Avalanche Forecast
Issued: Jan 22nd, 2020 2:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
MBender,
Avalanche Canada
New snow falling with wind and warm temperatures will continue to promote wind slab formation in exposed terrain over the next few days.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
WEDNESDAY NIGHT: Cloudy with clear periods, moderate wind from the southwest, alpine high temperatures around -4 C.
THURSDAY: Flurries, accumulation 5-15 cm, moderate wind from the southwest, freezing level up to 1500 m and alpine high temperatures around -2 C.
FRIDAY: Scattered flurries, moderate to strong wind from the southwest, freezing level up to 1600 m and alpine high temperatures around -2 C.
SATURDAY: Mainly cloudy, moderate to strong wind from the southwest, freezing level up to 1500 m and alpine high temperatures around -3 C.
Avalanche Summary
On Monday there were reports of numerous natural wind slab and cornice triggered avalanches running to size 2 in the alpine on a variety of aspects. See this MIN post for more details.
There have also been a number of glide cracks that 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. Mild temperatures this week could increase the sensitivity of persistent and glide slabs.
Snowpack Summary
Recent snow has settled with warm temperatures and been blown around by wind from various directions, resulting in wind slabs on all aspects at and above treeline. A weak layer of 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.
Terrain and Travel
- Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
- Be careful as you transition into wind affected terrain.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Problems
Wind Slabs
Recent wind from a variety of directions has formed wind slabs in places we aren't used to seeing them. Watch for wind slabs in all wind exposed terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A weak layer of buried 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 23rd, 2020 5:00PM
