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Cariboos Avalanche Forecast

Jan 14th, 2020 5:00PM

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

Stay warm, navigate around wind slabs, and be cautious of steep open slopes around treeline.

Summary

Confidence

Moderate - Uncertainty is due to limitations in the field data.

Weather Forecast

TUESDAY NIGHT: Clear, light wind from the southwest, alpine temperatures drop to -38 C.

WEDNESDAY: Sunny, light wind from the south, alpine high temperatures around -30 C.

THURSDAY: Mix of sun and cloud with some isolated flurries and 5-15 cm of low density snow, moderate wind from the south, alpine high temperatures around -20 C.

FRIDAY: Mix of sun and cloud with some isolated flurries and 5-10 cm of low density snow, light wind from the southwest, alpine high temperatures around -17 C.

Avalanche Summary

There have been limited field observations recently, but enough to suggest the persistent slab avalanche problem remains a concern. A large persistent slab avalanche was triggered by a rider in the neighbouring Clemina area on Friday (see the MIN report) and riders on Belle Mountain near McBride reported whumpfing in south facing terrain at treeline on the weekend. Some of these older MIN reports provide helpful photos of slopes where this layer has been a problem (here, here, and here).

Snowpack Summary

As cold arctic air settles over the region expect wind slabs in unusual places due to recent valley winds from the north, while sheltered areas still have 10-30 cm of soft powder. The main concern is a layer of surface hoar that formed in late December, which is now buried 60-120 cm deep throughout the region. This layer is most likely found on sheltered slopes at and below treeline. Reports suggest the reactivity of layer is variable, as on some slopes it is well bonded while on other slopes it is still reactive.

Terrain and Travel

  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • Be careful as you transition into wind affected terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible-Likely

Expected Size

1 - 2

Watch for areas where the low density snow has been blown into into unstable wind slabs.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Possible

Expected Size

2 - 2.5

A concerning layer of surface hoar buried 60-120 cm below the surface may still be reactive to human triggering on certain slopes. The challenge is determining which slopes, meaning steep open slopes at lower elevations should be approached with caution.

Aspects:

All aspects.

Elevations:

Treeline, Below Treeline.

Valid until: Jan 15th, 2020 5:00PM