Avalanche Forecast
Issued: Dec 14th, 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 main concern on Wednesday. Due to recently shifting wind directions, slabs should be expected on all aspects in exposed terrain.
Summary
Confidence
High - Confidence is due to a stable weather pattern with little change expected.
Weather Forecast
The Arctic high pressure system to the north continues to be the main weather influencer except for Wednesday overnight and early Thursday when a weak trough crosses the south of the province bringing light snowfall to the region.Â
Tuesday Overnight: Partly cloudy, light to moderate SW winds, treeline temperature around -15 °C.
Wednesday: A mix of sun and cloud, light to moderate SW winds, treeline high around -12 °C.Â
Thursday: Cloudy with light snowfall in the morning, clearing in the afternoon, moderate to strong NW winds, treeline high around -12 °C.
Friday: A mix of sun and cloud, light to moderate variable winds, treeline high around -14 °C.Â
Avalanche Summary
On Monday, three natural storm slab avalanches up to size 2.5 were reported on N-NE aspects south of Valemount although these may have occurred on Sunday. On Sunday, a natural size 2 storm slab was reported near Valemount on a south aspect in the alpine and a natural cornice triggered storm slab was reported near Blue River on a northeast aspect which was 40-50 cm thick.Â
On Wednesday, wind slabs are expected to remain the primary concern in the region. The wind is expected to have shifted direction on Monday night so watch for wind slabs on all aspects.Â
Snowpack Summary
The region typically saw 15-25 cm of new snow over the weekend with strong SW winds which formed reactive wind slabs in exposed terrain. Another 15-25 cm of new snow accumulated on Monday and Tuesday while the wind shifted to a NE direction so new wind slabs have likely formed on the opposite aspect to the slabs from the weekend.Â
Two interfaces from early December may be found down around 60-100 cm. The December 7 interface consists of a thin crust and/or surface hoar while the December 1 interface consists of a thick crust with facets. These layers appear to have stabilized through most of the region but may be still reactive in isolated areas.Â
The lower snowpack is now generally well settled and stable although an old, faceted crust is likely found near the base of the snowpack.Â
Terrain and Travel
- Be careful 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
Old wind slabs may be lingering on north and east aspects from the weekend storm. The wind recently shifted to a NE direction and new wind slab formation is expected, primarily on south and west aspects. 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 15th, 2021 4:00PM
