Avalanche Forecast

Issued: Apr 1st, 2017 4:00PM

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

Avalanche Canada tim haggarty, Avalanche Canada

A storm has brought new snow and moderate to strong winds to the area. It would be wise to let the snowpack adjust to this change as most inputs over last two months have induced avalanche cycles.

Summary

Weather Forecast

The current storm will have brought up to 10cm of new snow and rain below 1800m by the time it passes late Saturday. The moderate to strong west winds will back off into Sunday however trace amounts will continue to accumulate as temperatures cool. Clearing Monday will bring a cool morning and potentially some solar heating with very light winds.

Snowpack Summary

5 new plus 10 to 20cm of recent snow sits on a well settled mid-pack. In shallow areas (Field ice climbs) the base is weak and facetted. Shears persist on this facet interface. In deeper areas (Little Yoho Valley), the deep weak layers are less of a concern. Expect buried sun crust on solar aspects, temperature crusts BTL, and wet snow below 1800m,

Avalanche Summary

Loose wet activity that was seen on Friday likely continued to a lesser degree today with rain below 1800m. Although no direct observations were made in the Little Yoho Region today, small new windslabs at alpine and treeline elevations were reacting to skiers in the Banff region today.

Confidence

Timing or intensity of solar radiation is uncertain on Monday

Problems

Persistent Slabs

An icon showing Persistent Slabs

The snowpack is stabilizing after the last avalanche cycle, and now we are left with a low probability, high consequence problem. Natural avalanches have mostly ceased, but triggering is still possible - especially from large loads like cornices.

  • Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Wind Slabs

An icon showing Wind Slabs

Fragile new cornice growth and small fresh windslabs have formed with the recent storm.

  • Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 2nd, 2017 4:00PM