Avalanche Forecast

Issued: Dec 18th, 2016 4:32PM

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

Avalanche Canada conrad janzen, Avalanche Canada

The hazard continues to increase with the strong winds and some new snow on the way. More conservative terrain choices will be the best bet for the next day or two until the snowpack has a chance to stabilize.

Summary

Weather Forecast

Warmer temperatures and 10cm of new snow are forecasted to arrive on Sunday night and into Monday. This approaching system is expected to arrive with moderate to strong West winds at higher elevations.

Snowpack Summary

Moderate to strong winds are creating widespread wind slabs above tree line. The low elevation snowpack in the Little Yoho region is shallow and facetted with a total depth of <100 cm up to 2000 m elevation. Above that, the snow becomes much deeper and stronger with recent test results showing no significant weak layers or shears in the snowpack.

Avalanche Summary

Several natural and skier triggered wind slab avalanches up to size 1.5 were observed and reported on Sunday. Loose snow avalanches up to size 1.5 are occurring in steep terrain with the strong winds. Some of these avalanches are traveling further than expected because of the weak faceted snowpack acting as marbles near the ground.

Confidence

Forecast snowfall amounts are uncertain on Monday

Problems

Loose Dry

An icon showing Loose Dry

The surface snow is facetted and weak allowing for wind triggered large sluffs in steep terrain. These sluffs are picking up mass and running far. Pay attention to terrain traps where snow can accumulate into deeper deposits.

  • The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.
  • Be aware of party members below you that may be exposed to your sluffs.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs

Strong winds have added to the wind slab problem. By now the alpine snowpack is highly variable ranging from impenetrable hard slab to loose faceted snow. Probe often to determine the extent of the wind slabs and avoid them in steep terrain.

  • Use caution in lee areas. Recent wind loading have created wind slabs.
  • Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 19th, 2016 4:00PM