Avalanche Forecast

Issued: Dec 19th, 2021 4:00PM

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

Avalanche Canada TRettie, Avalanche Canada

Email

Continue to make conservative decisions as the storm snow settles and we learn more about how the early December layer has responded to the new load.

Summary

Confidence

Moderate -

Weather Forecast

Sunday night: some light flurries with light Northwest winds. Low of -22 at 1600m.

MONDAY: no new snow expected. Light Northwest winds becoming strong in the afternoon. High of -18 at 1600m.

TUESDAY: Increasing cloudiness with flurries; 3-5 cm / Strong west wind / High of -15 at 1600m.

Wednesday: Up too 30cm of new snow with moderate Southwest wind. High of -15 at 1600m.

Avalanche Summary

No new avalanches were observed over the weekend.

If you are out in the mountains please consider filling out a Mountain Information Network report.

Snowpack Summary

Up too 20cm of recent new snow has been redistributed by Southwest winds. This has likely created wind slab on North and East facing features. As the wind shifts to the Northwest reverse loading is possible.

The prominent layer within the snow pack is the early December facet/crust combo. This layer generally exists below 1800m and is most concerning in the area west of Blue River.

Another crust layer near the bottom of the snowpack has not produced any recent avalanches but may be possible to trigger by hitting a shallow spot in the snowpack on a large alpine feature.

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slab has formed from Southwest winds. As the wind shifts to the Northwest unusual wind loading could take place.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

A layer of facets can be found above a crust from early December. This facet/crust combo is down 80 to 150cm and is most concerning in the terrain West of Blue River at the treeline elevation.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 20th, 2021 4:00PM