Avalanche Forecast

Issued: Jan 11th, 2019 4:22PM

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

Avalanche Canada dsaly, Avalanche Canada

How warm will it get? A rapidly warming snowpack can quickly lose strength and stress buried instabilities. Best to choose conservative terrain and be aware that conditions may deteriorate through the day limiting your exit plans.

Summary

Confidence

Low - Freezing levels are uncertain

Weather Forecast

FRIDAY NIGHT: Mostly cloudy, no precipitation. Light south wind. Freezing level reaching 1500 m.SATURDAY: Cloudy with sunny periods. Light south wind. Alpine temps reaching +3C, temperature inversion, freezing level rising above 2000 m.SUNDAY: Mix of sun and cloud. Light southwest wind. Alpine temps reaching +6C, temperature inversion, freezing level above 2500 m.MONDAY: Sunny with cloudy periods. Light southwest wind. Alpine temps reaching +4C, temperature inversion, freezing level above 2000 m.More details can be found in the Mountain Weather Forecast.

Avalanche Summary

On Thursday, explosives triggered storm slab avalanches to size 2 and skier traffic triggered size 1-2 storm slabs. These avalanches are reported to have failed within the most recent 20-30 cm storm snow although a few reports suggest some failures on North aspects down 50-60 cm representing accumulated snowfall since December 31. On Wednesday on Mt Kirkup near Red Mountain, a backcountry skier was caught in a avalanche, a storm slab is suspected to have been triggered. The same day, natural avalanches to size 2 were reported around the Whitewater area. Through the day, explosives triggered storm slab avalanches to size 2 and ski cuts triggered storm slab avalanches to size 1.5. Several small wind slabs were triggered by people on Monday on north to north-east aspects near treeline. On Sunday, several explosives-triggered avalanches to size 2 were reported in the region at or near treeline on all aspects.

Snowpack Summary

On Thursday, pin wheeling and tree bombs were noted with warming temperatures through the day. Surface snow became moist to 1700 m. At higher elevations, strong southerly winds have redistributed recent storm snow creating variable storm slabs and wind slabs. Wind slabs were observed at all elevations on Monday and may be hidden under the most recent snowfall. Isolated layers of surface hoar and or crusts may be found in the upper snowpack. A weak layer buried early December is down 60-120 cm in the alpine and treeline elevations. It consists of a rain crust, surface hoar, and facets (sugary snow). Professionals are continuing to monitor this interface and although the likelihood of triggering has gone down, if triggered this weak layer has the potential to produce large avalanches. This layer is most likely to be triggered from thin, rocky areas with a variable snowpack or with a large load, like cornice fall.A major input of heat into the snowpack can stress deeper instabilities and buried weak layers may be activated. Use caution as the snowpack responds to the initial punch of rapid warming and spiking freezing levels.

Problems

Loose Wet

An icon showing Loose Wet
A major input of heat into the snowpack can stress deeper instabilities and activate buried weak layers. Use caution as the snowpack responds to the initial punch of rapid warming and spiking freezing levels.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs
Storm slabs have developed with recent snow and southerly winds. Deeper and more sensitive deposits of snow will be found in wind-loaded terrain: under cornices and roll-overs, cross-loaded areas, and lee terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 12th, 2019 2:00PM