Use caution as you transition into wind exposed terrain, new snow combined with strong winds have promoted wind slab development at upper elevations.
30 to 50 cm of total recent storm snow and strong west winds have formed wind slabs in many areas. Wind slabs will be most reactive in lee terrain features.
WEDNESDAY NIGHT- Clear with cloudy periods / northwest wind, 20-30 km/h / alpine low temperature near -11
THURSDAY- A mix of sun and cloud / northwest wind, 20-30 km/h / alpine high temperature near -10
FRIDAY- Mainly cloudy with flurries, 5-10 cm / northeast wind, 20-40 km/h / alpine high temperature near -12
SATURDAY- Mainly cloudy with flurries, 5 cm / northeast wind, 30-50 km/h / alpine high temperature near -22
Wind slabs at upper elevations may be reactive to human triggers. Cornices have also grown large with the recent weather pattern, and a cornice failure could trigger a wind slab avalanche on the slope below.
On Tuesday, there were a few reports of cornice triggered wind slab avalanches up to size 1.5.
On Monday, there were several natural, human and explosives triggered storm slab avalanches up to size 2. These were mostly on north through east aspects around 2000 m.
On Sunday, loose dry and soft slab avalanches were sensitive to human triggering and explosives avalanche control work to size 1.5. Avalanches have been 10 to 20 cm in depth, running fast and far.
10-15 cm of fresh snow from Tuesday night with ongoing strong winds will continue to promote wind slab development.
A total of 30 to 50 cm of recent storm snow sits on buried wind slabs in exposed areas and a sun crust on solar aspects (south through west facing slopes). Melt-freeze crusts extend up to 1900 m on other aspects.
A thick crust that has facets associated with it sits 30-60 cm below the surface. There has been only one avalanche reported on this layer since February 17th. The middle of the snowpack is generally strong, but the base of the snowpack contains weak basal facets that are most prominent in shallow rocky start zones.
