Avalanche Forecast
Issued: Feb 27th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Forecast strong to extreme winds will have a continuous supply of snowfall to form new wind slabs across the region. Seek out sheltered snow at lower angles and avoid exposure to wind loaded overhead terrain.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
SATURDAY NIGHT: Cloudy with continuing flurries bringing about 5 more cm of new snow. Strong southwest winds.
SUNDAY: Cloudy with continuing flurries bringing 5-10 cm of new and 2-day snow totals to 10-20 cm, continuing but easing overnight. Strong to extreme southwest winds, easing a bit over the day and overnight. Alpine high temperatures around -9.
MONDAY: Cloudy with continuing flurries bringing about another 5 cm of new snow and 3-day totals to 15-25 cm, continuing again overnight. Strong to extreme southwest winds. Alpine high temperatures around -11.
TUESDAY: Cloudy with another round of flurries with another 5-10 cm of new snow and 4-day totals of 25-40 cm. Moderate to strong southwest winds. Alpine high temperatures around -12.
Avalanche Summary
Evidence of a recent storm slab avalanche cycle to size 2 has been observed in the days since last weekend's storm. Heightened avalanche danger has been maintained through the week by subsequent bouts of elevated southwest and northwest wind.
Looking forward, older wind slab formations will take a back seat to the active development of touchy new slabs over the coming days as new snow and strong to extreme winds reshape the upper snowpack.
Snowpack Summary
Strong southwest winds have been redistributing light new snow amounts as well as older storm snow still able to be picked up by the wind and forming new wind slabs in leeward terrain while stripping windward slopes. Northwest winds have also played a significant role in the recent wind history.
Below the surface, 60+ cm of snow from last weekend's storm rests on yet more wind affected snow in exposed terrain and possibly a weak layer of surface hoar in sheltered areas, as reported here and here.Â
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 newly formed and reactive wind slabs as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.
Problems
Wind Slabs
Expect to find older wind slabs on a wide range of aspects and touchy new slabs to the lee of the wind if you're nearing exposed terrain. A steady supply of new snow and even stronger wind should keep this problem active for several days.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 1st, 2021 4:00PM
