Avalanche Forecast
Issued: Apr 13th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Wind Slabs and Cornices.
shorton,
Avalanche Canada
Danger will progressively increase as the days get warmer and sunnier. Read more in this Forecasters' Blog.
Summary
Confidence
Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
TUESDAY NIGHT: Clear skies, 40 km/h northeast wind, freezing level drops to valley bottom with treeline temperatures dropping to -7 C.
WEDNESDAY: Mix of sun and cloud, 40 km/h northeast wind, freezing level to 2000 m with treeline temperatures around -1 C.
THURSDAY: Sunny with a few clouds, light northeast wind, freezing level climbing to 2300 m with treeline temperatures reaching +1 C.
FRIDAY: Sunny, light northeast wind, freezing level climbing to 2500 m with treeline temperatures reaching +4 C.
Avalanche Summary
Recent reports are limited to a few small dry loose and wet loose avalanches on Sunday and Monday. Warm sunny weather this week will increase the size and likelihood of wet loose avalanches and cornice falls.  Â
Prolonged warming may increase the sensitivity of deeply buried layers later this week, although there is a fair bit of uncertainty about how likely this is in the South Rockies region. There have been some notable slab avalanches reported to the north of the region over the last few days including a skier triggered avalanche in Kananaskis Country on Saturday (see reports here and here) as well as a natural deep slab avalanche in Kootenay National Park on Tuesday (see photo here). These avalanches provide a good reminder of why it's good to be extra cautious during the heat of the day this time of year.
Snowpack Summary
North alpine terrain has roughly 30 cm of settling powder with wind slabs possible on steep exposed slopes. Other terrain is undergoing a melt-freeze cycle with successive days of warm sunny weather. The lower snowpack is generally strong and settled, however weak snow at the base of the snowpack may become a concern later this week when things really warm up. The snow line is creeping up to higher elevations, so some common access points are now snow free.
Terrain and Travel
- Avoid exposure to sunny slopes, especially in the afternoon.
- Cornices become weak with daytime heating.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
Problems
Loose Wet
Expect small wet loose avalanches to occur naturally on solar aspects when the sun comes out.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Watch for pockets of unstable snow in steep alpine terrain.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Cornices
Strong solar radiation and warming may trigger the large cornices that hang over ridgelines.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 14th, 2021 4:00PM
