Avalanche Forecast
Issued: Mar 8th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Cornices.
mconlan,
Avalanche Canada
Buried weak layers remain possible to be triggered, where they exist. Cornices and sun-exposed slopes will deteriorate during the heat of the day, potentially increasing the likelihood of avalanche activity.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
MONDAY NIGHT: Clear skies, 10 km/h northeast wind, alpine temperature -6 C.
TUESDAY: Morning clear skies and afternoon clouds, 20 km/h southwest wind, alpine temperature -6 C, freezing level rising to 1500 m.
WEDNESDAY: Morning clear skies and afternoon clouds, 20 km/h southwest wind, alpine temperature -6 C.
THURSDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 20 km/h southwest wind, alpine temperature -6 C.
Avalanche Summary
No avalanches were observed on the weekend or Monday, besides some small loose avalanche out of steep terrain. The most recent persistent slab avalanche activity was on Friday, being triggered by explosives.
Snowpack Summary
A few centimetres of snow overlies a melt-freeze crust in many areas, with the exception being on north aspects above around 1700 m. Wind slabs may still exist on northerly aspects at alpine and treeline elevations. On solar aspects and below the freezing level, the snow may moisten during the heat of the day.
Up to 50 cm of snow sits above a variety of old interfaces that formed in mid-February. There is 60 to 100 cm sitting on a persistent weak layer that was buried in late January. These interfaces are mostly made up of sugary faceted grains, hard wind pressed snow, feathery surface hoar in wind-sheltered locations, and a melt-freeze crust on steep solar aspects. Periodic avalanches continue to be triggered on these layers. Check out this MIN for photos of the positioning of the layers in the snowpack.
Terrain and Travel
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Persistent Slabs
Two persistent weak layers may be found in the snowpack:
- The upper layer is buried 30 to 50 cm and primarily consists of sugary faceted grains.
- The deeper layer is buried 60 to 100 cm. This layer consists of surface hoar, faceted grains, and/or a hard melt-freeze crust. The problem has been most prevalent around treeline and in openings below treeline, but also reaches into the lower alpine.
These layers could be triggered by riders anywhere they still exist. A mild, sunny Tuesday may increase the likelihood of triggering these layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices will weaken with sunny skies and relatively mild air temperature. The snow on sun-exposed slopes may also moisten, so use caution during the heat of the day.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 9th, 2021 4:00PM
