Avalanche Forecast

Issued: Feb 18th, 2017 4:00PM

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

Avalanche Canada stephen holeczi, Avalanche Canada

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Little Yoho.

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Potential for large avalanches persist. Conservative route choices remain the theme of the day.

Summary

Weather Forecast

5-10 cm is possible on Sunday at higher elevations with freezing levels to 1700m and light SW winds. Another system Tuesday may bring 10 more cm if the forecast holds true...

Snowpack Summary

40-60 cm of snow in the past week combined with mod SW winds created windslabs on lee and crossloaded features. This rests on hard windslabs at treeline and above which overly a structurally weak mid-pack. Below 1900m a surface crust has formed from the previous rain and warming event on Thursday, and subsequent cooling.

Avalanche Summary

Several avalanches in the BYK region in the past 48 hrs, some stepping down to deep persistent layers and the ground. A rain event on Thursday triggered a loose wet cycle below 1900m in the Field area. With cooling over the last 2 days the natural activity has slowed and no new avalanches were reported in that area Saturday.

Confidence

Intensity of incoming weather systems is uncertain on Sunday

Problems

Persistent Slabs

An icon showing Persistent Slabs

The recent snow has created a thick slab over several weak interfaces in the mid-pack. Dig down to see how the recent storm snow is bonding to the layer below, and choose conservative terrain features. 

  • Use conservative route selection, choose moderate angled and supported terrain with low consequence.
  • Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Recent snow and recent wind has created wind slabs in the alpine, which are slowly losing reactivity due to cooler temperatures.

  • If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 19th, 2017 4:00PM

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