Avalanche Forecast

Issued: Dec 14th, 2013 8:04AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Wind Slabs.

catherine brown, Parks Canada

Glacier.

Avalanche hazard will rise today if forecast strong winds occur. Use caution in avalanche terrain during periods of heavy loading from new snow and wind.

Summary

Weather Forecast

Light snow is forecast today with alpine temperatures around -2 and the freezing level rising to 1400m. Expect ridge top winds to be SW 20 gusting to 80. This weather will continue through Sunday with a break in the precipitation forecast for Monday. Snow is expected to return Tuesday.

Snowpack Summary

45-55cm of storm snow sits over the December 8 surface hoar layer at lower elevations and over variable wind slabs up high. The storm snow is mainly low density with some soft slab developing as temps warm. The November 28 surface hoar layer is down around 60-75cm over a facetted mid-lower snowpack. The Nov 12 surface hoar layer is down 80-110cm.

Avalanche Summary

Yesterday natural avalanches with large powder components occurred. We observed avalanches up to size 2.5 east of Rogers Pass along the highway corridor. The public observed avalanches off the steep north facing terrain off Cheops. Sluffing of the low density surface snow was observed in unsupported terrain, steeper than 35 degrees.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

Soft slabs are forming in over 50 cm of storm snow. Use caution in terrain over 30 degrees. Small avalanches could trigger deeper instabilities. Fast sluffing is likely and will pick up large amounts of snow. Avoid exposure to terrain traps.

Make observations and assess conditions continually as you travel.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

Watch of soft slabs on lee features at and above tree-line. Large amounts of light snow will be transported by SW winds.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 15th, 2013 8:00AM