Avalanche Forecast
Issued: Mar 21st, 2017 3:25PM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
High -
Weather Forecast
WENDESDAY: Flurries starting overnight with 3-8 cm of new snow, moderate south winds, alpine temperatures around -5 C. THURSDAY: Isolated flurries with trace accumulations, moderate southwest winds, alpine temperatures around -7 C.FRIDAY: Cloudy with scattered flurries, moderate south winds, alpine temperatures around -5 C.
Avalanche Summary
On Monday, a size 3 slab avalanche was triggered by a cornice fall on a north aspect at 1700 m north of Kispiox. Over the weekend, several reports describe reactive wind slabs above the March 14 crust, including a size 2.5 snowmobile-triggered avalanche in the Telkwas and a size 2 skier-triggered wind slab north of Kispiox. Additional MIN reports also describe recent natural activity in the size 2-3 range, one of which was triggered by a cornice fall.The recent activity should draw attention to the extent of recent wind transport as well as the March 14 crust's excellent performance as a sliding layer.
Snowpack Summary
Incoming winds and light flurries will transport snow in exposed terrain to form fresh wind slabs. Recent snow continues to settle, with amounts tapering with elevation. At lower elevations, the recent snow sits above a supportive rain crust (March 14). This crust has also been observed at higher elevations in the Telkwa area, and wind slabs have proven especially reactive where they sit above it. At higher elevations, wind has incrementally loaded a weak interface that was buried in late February. The interface is composed of facets, crusts, and surface hoar and may be 40-60 cm deep. There's still some uncertainty around the distribution and reactivity of this interface, but it has been reactive under skier traffic in the north of the region. Weak, sugary snow near the ground continues to be a concern in thin rocky areas.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 22nd, 2017 2:00PM