Avalanche Forecast

Issued: Dec 7th, 2014 4:00PM

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

a.l. horton, Parks Canada

Jasper.

A storm is approaching and is forecast to hit the region on tuesday and intensify into Wednesday. Conditions will deteriorate rapidly.

Summary

Weather Forecast

Snow will begin Monday evening becoming heavy by Wednesday with accumulations of 30 cm possible. Winds will increase into the moderate range. Temperatures will be warm with the freezing level reaching to 2200 m on Wednesday. Precipitation will likely fall as rain at lower elevations.

Snowpack Summary

Warm temps are reaching into the alpine and are promoting settlement of last week's storm snow. Isolated windslab can be found in exposed areas in the alpine. The main concern is the interface between the settled storm snow and several crusts near the bottom of the snowpack. This interface is producing widespread whumphing at treeline.

Avalanche Summary

No field patrols today.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Wednesday

Problems

Persistent Slabs

Storm snow has evolved into a persistent slab mainly around treeline and sheltered alpine slopes. Widespread whumphing in open treeline areas. Propagation from whumphing is possible on steep unsupported slopes.

Assess start zones carefully and use safe travel techniques.Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

These slabs are found on exposed slopes and produced moderate to hard test results with failures in the facet layer near the bottom of the snowpack.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 8th, 2014 4:00PM