Avalanche Forecast

Issued: Apr 19th, 2022 4:00PM

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

Avalanche Canada TRettie, Avalanche Canada

Carefully assess the wind slab hazard as you gain elevation. Limit exposure to slopes with cornices above.

Summary

Confidence

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

Weather Forecast

Tuesday night: Possibility of light flurries bringing trace amounts of new snow with moderate west winds. Low of -8 at 1600 m.

 

WEDNESDAY: A mix of sun and cloud with light flurries bringing trace amounts of new snow and light southeast winds. Freezing levels rising to 1800 m.

THURSDAY: A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Light south winds and freezing levels rising to 2000 m.

Friday: A mix of sun and cloud with no new snow expected. Light west wind and freezing level around 2000 m.

Avalanche Summary

No new avalanches were reported on Monday in the Region.

Reports over the last week documented large cornice falls in alpine terrain, some of which have triggered large slab avalanches (size 2-2.5) on the slopes below. The most avalanche activity has been noted around Valemont and Blue River. 

Snowpack Summary

10 to 20 cm of new snow overlies old wind effected surfaces and a crust on solar aspects. Below this a melt-freeze crust can be found down up to 40 cm on all aspects to 2000 m and mountain tops on solar aspects. Moist snow will likely be observed on solar aspects as the sun comes out.

Another prominent crust layer is found 40-70 cm deep.

Cornices are very large and exposure to slopes beneath them should be minimized, especially if the weather is sunny, warm, or windy. The snowpack deteriorates rapidly at lower elevations.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Avoid sun exposed slopes, especially if snow surface is moist or wet.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs have formed at treeline and above. These wind slabs will likely not bond well to the surfaces below.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices may be weak and reactive to human triggers. Give them a wide berth when travelling on ridges. They are a significant hazard alone and may produce large slab avalanches as they fall onto the slope below. Cornice falls are more likely when the weather is sunny, warm, or windy.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Loose Wet

An icon showing Loose Wet

wet loose avalanches will likely occur in steep terrain as the sun comes out.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

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