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Avalanche Forecast

Feb 16th, 2018–Feb 17th, 2018
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: Jasper.

Persistent midpack weaknesses are more pronounced in the northern portion of the forecast zone, with human triggering more likely than the Icefields area.

Weather Forecast

Flurries are expected overnight but with little accumulation resulting as a cold arctic front starts to sweep SW from the icy NE. Clearing expected Sunday and into next week with sunshine and cold nights.

Snowpack Summary

Available snow has been redistributed by strong, variable direction winds. In sheltered Treeline locations, the weak midpack layers are reactive down 50cm. Where snow remains in the Alpine, new wind slabs are reactive to triggering from additional load or solar, and wind-stiffened snow at Treeline is transmitting collapses large distances.

Avalanche Summary

Isolated windslab avalanches were observed today in the Icefields area and loose dry avalanches to size 2 were observed in the Tonquin valley. East, South, and North aspects have formed windslabs and large cornices that have failed in the last 48 hrs in the north portion of the forecast zone.

Confidence

Due to the number of field observations

Avalanche Problems

Wind Slabs

Variable direction, strong upper elevation winds are continuing to create fresh windslabs and stiffen the snow surface well into Treeline locations.
Variable winds have created pockets of wind slab on all aspects.The best powder will be found in sheltered locations at or below treeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5

Persistent Slabs

Whumpfing and cracking are signs of this layer's reactivity. Expect collapses to propagate larger distances with a wind-stiffened snow surface.
Watch for whumpfing, hollow sounds, and shooting cracks.Watch for surface cracking and stiffer surface layers of snow.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Likely

Expected Size: 1 - 2.5

Deep Persistent Slabs

Persistent slabs remain a problem. Areas exposed to large triggers such as cornices or smaller avalanches / sloughing from above are most likely to trigger this midpack weakness.
Pay attention to overhead hazards like cornices which could easily trigger deep slabs.Be wary of slopes that did not previously avalanche

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3.5