Avalanche Forecast

Issued: Apr 19th, 2022 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

A bit of new snow has introduced manageable wind slab and wet loose hazards in the areas it fell. Avalanche activity is unlikely where it didn't. The greatest potential is in the south and west of the region.

Summary

Confidence

Moderate -

Weather Forecast

TUESDAY NIGHT: Mainly cloudy with continuing isolated flurries and a further trace of new snow. Light east or southeast winds.

WEDNESDAY: Cloud diminishing over the day. Light east or southeast winds. Treeline high temperatures around -3.

THURSDAY: A mix of sun and cloud. Light southeast winds shifting southwest. Treeline high temperatures around -1.

FRIDAY: A mix of sun and cloud. Light southwest winds. Treeline high temperatures around -1.

Avalanche Summary

One recent cornice fall that did manage to trigger a slab was reported from a flight over the Telkwa range on Friday. On Saturday a few small loose dry avalanches were observed in steep, solar, rocky terrain. Otherwise, no new avalanches have been reported in the past few days.

On Thursday, explosives triggered wind slabs up to size 2 on south-south east aspects. On Wednesday, glacial icefall (serac) triggered a large persistent slab avalanche (size 3). This avalanche occurred on a northeast aspect in the alpine and is suspected to have failed on a crust from early April. This avalanche was only possible with an extremely large load and is not suggestive of general conditions in the region as a whole.

Looking forward, areas that received a bit of snow Monday/Tuesday will have small surface instabilities (small wind slabs, wet loose potential) to manage on Wednesday, particularly with solar warming.

Snowpack Summary

Very light new snow amounts, up to about 10 cm in the Howsons, have landed on heavily wind-affected surfaces in exposed terrain, the product of an intense wind event early last week. In sheltered areas, the flurries may have added to limited stashes of soft, potentially faceted snow. After daytime warming and a subsequent freeze on Wednesday, it will add to the growing tally of crusts on solar aspects. A widespread melt-freeze crust can be found 20 to 50 cm deep in most areas, and up to 80 cm in the snowiest parts of the region. This crust is near the surface below 1200 m.

Terrain and Travel

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

Cornices

An icon showing Cornices

Cornices are large this time of year and were likely weakened by recent cold temperatures. Exposure to cornices should be minimized, especially during periods of warm temperatures or strong sun. Give them a wide berth when you are travelling on ridge lines and avoid overhead exposure to large cornices. 

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Loose Wet

An icon showing Loose Wet

In areas with a bit of new snow, small wet loose avalanches will be possible on steep, sun-exposed slopes in the afternoon. Manage your exposure to steep solar slopes if the surface becomes moist or wet.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 1.5

Wind Slabs

An icon showing Wind Slabs

Light new snow amounts and elevated winds likely formed small new wind slabs to manage in exposed terrain. This likely only affects the southwest part of the region.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Apr 20th, 2022 4:00PM