Avalanche Forecast

Issued: Jan 23rd, 2019 4:31PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs.

kdevine, Avalanche Canada

Kootenay Boundary.

A weak layer of surface hoar (feathery crystals) exists down 30-50 cm. This layer is most pronounced at treeline and below. Keep it in mind in areas such as cutblocks and open glades where layers like this could catch people by surprise.

Summary

Confidence

Moderate -

Weather Forecast

WEDNESDAY NIGHT -Mainly cloudy with clear periods / northwest winds, 20-40 km/h / alpine low temperature near -8THURSDAY - Cloudy with sunny periods / northwest winds, 20-40 km/h / alpine high temperature near -5 / possible alpine temperature inversionFRIDAY - Mainly cloudy with sunny periods / northwest winds, 30-50 km/h / alpine high temperature near -3 / freezing level 1100 m SATURDAY - Cloudy with sunny periods / northwest winds, 20-40 km/h / alpine high temperature near 0 / freezing level 2000 m / possible alpine temperature inversion

Avalanche Summary

Several explosives triggered storm slab avalanches to size 2 were reported on northerly aspects on Wednesday.No new avalanches were reported in the region on TuesdayOf note, a remotely triggered (triggered from a distance) size 2.5 avalanche was reported on Saturday on a southeast aspect at 2150 m. The avalanche occurred in a terrain feature where the snowpack varied in depth from deep to shallow.

Snowpack Summary

30-50 cm of recent snow has fallen in the region. This snow sits on surface hoar (feathery crystals) in shaded areas that are sheltered from the wind, thin rain crusts in some areas, and sun crusts on south facing slopes. The surface hoar is most prominent at treeline and below. Recent snowpack tests suggest that the snow may be poorly bonded to these layers in some areas. Another prominent weak layer in the snowpack is a layer that formed in early December and is buried approximately 70-110 cm. This layer consists of a rain crust, surface hoar, and facets (sugary snow). There have been no recent reports of avalanches on this layer, however a large load, such as a cornice fall may still have the potential to trigger large avalanches on this layer.

Problems

Persistent Slabs

30-50 cm of recent storm snow sits on a weak layer of surface hoar (feathery crystals), thin rain crusts and sun crust on south facing slopes. The surface hoar is most prominent at lower elevations.

Watch for whumpfing, hollow sounds, and shooting cracks.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution in steep terrain at treeline and below such as cut banks, cut blocks and open glades.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 24th, 2019 2:00PM