Avalanche Forecast
Issued: Dec 13th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
rbuhler,
Avalanche Canada
Wind slabs continue to be the primary concern on Tuesday. Due to recently shifting wind directions, slabs should be expected on all aspects in exposed terrain.
Summary
Confidence
Weather Forecast
An Arctic high pressure system is expected to be the dominant feature for most of the week bringing cold and dry conditions to the region.
Monday Overnight: Mostly clear skies, light to moderate NE-E winds, treeline temperature around -20 °C.
Tuesday: Mostly sunny, light to moderate variable winds, treeline high around -20 °C.
Wednesday: A mix of sun and cloud, light to moderate variable winds, treeline high around -18 °C.
Thursday: A mix of sun and cloud, moderate to strong NW winds, treeline high around -16 °C.
Avalanche Summary
On Sunday, the only reported avalanches were explosive triggered wind slabs up to size 1.5 in the far south of the region. On Saturday, natural size 2-3 slab avalanches were reported in the far SW corner of the region which were typically 30-50 cm thick and occurring on NW aspects. A natural cornice release on Saturday also triggered a size 2.5 wind slab on a SE aspect in the alpine. This MIN from the Hankin on Saturday has some great photos of natural avalanche activity above the cabin.
On Tuesday, wind slabs are expected to remain the primary concern in the region. Newer wind slabs which formed on Monday from the NE winds are expected to be most reactive but the older wind slabs from the weekend storm are still expected to be reactive, especially in steep, unsupported terrain features.
Snowpack Summary
Over the weekend, the region typically saw 10-20 cm of new snow. This new snow was accompanied by strong SW winds have formed reactive wind slabs in exposed terrain. On Monday, strong outflow (NE-E) winds are expected to form new wind slabs on the opposite aspects from the weekend storm and wind slabs should be expected on all aspects.
An early season crust can be found near the base of the snowpack. This layer was reactive to heavy triggers such as cornices and explosives last week but now appears to have stabilized and gone dormant.
Snowpack depth at treeline typically ranges from 150-200 cm, with higher values in the western part of the region and tapering to the east.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Be alert to conditions that change with elevation and wind exposure.
Problems
Wind Slabs
Wind slabs are expected to be most reactive on south and west aspects as a result of the strong NE winds on Monday. However, north and east aspects also likely still have some reactive wind slabs from the storm on the weekend. As a result, wind slabs should be expected on all aspects in exposed terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 14th, 2021 4:00PM
