Cautious route finding & conservative decision making is essential.
Human triggered avalanches are expected, especially in areas where people haven't skied.
Remote and rider triggered persistent slabs avalanches are occurring daily.
Recent moderate south winds loaded lee features near ridgetop. Be careful as you transition into wind-affected terrain. Wind slabs may be most reactive on solar aspects where they sit on a crust.
A surface hoar layer, down 30-50cm, is reactive to human triggering. A second layer of large surface hoar is buried 50-80cm deep and sits on a crust. Use caution in terrain that has not seen recent rider traffic - this is where triggering is most likely.
This week field teams have remotely triggered numerous size 1 to 2 persistent slabs from low angle terrain at tree-line and below. These have been 40-60cm deep, failing on surface hoar layers in the upper snowpack.
In the Bostock drainage two separate size 2 avalanches were triggered from 10 to 40m away breaking small trees.
On Monday, a sz 2 avalanche in Cougar Creek East caught and injured a rider.
Up to 60cm of new snow fell this past week. Ridge-top winds created slabs in immediate lee features.
The Feb 9 surface hoar (SH) is buried at the bottom of this new snow (40-60cm down) and is reactive in tests.
Recent Spring-like temps and sunshine created several crusts in the upper snowpack, upon which the Feb 9 SH sits.
The Jan 26th layer, composed of surface hoar/facets/crust, is buried down 60-80cm. The largest surface hoar is preserved in sheltered areas below treeline.
The arctic airmass will slowly be pushed out with a warming trend towards Monday.
Tonight: Clear periods. Alp low -18°C. Light NW winds. Freezing level (FZL) valley bottom.
Fri: Sun and cloud. Alp high -13°C. Light SW winds. FZL valley bottom.
Sat: Sun and cloud. Alp high -9°C. Ridge winds S 20km/hr. FZL 1100m.
Sun: Mainly cloudy, isolated flurries. Alp high -5°C. S winds 20-35km/hr. FZL 1700m.
