Avalanche Forecast
Issued: Feb 17th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
mconlan,
Avalanche Canada
Stormy conditions are returning to the region. New snow likely won't bond well to the surfaces beneath it, requiring a conservative mindset.
Summary
Confidence
Moderate - Uncertainty is due to the track & intensity of the incoming weather system.
Weather Forecast
WEDNESDAY NIGHT: Cloudy with light snowfall, accumulation 2 to 5 cm, 40 km/h southwest wind, alpine temperature -9 C.
THURSDAY: Cloudy with light snowfall, accumulation 2 to 5 cm, 30 km/h south wind, alpine temperature -7 C.
FRIDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 40 to 50 km/h south wind, alpine temperature -6 C.
SATURDAY: Cloudy with snowfall, accumulation 5 to 15 cm, 50 km/h south wind, alpine temperature -10 C.
Avalanche Summary
No recent avalanche observations were noted. Avalanche activity is expected to increase as new snow and strong wind impact the region. As the snow accumulates, dialing back your terrain choices is the prudent choice.
Snowpack Summary
Stormy conditions return to the region on Thursday and into the weekend. The snow is forecast to fall with strong south wind, which should rapidly form new wind slabs in exposed terrain. As the snow accumulates into Friday, widespread storm slabs are expected to develop. The snow will overly 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.
- Dial back your terrain choices if you are seeing more than 20 cm of new snow.
Problems
Wind Slabs
New wind and storm slabs are expected to form as the wind blows and new snow falls. Wind slabs are expected to form first in exposed terrain, followed by widespread storm slab development as snow continues to accumulate into Friday. 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
Expected Size
Valid until: Feb 19th, 2021 4:00PM
