Avalanche Forecast
Issued: Mar 20th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet and Persistent Slabs.
ahanna,
Avalanche Canada
With increasing cloud cover and slightly cooler temperatures, the potential for solar induced avalanche activity will decrease through the day Saturday. Still watch for signs of instability such as pinwheeling on sun-exposed slopes when the sun feels strong.
Summary
Confidence
Weather Forecast
Friday night: Clear. Moderate to strong northwest wind. Freezing level 500 m.
Saturday: Increasing cloud. Strong northwest wind. Freezing level 1100 m.
Sunday: 10-20 cm new snow. Wind easing to light, variable. Freezing level 900 m.
Monday: Mix of sun and cloud. Light northeast wind. Freezing level 1200 m.
Avalanche Summary
Natural loose wet avalanche activity has been observed on sun-exposed slopes during the heat of the day over the last few warm days. A few cornices were also triggered by the warming. Some glide slab activity has been reported recently out of steep terrain where snow sits over smooth surfaces.
If you decide to travel in the backcountry, consider sharing your observations with us and fellow recreationists via the Mountain Information Network (MIN) to supplement our data stream as operators are shutting down. Even just a photo of what the day looked like would be helpful.
Snowpack Summary
Wind-affected snow surfaces exist in exposed terrain at alpine and treeline elevations from predominantly northeast wind. Previously formed wind slabs have likely bonded given the recent warm temperatures. In sheltered terrain, soft and faceted snow may be found. Clear skies have melted the snow surface on sun-exposed slopes during the day and frozen it into a melt-freeze crust during nights.
A layer of surface hoar crystals is buried around 30 to 60 cm in sheltered areas at and below treeline. See this MIN from the Shames area that shows this layer when it was on the surface, prior to burial on March 9.
An early-season layer of faceted grains and a melt-freeze crust may linger at the base of the snowpack. A large load, such as a cornice fall, has the potential of triggering it.
Terrain and Travel
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- Be aware of the potential for large avalanches due to the presence of buried surface hoar.
- Carefully evaluate steep lines for wind slabs.
Problems
Loose Wet
Loose wet avalanche activity is most likely during the heat of the day when clear skies prevail. Avoid overhead exposure on sun-exposed slopes as the snowpack heats up. Note that cornices are also large and could release during daytime heating.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar crystals is buried around 30 to 60 cm and has been reactive to both human and natural triggers. This weak layer is most problematic in sheltered terrain at treeline elevations, where the surface hoar remains preserved.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 21st, 2020 5:00PM
