Avalanche Forecast

Issued: Feb 20th, 2016 8:20AM

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

Avalanche Canada esharp, Avalanche Canada

Storm slabs are expected to remain reactive, especially if the sun comes out on solar slopes and on wind loaded features in the alpine.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Tuesday

Weather Forecast

SUNDAY: partly cloudy with flurries starting in the afternoon, up to 5cm expected overnight, moderate southwesterly winds, freezing level of 1200m. MONDAY: lingering flurries with sunny breaks, moderate northeast winds, freezing level of 1000m. TUESDAY: mainly sunny, light variable winds, freezing level of 800m.

Avalanche Summary

Isolated artificially and naturally triggered storm slab, wind slab and cornice avalanches continue to be reported.  Storm slab avalanches are expected to be remain reactive to human-triggering with ongoing wind, especially if the sun pokes out.  Cornices are reported to large and fragile, and may fail under the weight of a person.

Snowpack Summary

40-80cm of settling storm snow overlies a thick melt-freeze crust which extends into the alpine. The snow is reported to be bonding well to the crust and recent avalanches have been failing within the recent storm snow, not on the crust interface. At treeline and below, other crusts may exist in the upper snowpack due to the recently fluctuating freezing levels. Freezing levels on Wednesday climbed to around 2000m and have to fallen to around 1400m. As the freezing level continues to drop, a crust is expected to form at lower elevations. Ongoing southeast through southwest winds have been loading leeward features in the alpine and large cornice development has been reported over the last few days. The weak surface hoar layer from early January can be found down over a meter.  Although triggering this layer has become unlikely it is still reactive in isolated snowpack tests,

Problems

Storm Slabs

An icon showing Storm Slabs
Recent storm slabs continue to be reactive to rider triggers especially on wind loaded slopes. If the sun shines it may have enough punch to trigger natural avalanches.
Avoid freshly wind loaded features. >The new snow will require time to settle and stabilize. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Looming cornices could collapse naturally during the warm weather. The weight of a person may be enough to cause a cornice failure.
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.

Likelihood

Possible

Expected Size

1 - 4

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