Avalanche Forecast

Issued: Apr 27th, 2017 8:00AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs, Loose Wet and Cornices.

andrew jones, Parks Canada

Glacier.

Large glide cracks are beginning to fail with ongoing spring conditions. Glide failures can be difficult to predict and slopes with open cracks should be avoided.

Summary

Weather Forecast

A mix of sun and cloud today as an upper level trough will bring scattered flurries to the alpine today with trace amounts of accumulation. Freezing levels rise to 1700m this afternoon. Ridge winds from the west, 15km/h.

Snowpack Summary

High elevation N aspects still hold a winter snowpack with surface windslab that may be sensitive to human triggering given the right location. On solar aspects expect temp crusts and sun crusts in morning and moist surface as the day warms. Field trip yesterday showed little recovery in surface crusts until 1900m. Unsupportive snow below 1700m.

Avalanche Summary

A size 3.5 natural glide crack avalanche adjacent to the highway released during the overnight period. No other new activity has been observed.

Confidence

Problems

Wind Slabs

Expect to find pockets of windslab on high elevation N aspects formed by recent S-SW winds. Skiers reported triggering windslab to size 2 on Sunday.

Use caution in lee areas. Recent wind loading has created wind slabs.Watch for whumpfing, hollow sounds, and shooting cracks.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Poor overnight crust recovery at low elevations last night. Surface crust breakdown can be expected with daytime warming. Wet slides may occur later in the day.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Cornices are huge and hanging over alpine lee slopes in many places. Daytime warming may promote failure of these large triggers. Cornice failure may wake persistent weak layers.

Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.Pay attention to overhead hazards like cornices which could trigger slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 28th, 2017 8:00AM