Avalanche Forecast

Issued: Apr 28th, 2017 7:21AM

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.

chris gooliaff, Parks Canada

Glacier.

Get an early start to your day to take advantage of the frozen snowpack in the morning. It rapidly breaks down and becomes unstable with daytime warming, sunshine, or rain.

Summary

Weather Forecast

Cloudy with sunny periods today, with clearing tonight and freezing levels dropping to valley-bottom. Flurries are expected on Saturday, bringing up to 10cm to the alpine elevations, and freezing levels may rise to 1800m. Flurries will continue on Sunday, with 5cm in the alpine, freezing levels around 1600m, and winds moderate from the west.

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 no recovery in surface crusts due to rain overnight.

Avalanche Summary

A size 3.5 natural glide crack avalanche adjacent to the highway released during Thursday morning. 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.

Watch for whumpfing, hollow sounds, and shooting cracks.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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.

Use extra caution on solar slopes or if the snow is moist or wet.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 29th, 2017 8:00AM