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, Cornices and Wind Slabs.
shorton,
Avalanche Canada
Danger will elevate throughout the day as slopes warm up. Plan your day around avoiding sun-exposed slopes and cornices. Read more in this Forecasters' Blog.
Summary
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
A high pressure ridge brings clear skies and progressively warmer temperatures.
TUESDAY NIGHT: Clearing skies, light southwest wind, freezing level climbs from 1700 to 2000 m by the morning with treeline temperatures climbing to +2 C.
WEDNESDAY: Sunny, light southwest wind, freezing level climbs from 2000 to 2700 m throughout the day, treeline temperatures climb to +8 C.
THURSDAY: Sunny, light south wind, freezing level steady around 2800 m, treeline temperatures around +8 C.
FRIDAY: Mostly sunny, light south wind, freezing level steady around 2800 m, treeline temperatures around +8 C.
Avalanche Summary
Warm sunny weather this week will cause wet loose avalanches and cornice falls.
On Monday there were numerous wet loose avalanches on steep sun-exposed slopes (to size 2) as well as some natural wind slab avalanches in the alpine triggered by cornice falls. Over the weekend there were numerous size 1-2 human triggered storm and wind slab avalanches at treeline and alpine elevations around Shames and Kitimat (see photos in this MIN report).Â
Snowpack Summary
Sunny skies and rising freezing levels will result in melting surfaces everywhere except north-facing alpine terrain. In the alpine 20-30 cm of recent snow is quickly settling and strengthening, although wind slabs may linger on some steeper slopes. The mid/lower snowpack is strong and settled in most areas.Â
Cornices are large and looming along ridgelines, and are capable of triggering avalanches when they fail. Also, glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to minimize exposure to cornices and avoid slopes with glide cracks.
Terrain and Travel
- Avoid exposure to sunny slopes, especially in the afternoon.
- Avoid exposure to slopes that have cornices overhead.
- 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
Wet loose avalanches will start to run naturally on steep solar aspects when the sun comes out.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Strong solar radiation and warming will likely trigger the large cornices that hang over ridgelines. Cornice falls could trigger wind slab avalanches on the slopes below.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Lingering wind slabs formed by 20-30 cm of recent snow and wind may still be reactive on lee features on all aspects in the alpine.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 14th, 2021 4:00PM
