on solar slopes or if the snow is moist or wet.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Cornices

Cornices are huge and hanging over alpine lee slopes in many places. Daytime warming may promote failure of these large triggers. Cornice failure may wake persistent weak layers.

Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3