Archived

Avalanche Forecast

Apr 1st, 2016–Apr 2nd, 2016

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

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

1: Low

The avalanche danger rating below treeline will be low

Regions: Glacier.

There has not been an overnight freeze above treeline for several days. Danger ratings will rise quickly as natural avalanche activity is expected to commence once the sun hits the snow.

Weather Forecast

We are in for another very warm and sunny day. Freezing levels may rise to 3000m today, with alpine temps of 5'C in the shade... Temps were above freezing overnight so it won't take long for the sun to break down surface crusts. Saturday and Sunday will have increasing clouds, with isolated showers, alpine temps of 4'C and freezing levels to 2400m.

Snowpack Summary

Temps have stayed above freezing in the alpine for over 72hrs, preventing an overnight recovery. At treeline the top meter is ~isothermal and moist. Surface crusts forming overnight are weak and break down quickly. Multiple crusts in the top meter of the snowpack provide sliding surfaces. Dry snow exists on steep N aspects in the high Alpine.

Avalanche Summary

Widespread natural avalanches occurred yesterday from all aspects and elevations. Most were size 2-2.5 but several very large size 3 avalanches put wet debris into valley bottoms. Avalanche activity has been beginning mid morning and generally follows the sun occuring from sun exposed slopes. Glide cracks continue to release deep wet slabs.

Confidence

Avalanche Problems

Loose Wet

Above freezing overnight temps mean that the snowpack will destabilize quickly once the sun hits a slope. Be very conscious of the aspects you are exposed to; even if you are in the shade the start zone above you may be cooking in the sun.

Avoid exposure to sun exposed slopes.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Cornices

Very warm temperatures and strong solar may weaken large cornices that exist along many ridges. Cornice failures are likely triggers for deeply buried weak layers and may trigger very large avalanches.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood: Likely

Expected Size: 2 - 3

Persistent Slabs

Intense solar and warm temps could wake up deeply buried weak layers. Recent tests on these crusts indicate that they will likely take a heavy trigger like a cornice fall or another avalanche, but if triggered very large avalanches are possible.

Choose well supported terrain without convexities.Use extra caution on slopes if the snow is moist or wet.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 4