Avalanche Forecast

Issued: Jan 4th, 2017 4:26PM

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

Avalanche Canada cam_c, Avalanche Canada

Persistent weaknesses deeper in snowpack still can't be totally trusted. Approach big open slopes with caution, especially in shallow snowpack areas.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

THURSDAY: Mainly cloudy with isolated flurries bringing trace accumulations, light southwesterly winds, alpine temperature around -12.FRIDAY: Cloudy with sunny periods and isolated flurries bringing trace amounts of fresh snow, light southwesterly winds, alpine temperature around -15.SATURDAY: Cloudy with sunny periods, light southerly winds, alpine temperature around -10.

Avalanche Summary

Reports from Monday and Tuesday were limited to a few Size 1-2 wind slab avalanches triggered naturally and by explosives. Wind slabs may remain reactive to human triggers in specific areas, such as the immediately lee of ridges and sun-exposed slopes.

Snowpack Summary

Surface hoar is growing and the upper snowpack is faceting. In exposed areas at all elevations, recent winds have resulted in scouring, hard wind slabs, and thicker reactive wind slabs in unusual places as the winds shifted from west to northeast. Continued moderate variable winds have been keeping wind-slabs fresh and touchy in some areas and sun-exposure is likely making the wind slabs extra touchy on south-facing slopes. Facets and/or surface hoar buried mid-December has been giving hard and broken or no results in snowpack tests where it is down close to a metre. However, recent snowpack tests in a shallower area, gave moderate sudden planar results on this persistent weakness where it was found as surface hoar down 20-30 cm. This suggests that the primary concern for persistent slab avalanches is in shallow snowpack areas; however, the potential for step-down avalanches remains where it is deeper. The lower snowpack is well bonded and features a thick rain crust near the ground.

Problems

Wind Slabs

An icon showing Wind Slabs
Weak wind slabs are lurking below ridgecrests and behind terrain breaks in exposed terrain on all aspects.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.Avoid travelling in areas that have been reverse loaded by winds.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
Surface hoar and/or facets buried mid-December remains a concern in shallow snowpack areas.
Be aware of the potential for large avalanches due to the presence of buried weak layers.Dig down to find and test weak layers before committing to a line.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Jan 5th, 2017 2:00PM