Avalanche Forecast

Issued: Jan 5th, 2017 4:24PM

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

Avalanche Canada cgarritty, Avalanche Canada

The wind slab problem hasn't disappeared, but you may have trouble seeing it under the skiff of new snow.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

Friday: Cloudy with flurries bringing around 6 cm of new snow. Winds moderate from the south. Alpine temperatures of -8.Saturday: Mainly cloudy with no new snow. Winds light to moderate from the southeast. Alpine temperatures around -5.Sunday: Mainly cloudy with scattered flurries and up to 5 cm of new snow. Winds light gusting to strong from the southeast. Freezing level rising to 800 metres and alpine temperatures to -4.

Avalanche Summary

No new avalanches have been reported, but Tuesdays MIN report of an avalanche involvement in the adjacent South Coast Inland region remains notable for illustrating the heightened consequences of triggering hard wind slab from below the fracture line. Slope cutting as recently as Tuesday was producing Size 1 results in isolated pockets of wind slab. While avalanche reports have begun to dwindle, keep in mind that challenging riding conditions have been keeping some observers out of the mountains

Snowpack Summary

Moderate to extreme winds and cold temperatures over the past few days have left our snow surface a variable mix of soft wind slab, hard wind slab, sastrugi, and faceted snow. 70-100 cm of storm snow lies below this surface, the product of last weeks series of storms. The previously mentioned wind slabs are the primary weakness of concern in our current snowpack. As a product of northerly winds, these wind slabs were reverse loaded into the terrain in our region, forming primarily on southerly slopes in wind-exposed terrain. Local wind patterns, however, allowed slabs to develop on a surprising range of aspects, from west to east. Snowpack tests of various wind slabs continue to produce easy to moderate results, with occasional sudden planar results. Up to 100 cm below the surface lies the Boxing Day interface, which consists of wind affected surfaces, faceted (sugary) snow, or surface hoar. Recent observations suggest the overlying snow is generally well bonded to this interface. The mid-December interface is now down 100-150 cm and is generally considered to be stable in this region. Snowpack layers below this are well bonded.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent strong northerly winds created a widespread wind slab problem in exposed areas on most aspects. A light snowfall on Friday won't add much hazard, but will make slabs more difficult to see.
Anticipate areas of hard wind slab in steep alpine features.Be aware of the potential for hard slabs to fracture above you and propagate widely.Use safe ski cutting techniques before entering steep lines.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 6th, 2017 2:00PM