Avalanche Forecast

Issued: Jan 22nd, 2015 4:00PM

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.

Avalanche Canada Lisa Paulson, Avalanche Canada

Stay tuned - a significant weather system is forecasted for the weekend bumping up the hazard. We are monitoring the incoming system which will be most intense in the Little Yoho region. Game on...

Summary

Weather Forecast

Another benign day of weather for Friday. We are keeping a close eye on a significant system moving in Friday night through to Sunday with heaviest snow amounts in the Little Yoho region. The winds will be moderate to strong Westerly during the system with temperatures warming on Sunday reaching alpine highs of 0C and rain to 1900 m : (

Snowpack Summary

The snowpack in the Emerald Lake and Mt Field area is about 130cm deep, with the main weakness being the Dec 18 surface hoar down 50 cm. This layer continues to produce moderate to hard results, but the layer is not found in all areas. We suspect some bonding is occurring with this layer, but remain careful. Buried windslabs exist in alpine areas.

Avalanche Summary

No natural avalanches observed, but forecasters on Mt. Field today experienced a large whumph on Wednesday in an open area at 1850m indicating the deeper layers are still reactive to human triggering in some areas.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Buried windslabs in leeward areas can be found up to 25 cm deep. Watch for convex rolls or other areas of wind loading where the snow can be under tension.

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

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

The Dec 18 SH continues to be found 50 cm down, but the layer becoming harder to find, and is slowly bonding to the overlying snow. Regardless, this layer is still present and should be considered carefully

  • Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.
  • Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 23rd, 2015 4:00PM