Avalanche Forecast

Issued: Dec 15th, 2013 8:00AM

The alpine rating is high, 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.

Avoid avalanche terrain during periods of heavy loading from new snow and wind.

Summary

Weather Forecast

Light snow is forecast today, with around 5 cm of accumulation. Freezing levels will rise to around 1300m. Ridge top winds continue to be SW 40 gusting to 70. Only trace amounts of snow are forecast for tomorrow, with a return to light snow on Tuesday. Temperatures will slowly fall over the forecast period.

Snowpack Summary

40-50cm 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 rapidly settling into a slab with warm temperatures and moderate to strong winds. The November 28 surface hoar is down around 60-80cm.

Avalanche Summary

We observed a small natural avalanche cycle along the highway corridor yesterday. The majority of the avalanches were size 1.5 to 2.5 from all aspects depositing snow into runnouts. Two size 3.0 avalanches were observed both east and west of Rogers Pass.

Confidence

Due to the number of field observations

Problems

Storm Slabs

Over 50cm of storm snow has created soft slabs. Use caution in terrain over 30 degrees. Small avalanches could trigger deeper instabilities.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

Watch for soft slabs on lee features at and above tree-line. Large amounts of snow are being transported by moderate to strong SW winds.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 16th, 2013 8:00AM