Avalanche Forecast

Issued: Apr 5th, 2016 8:00AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs, Loose Wet and Persistent Slabs.

Parks Canada chris gooliaff, Parks Canada

Surface slabs from yesterday's storm overlie a warm, Spring snowpack. Last night was the first decent freeze at tree-line in several days.

Summary

Weather Forecast

Mainly cloudy today with flurries, freezing levels staying around 1800m, and light to gusting moderate SW winds. More of the same tomorrow, with 5-10cm of snow in total from Tuesday morning to Wednesday night. Things will change dramatically on Thursday, with freezing levels rocketing to 3600m, sunshine, and light winds.

Snowpack Summary

Up to 15cm of snow fell overnight at 1900m. The new snow is insulating a moist snowpack and likely formed new storm slabs in immediate lee areas. The rain at lower elevations prevented a solid crust recovery and the snowpack is isothermal. Multiple crusts in the top meter of the snowpack provide sliding surfaces, especially on solar aspects.

Avalanche Summary

The parade of moist and wet avalanches continued yesterday with the rain. Numerous moist and wet avalanches, both loose and slab, were observed throughout the highway corridor. These slides are pushing very heavy, dense debris and are digging down to ground by the time they reach the valley. A moist size 3 was observed from Perley Rock yesterday.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs
Storms slabs will have formed overnight with the new snow and winds. Given the warm temp's, they will be stubborn to trigger, but be looking for them as you head onto the lee side of ridges.
Be cautious as you transition into wind affected terrain.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet
Lower elevation tests show an isothermal snowpack. While temp's have dropped overnight, brief glimpses of a strong April sun can be enough to trigger loose avalanches. These loose slides have the potential to entrain a lot of mass and be destructive.
Use extra caution on solar slopes or if the snow is moist or wet.Be alert to conditions that change with elevation.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Step-down avalanche potential exists with the many crusts buried in the upper metre. Tests on these crusts indicate that it will likely take a heavy load to trigger them, like a cornice fall or another avalanche. Expect large avalanches if they move!
Use extra caution on slopes if the snow is moist or wet.Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 6th, 2016 8:00AM