Avalanche Forecast
Issued: Jan 16th, 2025 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Parks Canada,
Avalanche Canada
Mt. Field, Mt. Stephen, and Mt. Dennis avalanche closure zones are CLOSED on Friday, January 17th.
New windslab development in the alpine down into treeline and possibly below with strong to extreme SW wind on Thursday.
Summary
Confidence
Moderate
Avalanche Summary
Thursday morning, several size 2 wind-triggered slabs and loose dry avalanches were observed in Little Yoho on Mt. Stephen and Mount Field. Avalanche control on Mt Bosworth produced one size 2.5 sliding on the deep persistent layer.
Snowpack Summary
10 cm new today with strong to extreme SW - W winds created new wind slabs at all elevations in terrain exposed to the wind. The upper pack may have a thin crust under the new snow on solar aspects and a surface hoar/facet interface under last week's snow, but no avalanches observed on this layer yet. The mid-pack is generally strong; however, a weak facet layer can be found near the ground in shallow snowpack areas. At treeline, average snowpack depth ranges from 120 to 150 cm.
Weather Summary
On Friday, we will see cooling temperatures (-14C) and easing winds as arctic air moves in for the weekend. Saturday temperatures will be in the -20C range with sunny skies and light NW wind
Terrain and Travel Advice
- Wind slabs are most reactive during their formation.
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Problems
Wind Slabs
Strong to extreme winds with light flurries created fresh reactive windslabs 10-30 cm thick in alpine lees. Winds were observed to be transporting snow below treeline. It's possible windslabs exist in isolated slopes that are open and exposed to wind below treeline.
Aspects: North, North East, East, South East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
The snowpack is generally deeper and, thus, stronger in the Little Yoho subregion than in most of the BYK forecast region. However, thin snowpack areas, such as windward and exposed terrain, will have weak basal facets at the base of the snowpack.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 17th, 2025 4:00PM
