Avalanche Forecast
Issued: Feb 22nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
MBender,
Avalanche Canada
Give the snow from the weekend some time to settle and bond. There is now a lot of snow available for the wind to distribute into exposed lee terrain. Be aware of wind slab development in the coming days.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
MONDAY Night: Mainly cloudy with flurries, accumulation 1 to 3 cm, light to moderate west switching to northwest wind, alpine temperature -15 C.
TUESDAY: Mix of sun and cloud, light to moderate southwest wind, alpine temperature -13 C.
WEDNESDAY: Cloudy with flurries, accumulation 5 cm, moderate to light south wind, alpine temperature -8 C.
THURSDAY: Cloudy with snowfall Wednesday night into Thursday, accumulation 5-10 cm, moderate to strong south wind, alpine temperature -9 C.
Avalanche Summary
We don't have any official reports of avalanche activity, but since the Highway to White Pass was closed on Monday due to avalanche activity, you can be assured that there was a widespread natural avalanche cycle on Sunday and Sunday night. This MIN report here outlines conditions with the snowfall at the end of the weekend.Â
Snowpack Summary
30-50 cm of new snow falling Saturday night and Sunday will take some time to settle and bond to the old snow surface below. The snow is sitting on heavily wind affected and faceted surfaces in exposed terrain and perhaps a weak layer of surface hoar in sheltered areas, as found here and here. The wind has likely already started to redistribute this new snow into lee terrain.
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
- Closely monitor how the new snow is bonding to the old surface.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
Problems
Storm Slabs
With 30-50 cm of new snow, storm slabs are expected to remain reactive over the net few days. Deepest deposits are likely found where the wind has redistributed the new snow into lee terrain. 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: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 24th, 2021 4:00PM
