Avalanche Forecast

Issued: Feb 14th, 2016 7:38AM

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 rbuhler, Avalanche Canada

Lingering wind slabs and large weak cornices are expected to be reactive to human-triggering on Monday.  Use increased caution in wind affected terrain.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Light snowfall is expected Sunday overnight before a weak ridge of high pressure dries things out Monday morning. A substantial storm system is then expected to reach the south coast on Monday afternoon or evening. 5-10cm is expected Sunday overnight with freezing levels around 1400m and moderate southwest winds in the alpine. 5-10cm is possible Monday afternoon with freezing progressively climbing to around 1800m by Monday night. Another 20-40cm is forecast for Monday overnight with strong southwest winds in the alpine. Tuesday is forecast to be mainly dry with light alpine winds and afternoon freezing levels around 1500m. A weak storm system is forecast for Wednesday with freezing levels around 1800m.

Avalanche Summary

On Saturday, ski cutting produced size 1-1.5 soft slab avalanches up to 30cm thick in lee and cross loaded features in the alpine and at treeline. Explosives released cornices size 1-2 in the alpine. Rain-soaked lower elevations are unlikely to see much in the way of avalanche activity, but wind slab avalanches will continue to be reactive to human-triggering at higher elevations with ongoing snowfall and wind continuing overnight Sunday. Cornices are reported to large and fragile, and may fail under the weight of a person.

Snowpack Summary

Recent warm temperatures left us with moist snow up to around 1800 metres. Subsequent cooling has left new crusts in many areas. Wind slabs are forming at higher elevations. Cornices are reported to be huge and collapse has become more likely with additional loading and high freezing levels. About 50-90cm below the surface, you'll likely find a rain crust which formed on January 28th. This crust is widespread and exists up to about 2100m. Where it still exists, the mid-January surface hoar layer may be found between 130 and 200 cm below the surface. The combination of warm temperatures and subsequent gradual cooling is making avalanches failing on these deeper layers unlikely.

Problems

Wind Slabs

An icon showing Wind Slabs
New storm slabs have developed in steep, higher elevation terrain in response to loading from new snow and wind over the weekend.
Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Looming cornices could collapse, especially during storms or during warm weather.  The weight of a person may be enough to cause a cornice failure.
Pay attention to overhead hazards like cornices.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 15th, 2016 2:00PM

Login