Natural avalanches are likely and human triggered avalanches are very likely.
Use conservative route selection. Choose simple, low angle terrain with no overhead hazard.
Two persistent weak layers are buried down ~90 and ~120 cm. New snow combined with extreme winds could overload these weak layers triggering large, destructive avalanches. These weak layers are also still reactive to human triggering.
30-60 cm of storm snow will be redistributed by extreme Westerly winds. Touchy storm slabs will form rapidly in all exposed terrain. Natural avalanches are likely. Storm slabs in motion may step down to deeper layers resulting in large avalanches.
On Thursday, natural avalanches will be likely and human triggered avalanches will be very likely. Avalanches triggered in the storm snow could step down to persistent weak layers. Large avalanches, bigger than size 3, are expected.
On Wednesday, field teams triggered small avalanches on a steep north aspects below treeline.
On Tuesday, riders were triggering size 1 avalanches down 80 cm on a persistent weak layer MINs and seeing signs of instability MIN.
Storm slabs will build rapidly on Thursday with forecasted extreme winds and snowfall.
The incoming storm will further bury persistent weak layers and load them rapidly.
The Feb 9 surface hoar (SH) is down 80-110 cm and remains reactive in snowpack testing. The Feb 9 SH sits over a crust on solar aspects.
The Jan 26th layer, composed of surface hoar/facets/crust, is buried down 120-140 cm. The largest surface hoar is preserved in sheltered areas below treeline.
An intense storm starting Wednesday night and continuing to Friday is expected to bring ~40-60 cm of snow with extreme westerly winds.
Tonight Flurries, 10-15 cm. Alp low -9°C. Winds SW 55-70 km/h. Freezing level (FZL) 800m.
Thurs Snow 20-30 cm. High -8°C. Winds W 55, gusting to 90 km/h. FZL 900m.
Fri Flurries 5-10 cm. High -6°C. Winds W 25, gusting to 50 km/h. FZL 900m.
Sat Cloud/Sun High -8°C. Winds Light. FZL 1100m.
