Avalanche Forecast
Issued: Mar 18th, 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.
mconlan,
Avalanche Canada
Loose wet avalanche activity on sun-exposed slopes and cornice falls are expected to continue during the heat of the day. Use caution around sheltered treeline where persistent slabs could be triggered.
Summary
Confidence
High - Confidence is due to a stable weather pattern with little change expected.
Weather Forecast
WEDNESDAY NIGHT: Partly cloudy, light south wind, alpine temperature -1 C, freezing level 1200 m.
THURSDAY: Clear skies, light east wind, apine temperature -1 C, freezing level 1200 m.
FRIDAY: Clear skies, light northwest wind, alpine temperature 0 C, freezing level 1400 m.
SATURDAY: Mix of sun and cloud, moderate to strong northwest wind, alpine temperature -5 C, freezing level 1000 m.
Avalanche Summary
There was evidence of natural loose wet avalanche activity on sun-exposed slopes on Tuesday. A few cornices were also triggered by the warming. This trend is expected to continue with generally sunny skies and relatively warm air temperature.
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 surface exist in exposed terrain at alpine and treeline elevations from predominantly northeast wind. Previously formed wind slabs have likely bonded given the recent warming trend. 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 steep slopes when air temperatures are warm, or solar radiation is strong.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
- 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 19th, 2020 5:00PM
