Avalanche Forecast

Issued: Feb 20th, 2016 8:31AM

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

Avalanche Canada bcorrigan, Avalanche Canada

New wind slabs have formed in the alpine and at tree line. Cornices continue to grow with new snow and wind.

Summary

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

A short intense pulse of moisture brought 5 to 15cm of snow Friday night.  Gradual clearing should give mostly clear skies on during the day on Sunday. On Monday afternoon night the region may see light flurries, with clearing on Tuesday and through the rest of the week.. Ridgetop winds are forecast to be light to moderate from the southwest with freezing levels rising during the day and falling to valley bottoms at night.

Avalanche Summary

Avalanche observations for the region have been extremely limited, mostly due to stormy weather. New snow and wind on Friday night will likely promote a round of wind slab activity in high elevation lee terrain.

Snowpack Summary

New snow and wind on Friday night will have formed new wind slabs in lee terrain at treeline and in the alpine. Up to 15cm of precipitation fell Friday night.  In addition, the stormy weather has encouraged new cornice growth. These cornices may rbe huge and unsupported. About 30-50cm below the surface you may find a melt freeze crust which formed during the 2nd week of February. At the same interface, you may also find surface hoar which most likely exists on high, north facing terrain. Recent rain and warm temperatures at lower elevations have likely flushed out this weakness in most areas; however, continued reactivity may exist in high elevation terrain above the recent rain line. West of the divide, a layer of buried surface hoar can be found between 70 and 90cm below the surface. Recent reports suggest this layer has become less of a concern.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and wind from Friday night will form fresh and reactive wind slabs at treeline and in the alpine. The new snow may also hide wind slabs formed earlier in the week.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be careful with wind loaded pockets on steep slopes below ridge crests.>Assess start zones carefully and use safe travel techniques.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Recent storms have encouraged cornice development. Large and unstable cornices may be destructive by themselves, but could also act as a trigger for an avalanche on the slope below.
Give cornices a wide berth when travelling on or below ridges.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 21st, 2016 2:00PM