Avalanche Forecast
Issued: Feb 19th, 2021 4:00PM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeGradually accumulating new snow combined with moderate to strong southwest winds Friday night through Saturday are expected to continue to promote wind slab development.
Summary
Confidence
Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.
Weather Forecast
FRIDAY Night: Cloudy with flurries, accumulation 3-8 cm, moderate southwest wind, alpine temperature -9 C.
SATURDAY: Cloudy with flurries, accumulation 2-5 cm, moderate to strong southwest wind, alpine temperature -8 C.
SUNDAY: Cloudy with snowfall, accumulation 10 to 15 cm, strong southwest wind, alpine temperature -4 C.
MONDAY: Cloudy with flurries, accumulation 2 to 5 cm, light west wind, alpine temperature 8 C.
Avalanche Summary
No recent avalanche observations were noted. Avalanche activity is expected to increase as new snow and strong wind impact the region.
Snowpack Summary
Stormy conditions return to the region through 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.
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
Expected Size
Valid until: Feb 20th, 2021 4:00PM