Avalanche Forecast
Issued: Jan 17th, 2020 1:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
ghelgeson,
Avalanche Canada
Wind slabs are widespread and may be found in areas you are not used to seeing them, seek out wind sheltered terrain this weekend to avoid wind slabs and find the best riding conditions. Steer clear of any glide cracks you come across, they've recently produced large avalanches.
Summary
Confidence
Low - Uncertainty is due to the extreme variability of wind effect on the snowpack. Uncertainty is due to the limited number of field observations.
Weather Forecast
Temperatures should begin to warm as southwest flow sets up this weekend, look for a few dribs and drabs of snow through the forecast period too.
FRIDAY NIGHT: Alpine temperature -18, light variable wind, no significant precipitation expected.
SATURDAY: Broken cloud cover, alpine temperature -8 C, light/moderate south wind, 5 to 10 cm of snow possible across the region.
SUNDAY: Broken cloud cover, alpine temperature -4 C, moderate south wind, 5 to 10 cm of snow possible across the region.
MONDAY: Broken cloud cover, alpine temperature -3 C, light/moderate south wind, trace of snow possible across the region.
Avalanche Summary
There have been a number of glide cracks that have failed naturally as very large avalanches in the Torpy area recently. Glide cracks are seemingly unpredictable and need to be given a wide berth. There are some great photos on the PGBCSki FB page.
A small wind slab was reported from west facing terrain at 2100 m Thursday. Wind slabs on west facing features are somewhat unusual but recent winds from a variety of directions have formed wind slabs in places we aren't used to seeing them.
On Tuesday, a natural size 2 persistent slab avalanche was observed on a south facing slope around 1750 m in the mountains near Crescent Spur, this avalanche is suspected to have failed on the late December Surface Hoar.
Snowpack Summary
20 to 50 cm of settled storm snow has been subject to winds from all directions. Wind slabs are likely to be found on all aspects at and above treeline.
A weak layer of feathery surface hoar buried in late December remains a concern. The layer has been found across much of the North Rockies region, but it has only become a problem in particular areas, such as around McBride and the McGregors/Torpy. It seems to be most prevalent in sheltered treeline features 50 to 150 cm below the surface.Â
Terrain and Travel
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Watch for areas of hard wind slab on alpine features.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
Problems
Wind Slabs
Recent winds from a variety of directions have formed wind slabs in places we aren't used to seeing them. Watch for wind slabs in all wind exposed terrain. Steep features near ridge crest are particularly suspect.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar may be found in parts of the region. There is uncertainty on where this layer is a problem, but it appears to be of highest concern in sheltered terrain features near treeline in the southern half of the region, particularly around McBride and the McGregors.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: Jan 20th, 2020 5:00PM
