Avalanche Forecast

Issued: Apr 24th, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

Limited field observations have been made in the past week.

Make observations as you travel and be on the lookout for signs that suggest unstable snow. Expect snow conditions to change quickly with elevation, aspect, and time of day.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

SUNDAY NIGHT: Cloudy with a mix of rain and snow, up to 5 cm of new snow accumulation at higher elevations. Freezing level lowering to 900 m. Light to moderate southerly winds.

MONDAY: Mainly cloudy with isolated flurries. Freezing level rising to 1300 m. Light to moderate southerly winds. 

TUESDAY: A mix of sun and cloud. Freezing level rising to 1300 m. Light southerly winds.

WEDNESDAY: Partially cloudy. Freezing level rising to 1500 m. Light southwesterly winds.

Avalanche Summary

On Saturday, numerous wet loose avalanches were observed from steep terrain at treeline and below (size 1-1.5). A few glide slabs released from rocky terrain below treeline (size 2).

In the north of the region on Saturday, a few natural wind slabs were reported in the alpine, failing in lee features directly below ridgelines (size 1-1.5). 

Looking forward to Monday, reactive wind slabs may still exist in lee terrain features in the alpine. Wet avalanche activity is likely at lower elevations and on steep solar aspects with a weak overnight refreeze and the potential for rain or strong solar radiation during the day. 

Snowpack Summary

Recent snowfall and southerly winds are expected to have created pockets of wind slabs in lee areas in the alpine. This 10-30 cm of new snow is expected to bond poorly to heavily wind-affected and facetted surfaces, the product of strong outflow wind and cold temperatures early last week. A crust can be found on steep solar aspects. Below 1200 m, rain and warm temperatures are expected to have broken down the surface crust and the snowpack may become isothermal. The mid and lower snowpack is well bonded with no concerning weak layers. 

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent snowfall and southerly winds have formed wind slabs in lee areas in the alpine. 

Use caution entering lee terrain features below ridges. The snow could slide easily where it rests on a hard melt-freeze crust or faceted snow. 

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Rain at lower elevations may cause the snowpack to become isothermal, producing wet loose activity on steep slopes at treeline and below. Glide slab activity has been noted on steep rock slabs and grassy slopes, avoid travelling on or below slopes with large glide cracks.

If the sun comes out on Monday, wet loose activity is likely on steep solar aspects at all elevations, especially where dry snow is seeing the sun for the first time.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Cornices

An icon showing Cornices

Cornices are large this time of year and may be weak from warm temperatures. Give them a wide berth when you are travelling on ridgelines and avoid overhead exposure to large cornices. 

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Apr 25th, 2022 4:00PM