Archived

Avalanche Forecast

Feb 26th, 2016–Feb 27th, 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

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

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.

Spring like warming by day and colder temperatures at night. The snowpack is gaining strength for most part but large avalanches (up to size3) are still being observed in isolated alpine slopes. Forecasters are avoiding shallow rocky snowpack areas.

Confidence

High

Weather Forecast

The ridge of high pressure will break down and small amounts of precipitation are forecast.Â Cloudy conditions with light flurries for Saturday and the freeze level will rise to 1900 meters.Â Winds will be moderate from the west with gusts up 60km/h.

Avalanche Summary

The warm air and clear skies from the last 2 days have introduced solar heat input and has caused a small loose wet avalanche cycle on solar aspects yesterday and today. The loose wet avalanches in a few cases triggered a size 2 slab on a high south facing alpine feature. Another size 3 avalanche that went to glacier ice was observed today on the NE face of Mount Robertson. It's unclear what the exact trigger was but recent daytime heating and/or cornice failure was the likely culprit.

Snowpack Summary

Spring conditions are beginning to influence the snowpack. Solar and melt-freeze crusts can be found on all solar aspects and temperature crusts to 2100 meters. The upper snowpack has a buried melt-freeze crust, the February 11th crust has not been reactive in snowpack tests but may possibly be responsible for some recent slab avalanche activity. The January 6th facets are still lurking about 60-70cm below the surface and generally showing non results in snowpack tests. The snowpack temperature gradient is showing rounding taking place which indicates strengthening in upper treeline and alpine elevations. Lower treeline and below treeline where the snowpack is less than 100 cm is still weak but semi-supportive because of recent temperature crusts which carry a skier's weight.

Avalanche Problems

Persistent Slabs

The snowpack appears to be gaining strength and we are gradually gaining confidence in bigger terrain in the alpine with cautious analysis of snowpack depth and distribution. Essentially, we encourage the avoidance of steep, rocky & shallow areas

Be aware of the potential for large, deep avalanches.>Avoid steep slopes below cornices.>Avoid thin, rocky or sparsely-treed slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 5

Cornices

Cornices need lots of space and as little exposure time as possible. Keep your up-track well away from recently developed cornices.

Avoid areas with overhead hazard.>Cornices become weak with daytime heating. >

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 4

Wind Slabs

Windslabs from last week are bonding well but there may slabs overlying weaker facetted crystals or atop crusts from early February in isolated locations at treeline and above.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.>

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 3