Avalanche Forecast

Issued: Dec 29th, 2018 4:28PM

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

mbender, Avalanche Canada

Kootenay Boundary.

New snow and wind over the past 36 hours has created a touchy storm slab problem. This will require a few days to settle and stabilize as we head into a more stable weather pattern to end the weekend.

Summary

Confidence

Moderate - The weather pattern is stable

Weather Forecast

SATURDAY NIGHT: Flurries, accumulation 5-10cm / Moderate west and northwest wind / Alpine temperature -8 CSUNDAY: Mostly cloudy with sunny breaks / Moderate northwest wind / Alpine temperature -7 C MONDAY: Mix of sun and cloud / Light north wind / Alpine temperature -9 CTUESDAY: Mix of sun and cloud / Light west wind / Alpine Temperature -6

Avalanche Summary

Recent reports indicate widespread thin storm slab avalanche activity size 1-1.5 that were 15cm deep with a some avalanches running to size 2 where thicker wind deposits existed (up to 40 cm). These were reported as explosives triggered, naturally triggered and some skier controlled.

Snowpack Summary

20-40 cm of snow sits on a thin sun crust on southerly aspects and small feathery surface hoar in sheltered areas.Beneath this, around 50 to 100 cm of snow is poorly bonded to a rain crust and a weak layer of feathery surface hoar and sugary facets. Although there has not been a reported avalanche on this layer for about a week, snowpack test results tell us that it is still possible to trigger. It is best to remain conservative and travel cautiously with this layer in the snowpack.The lower snowpack is well-settled.

Problems

Storm Slabs

15-30cm of new snow has accumulated over the past 36 hours to create a touchy storm slab. Southwest winds have created deeper deposits in lee terrain in the alpine and tree line.

Be cautious as you transition into wind affected terrain.New snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

A weak layer buried around 50 to 100 cm is still the main concern. Although avalanche activity has been quiet for the past week, the widespread nature of the layer and snowpack test results suggest that it is still a layer to be concerned about.

Choose low-angle terrain without overhead exposure and watch for clues of instability.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 30th, 2018 2:00PM