Avalog Join
Archived

Avalanche Forecast

Feb 20th, 2021–Feb 22nd, 2021
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold

Regions: Yukon.

There is uncertainty with how much snow is forecast to fall Saturday night and Sunday. Expect avalanche danger to rise through the day Sunday as snow accumulates and wind blows moderate to strong from the southwest.

Confidence

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.

Weather Forecast

SATURDAY Night: Cloudy with flurries, accumulation 5-10 cm, moderate to strong southwest wind, alpine temperature -8 C.

SUNDAY: Cloudy with snowfall, accumulation 5-10 cm, moderate to strong southwest wind, alpine temperature -6 C.

MONDAY: Mainly cloudy with flurries, accumulation 2 to 5 cm, light west wind, alpine temperature -8 C.

TUESDAY: Mix of sun and cloud, light southwest wind, alpine temperature -13 C.

Avalanche Summary

Most recent reports show natural and skier triggered wind slab avalanches to size 1 and 1.5 in the alpine and treeline on Saturday as outlined in this MIN post here.

Snowpack Summary

Expect stormy conditions through the end of the weekend. The snow is forecast to fall with strong southerly wind, which should rapidly form new wind slabs in exposed terrain. As the snow accumulates widespread storm and wind slabs are expected to develop. The snow will overlie heavily wind affected and faceted surfaces in exposed terrain and perhaps a weak layer of surface hoar in sheltered areas, as found here.

The lower snowpack is strong around White Pass, but inland areas like the Wheaton Valley likely have a thinner and weaker structure.

Terrain and Travel

  • Watch for avalanche hazard to increase throughout the day.
  • Wind slabs are most reactive during their formation.
  • Closely monitor how the new snow is bonding to the old surface.
  • Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.

Avalanche Problems

Wind Slabs

New wind and storm slabs are expected to form as the wind blows and new snow falls. These slabs may not bond well to the surfaces beneath it, being composed of hard wind-affected snow, weak surface facets, and perhaps weak surface hoar in sheltered areas.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2