Archived

Avalanche Forecast

Apr 5th, 2016–Apr 6th, 2016

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

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

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: South Rockies.

Sunny skies will cause hazard to increase rapidly. Failing cornices could trigger large avalanches running to valley bottoms. Watch out for overhead hazard.

Confidence

High

Weather Forecast

Tuesday night: Extreme westerly winds expected overnight. Wednesday: Partly sunny skies. Strong to extreme westerly winds in the morning that diminish in the afternoon. Freezing level around 2200m. Thursday: Sunny skies, light winds, and freezing levels skyrocketing to 3500m. Friday: Sunny skies, light winds and freezing levels remaining around 3500m.

Avalanche Summary

No new avalanches were reported in this region on Monday.

Snowpack Summary

Cornices are large, fragile, and could trigger deep slab avalanches running to valley bottom. 10cm of recent storm snow with moderate westerly winds have created thin fresh wind slabs on lee aspects in the alpine and open treeline. Deeply buried weak layers in the mid snowpack and near the ground still have the potential to wake up and become active with a rapid warm up. While unlikely, releases on these deeply buried weak layers would result in very large avalanches running to valley bottoms. Glide cracks are widespread, active, and best avoided. Low elevation and thin snowpack areas have become isothermal.

Avalanche Problems

Cornices

This time of year the strength of cornices deteriorates rapidly with solar radiation.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Give cornices a wide berth when travelling on or below ridges.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 3 - 6

Persistent Slabs

Rapid warming commonly awakens dormant weak layers deep in the snowpack.

Avoid slopes with glide cracks.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Choose regroup spots carefully.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 3 - 6

Loose Wet

Changes can be rapid, sometimes significant change is possible in a matter of minutes, certainly within an hour or two.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3