Archived

Avalanche Forecast

Apr 10th, 2012–Apr 11th, 2012

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

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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

Regions: Kananaskis.

With little to no freeze expected overnight and freezing levels near 3600m on Wednesday, avalanche danger will climb rapidly and could hit HIGH on steep solar aspects. Avalanche control on EEOR and Mt. Buller planned for Wednesday at 11:00am

Confidence

Good

Weather Forecast

Freezing levels will stay elevated through the night and spike again on Wednesday to at least 3400m. It is quite possible that there will not be a significant overnight freeze. Winds are expected to be light from the south and temperatures at 3000m will reach +5.

Avalanche Summary

Widespread solar triggered sluffing occurred through the day up to size 2.5, beginning on SE aspects and progressing to S and W aspects. Several large slab avalanches occurred in the alpine on southerly slopes. These slides were in the range of size 2.5 and 3.0, had fracture depths in excess of one meter and wide propagations.

Snowpack Summary

Crusts exist on all aspects at all elevations, except for true north aspects which have crusts below 2400m, and dry snow above. The snowpack is settling rapidly with the very warm temperatures. The deeply buried weak layers of surface hoar and basal facets are responsible for numerous large, destructive avalanches over the past few days. Cornices are large.

Avalanche Problems

Loose Wet

Loose wet slides up to size 2.5 occurred today on solar aspects. These slides were gaining mass and running far in some cases. Pay close attention to terrain that is overhead as you travel and be aware of your regroup spots.

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

Elevations: All elevations.

Likelihood: Very Likely - Certain

Expected Size: 1 - 4

Persistent Slabs

The Feb surface hoar and basal facets are a concern in the snowpack. Solar radiation and large loads, such as cornices, have triggered avalanches up to size 3.5 recently. The spring transition could see more slides stepping down to these layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 7