Avalanche Forecast

Issued: Feb 20th, 2016 4:00PM

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

Max Darrah, Parks Canada

Jasper.

Cool temperatures and minimal precipitation expected over the next few days. Be wary of big steep slopes in the alpine, particularly shallow areas with slab over facets. Human triggering is still possible.

Summary

Weather Forecast

Cooling trend through the weekend, with freezing levels dropping to 900m with good recovery overnight with lows of -15C. Clear skies through the weekend with light to moderate Southwest winds. No new snow on the horizon until Sunday night, with only light flurries amounting to less than 5cm.

Snowpack Summary

Moderate SW winds have built wind slab at tree-line and above. These slabs may be up to 40cm thick. The mid-pack consists of buried wind and persistent slab with a failure plane down 60cm that is producing mostly resistant planar results in tests. In the valley bottom the snowpack is weak and unconsolidated making for tough trail breaking.

Avalanche Summary

No new avalanches observed today.

Confidence

Problems

Wind Slabs

Windslabs appear to be bonding well, however caution is still warranted in immediate lees and cross loaded terrain above treeline.

Caution in lee and cross-loaded terrain near ridge crests.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Persistent weak layers of decomposed surface hoar, facets, and depth hoar can be found in many locations. Although these layers have been dormant lately, careful slope evaluation is essential. Be cautious of shallow areas with slab over facets.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 21st, 2016 4:00PM