Avalanche Forecast

Issued: Dec 29th, 2019 8:00AM

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.

Parks Canada mike smallwood, Parks Canada

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Watch out for wind loaded pockets and avoid areas where the Dec 11th surface hoar has not already been triggered.

Summary

Weather Forecast

A mix of sun and cloud today with an alpine high of -3 and light winds at ridgetop. Freezing levels rising to 1300m. Tomorrow winds pick up to strong from the SW with flurries accumulating to 6cm and temperatures falling. Tuesday the bulk of the storm arrives with up to 40cm and moderate SW winds.

Snowpack Summary

15cm recent new snow on top of surface hoar at treeline and a thin crust on steep solar aspects. The cold temperatures this week have weakened the top 50cm of previous storm snow. Below that it is quite stiff down to the Dec 11th surface hoar (5-12mm) which is now down 90-130cm. Early season crusts still persist in the rounding lower snowpack.

Avalanche Summary

Several natural avalanches since the pre Christmas storm were observed on all aspects running to size 3. Natural activity is now slowing.

Confidence

Intensity of incoming weather systems is uncertain on Tuesday

Problems

Wind Slabs

An icon showing Wind Slabs

15cm of recent snow with moderate S-SW winds have formed slabs in alpine lees. Be alert for cross-loaded features and terrain traps.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs

The surface hoar layer down a meter is well preserved in some areas and human triggering remains possible. Due to the depth of this layer the resulting avalanche would be large.

  • Be wary of slopes that did not previously avalanche.
  • Use caution on open slopes and convex rolls where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Dec 30th, 2019 8:00AM