The January 26th Surface Hoar layer woke up last week, producing very large avalanches throughout Rogers Pass.
Slopes that have not yet failed will be ripe for human triggering and should be absolutely avoided!
With continued loading the next few days, manage exposure to overhead avalanche terrain with extra caution.
Two persistent weak layers are buried down ~100 and ~130 cm. Last weeks snow, combined with extreme winds, overloaded these layers triggering large, destructive avalanches. Be very suspect of slopes that haven't recently avalanched. These weak layers are still within human triggering depths.
Up to 30 cm of new snow accompanied by warm temps and light-moderate Southerly winds has created fresh storm slabs in open terrain.
We saw 3 fresh size 1 natural avalanches on a treeline East aspect on Wednesday, ~100cm deep, on the Jan 26th layer.
Explosive tests at Fidelity Tues. produced a size 3 avalanche on the Jan 26 surface hoar, which remoted a second size 3 slab 50m away.
Last Friday's cycle saw natural and explosive triggered avalanches up to size 4, running to valley bottom. The carnage of downed timber and debris littering Connaught and Asulkan is sobering.
See the following link to a recent MCR.
15-20cm of new snow covers thick wind slabs on leeward features (from previous Extreme S'ly winds), and a suncrust on solar aspects (SE through W).
The Feb 9 surface hoar (SH) is down 90-120 cm and remains reactive in snowpack testing. The Feb 9 SH sits over a crust on solar aspects.
The Jan 26th layer is buried down 130-160 cm, and is composed of very large surface hoar (up to 40mm), facets, and/or a crust, The largest surface hoar is preserved in sheltered areas below treeline.
Snow flurries continue Friday, followed by an organized system bringing snowfall Saturday and Sunday.
Tonight Isolated Flurries. Alpine Low -7°C. Freezing level (FZL) 1100m. Gusty West ridgetop wind.
Fri Scattered flurries (5cm). High -4 °C. FZL 1600m. Light SW wind.
Sat Snow (15-20cm). Low -5 °C, High 0 °C. FZL 2000m. Strong gusty SW wind.
Sun Snow (5-10cm). Low -15 °C, High -4 °C. FZL 1500m. Strong gusty SW wind.
