Recently formed wind slabs may remain reactive to human triggers; especially where they are sitting on a slippery sun crust.
Cornices are very large in many areas, minimize your exposure time below them.
Recently formed wind slabs may remain active to human triggers in isolated locations; especially where they are sitting on a slippery sun crust.
Cornices are very large in many areas, be aware of what's above your head.
TUESDAY NIGHT: Clear / Light northeast winds / Low of -24 / Freezing level surface.
WEDNESDAY: Sunny / Light north wind / High of -10 / Freezing level surface.
THURSDAY: Increasing cloudiness / Moderate northwest wind / High of -8 / Freezing level surface.
FRIDAY: Cloudy / Moderate northwest wind / High of -4 / Freezing level rising to 1100 m.
A naturally triggered cornice failure and a skier triggered size 1.5 wind slab on a southeast aspect were reported on Monday.
Recent west and northwest winds have formed wind slabs on lee features at treeline and above. These slabs may remain more reactive on south facing slopes where they are sitting on a slippery sun crust. Below the recent snow, there may be a layer of small surface hoar that is likely most pronounced on northerly aspects or sheltered locations.
Lower elevations have seen warm temperatures last week and have a melt freeze crust on the surface below 1600 m.
The late February weak layer combination of crust, facets and surface hoar is down 30-40cm deep, and has been reactive mostly on south facing slopes during periods of sun.
Two persistent weak layers from mid February and late January are buried 50-120cm deep. No recent avalanches have been reported on these layers but they continue to produce the occasional notable result in snowpack tests.
The most likely triggers of these persistent weak layers are strong solar radiation and/or large triggers such as smaller avalanches in motion, cornices, or snowmobiles.
