Avalanche Forecast

Issued: Dec 8th, 2016 3:56PM

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

Avalanche Canada shorton, Avalanche Canada

Avalanche danger will increase throughout the day. The weather forecast remains uncertain, so consider the avalanche danger to be HIGH if there's more than 30 cm of new snow on Friday.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

FRIDAY: 20-30 cm of new snow, 40-60 km/h southwest winds, treeline temperature at -5.SATURDAY: 20-30 cm of new snow, 20-40 km/h southwest winds, treeline temperature at -3.SUNDAY: 5 cm of new snow, light northwest winds, treeline temperature at -5.

Avalanche Summary

Avalanche activity has declined throughout the week, but the storm snow remained reactive on Wednesday as ski cutting produced a size 1 avalanche on a steep unsupported feature. The likelihood and size of storm slab avalanches will increase throughout the day on Friday with heavy snowfall and strong winds in the forecast.

Snowpack Summary

A heavy pulse of new snow is expected for Friday and Saturday, although the weather forecast models don't agree on how much. By Friday afternoon there may be 20-30 cm of new snow on top of 30-50 cm of settling snow from last Monday. Northeast winds have likely formed thin wind slabs in exposed alpine terrain. A sun crust has been reported on the surface of steep southerly aspects, which may bond poorly with the new snow. A rain crust exists below Monday's storm slab, and recent reports suggest the storm snow may still be poorly bonded to the crust on shady north aspects. Below the crust, the snowpack is settled and strong. Total snowpack depths are 160-200 cm at treeline.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs will build throughout the day with heavy snowfall and wind expected to start Thursday night. Very touchy storm slabs can be expected during periods of rapid loading.
Minimize exposure during periods of heavy loading from new snow and wind.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 2

Valid until: Dec 9th, 2016 2:00PM