Avalanche Forecast

Issued: Apr 28th, 2014 4:00PM

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

garth lemke, Parks Canada

Jasper.

The avalanche danger is Low as long as the melt freeze crust remains intact. The danger will rise rapidly as the crust deteriorates with sun exposure and daytime heating. Freezing levels are to rise dramatically Wednesday and Thursday.

Summary

Weather Forecast

Freeze-thaw conditions continue. Tuesday will be mainly sunny and slightly warmer temperatures as a result. Wednesday and Thursday will be sun and freezing levels rising to 3500m.

Snowpack Summary

There is rain crust from the valley bottom to 2,350m and a sun crust into Alpine on solar aspects. Settled wind slabs are on NE aspects from 2,000 m to the alpine. Moist and wet snow exists below the crust extending into the alpine on solar aspects. The mid-pack is solid on North aspects. Large and ominous cornices.

Avalanche Summary

Several loose wet size 2 noted on Mt sask at 2100-2500m stopping before the river. One size 2 loose wet off boundary peak. Cornice failure peak across sunwapta station E aspect initiated nothing. Dated report sometime before Saturday from Cirrus creek size 3 slab.

Confidence

The weather pattern is stable on Tuesday

Problems

Loose Wet

Travel early before the heat of the day, and avoid big slopes in the afternoon.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Slabs that rest on the April 22 crust have not been reactive lately. It is still possible to trigger these slabs on steep terrain below ridgelines or convex features.

Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

Cornice failures or triggering from thin spots have the potential to initiate deep avalanches. Depending on aspect, these could be a wet or dry slab characteristic.

Pay attention to overhead hazards like cornices.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 29th, 2014 4:00PM