Summary
Confidence
Fair - Freezing levels are uncertain for the entire period
Weather Forecast
Friday: Clouds and a few cm of snow, falling as rain below about 1400 m. Freezing level around 1600 m. Light northerly winds.Saturday: Cloudy with sunny breaks. Light, variable winds. Freezing level around 1500 m.Sunday: Warm, dry and cloudy. Freezing level rising to 1800-2000 m. Light winds, increasing from the SW by evening as a low pressure system approaches.
Avalanche Summary
Recent reports include cornice fall and loose wet avalanches. Full-depth size 2-3 glide avalanches have been releasing on rock slabs.
Snowpack Summary
Rain fell to 2000 m on Wednesday. Ongoing warm temperatures and the rain have caused the surface snowpack layers to become isothermal (at 0 °C), even on north aspects, to about 2100 m. This is expected to have formed a crust in some areas, now covered by a small amount of new snow. Very large cornices are looming. Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. Otherwise, a relatively strong and deep spring snowpack exists, which becomes weak during periods of warm weather or rainfall. A buried crust/surface hoar layer from late March, within the upper 1.5 m of the snowpack, is reported to have gained strength in the Duffey Lake area, but remains a lingering concern.
Problems
Cornices
Mammoth cornices are looming. A cornice fall can act as a heavy trigger for avalanches on the slope below.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Wet loose or slab avalanches are most likely on steep slopes when temperatures are warm, especially at low elevations. Avoid exposure to slopes which are sporting glide cracks.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 13th, 2012 9:00AM
