Avalanche Forecast

Issued: Feb 9th, 2016 7:10AM

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

ccampbell, Avalanche Canada

Purcells.

Warm temperatures and sun-exposure are maintaining an elevated avalanche danger. Keep it conservative until things cool off and the snowpack settles.

Summary

Confidence

High

Weather Forecast

WEDNESDAY: Mainly sunny with increasing cloud throughout the day and light southwesterly winds. A temperature inversion is expected to maintain well above freezing temperatures at treeline and alpine elevations. THURSDAY: Mainly clear and dry with freezing levels dropping to near 2000m and light variable winds. FRIDAY: Light snow possible with freezing levels dropping to valley bottoms and light southwesterly winds.

Avalanche Summary

Reports from Monday include numerous natural wet loose sluffs up to Size 1.5 in response to warm temperatures and direct sun-exposure, limited primarily to steep slopes in the afternoon.

Snowpack Summary

The surface snow is becoming moist and cohesionless, and cornices are getting weak throughout the day with warm temperatures and direct sun-exposure. Strong to extreme winds on Saturday created wind slabs and cornices in many areas, and scoured north and west-facing alpine slopes. The early January surface hoar/ facet layer is typically down 70-90 cm. Recent very large avalanches have been failing on this interface in the north of the region (see avalanche discussion). In general, the lower snowpack below this layer is well settled and strong, apart from some thin snowpack areas where basal facets exist.

Problems

Loose Wet

Strong sunshine and warm temperatures are expected to weaken surface snow layers and cause loose wet avalanches or wet slabs.

Be aware of what is above you at all times.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Wind Slabs

Recently formed wind slabs may still be able to be triggered by the weight of a person. Cornices are likely to be fragile in the hot weather.

Travel on ridges to avoid freshly wind loaded features. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Pay attention to overhead hazards like cornices.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

A deeply buried weak layer can still be triggered in some places, creating very large avalanches. Forecast warming may increase the sensitivity of this problem.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Be cautious around open slopes and convex rolls at and below treeline where buried surface hoar may be preserved. Big alpine features are also suspect.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Feb 10th, 2016 2:00PM