Another 10-15cm of snow in the forecast steadily loads up two persistent weak layers in the upper snowpack.
The lure of untouched powder is powerful, but these weak layers are being stressed by human passage and releasing in larger and larger slabs.
The possibility of human triggering is real, especially in zones less travelled.
Recent moderate south winds loaded lee features near ridgetop. Be careful as you transition into wind-affected terrain. Wind slabs may be most reactive in areas where they sit over a crust on slopes than receive a lot of sunshine (south and west facing).
A layer of surface hoar (up to 40mm below treeline) is buried 50-80cm deep and sits on a crust.
Use caution in terrain that has not seen recent rider traffic and areas that are "off the beaten path" - this is where triggering is most likely.
Today, a field team remote triggered a sz 2 slab, 60-70cm deep, into Bostock Creek from 10m away. The debris snapped a couple small trees near its toe.
Several MIN reports from yesterday (Perley Rock, Ross Pillows, Cheops N Bowl, etc) spoke of natural and human triggered slabs in the upper 40-80cm of the snowpack, with a couple folks caught but uninjured in the debris.
On Saturday the Frequent flyer path ran sz 2.5 into the creek, stepping down to the Jan 26th layer on the fan.
50-60cm of snow fell the past week and was redistributed by gusty winds in the Alpine and Treeline.
Recent Spring-like temps and sunshine have formed several crusts in the upper snowpack, along with a sneaky Feb 9 surface hoar layer down 30-40cm.
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.
Below this the snowpack is well settled/strong.
Flurries followed by dropping temps later in the week.
Tonight: Flurries, 5cm. Alp low -8°C. Winds SE 15-30km/h. Freezing level (FZL) 800m.
Tue: Flurries, 5cm. Alp High -7°C. Wind NW 10-25km/h. FZL 1000m.
Wed: Sun & cloud, isolated flurries. High -12 °C. Winds W 15km/h. FZL 500m.
Thurs: Cloudy, isolated flurries. High -12°C. Winds Light winds. FZL 600m.
