Archived

Avalanche Forecast

Apr 29th, 2017–Apr 30th, 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.

Early starts and early finishes are the safest way to approach Spring travel. Be aware that the frozen valley-bottom surface you skied on in the morning will be mush in the afternoon.

Weather Forecast

Mainly cloudy today with isolated flurries during the day and ~10cm of snow tonight. Freezing levels will rise to 1800m and winds will be light to moderate from the SW. Mixed sun and cloud Sunday through Tuesday with freezing levels hovering around 17-1800m until Wednesday, when we should see a dramatic warm-up with freezing levels rising to 2900m.

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

A size 3.5 natural glide crack avalanche adjacent to the highway released during Thursday morning. No other new activity has been observed.

Confidence

Avalanche Problems

Wind Slabs

Expect to find pockets of windslab on high elevation N aspects formed by recent S-SW winds.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Watch for whumpfing, hollow sounds, and shooting cracks.

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 may occur later in the day.

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

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.

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

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3