Avalanche Forecast
Issued: Feb 10th, 2020 5:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
ghelgeson,
Avalanche Canada
We're seeing a lot of very large destructive avalanches releasing naturally and being triggered by humans, these can only be managed by avoiding travel on the bigger more complex terrain features. Wind slabs remain an active problem, especially near ridge crest.
Summary
Confidence
Weather Forecast
The forecast period is marked by high winds accompanied by dribs & drabs of precipitation.
MONDAY NIGHT: Freezing level around 1200 m, strong to extreme southwest wind, 2 to 10 cm of snow expected.
TUESDAY: A few clouds, freezing level around 600 m, but it could extend as high as 1200 m, strong northwest wind, no significant snowfall expected.
WEDNESDAY: Broken cloud cover, freezing level at valley bottom, moderate to strong southwest wind, trace of snow possible during the day, 2 to 8 cm possible Wednesday Night.
THURSDAY: Overcast, freezing level around 700 m, moderate to strong southwest wind, trace of snow possible.
Avalanche Summary
Since February 3rd there have been many very large destructive avalanches failing deeply on buried surface hoar and crust/facets at the bottom of the snowpack. The bulk of the activity is above treeline on north through east facing aspects, but all alpine slopes that have not yet avalanched need to be treated as suspect. A few examples of the most recent activity are reported here:
Feb 9: Very large avalanche on the Kathlyn Face near Smithers. Details/Photos here and here.
Feb 9: Large avalanche in the French Peak Complex. Details/Photos here.
Feb 9: Very large avalanche near the Pine Creek Trail. Details/Photos here.
Feb 8: Large snowmobile triggered avalanche in the Babines. Details/Photos here.
Feb 8: Very large avalanche on Mt. Elmstead above Silver King Basin Trail in the Babines. Details/Photos here.
Persistent slabs are not the only problem either, over the weekend some touchy wind slabs were observed, check out the details here.
Snowpack Summary
Open terrain continues to be heavily affected by strong wind from the west which has been actively loading lee terrain features and seems to be pushing the persistent slab problem to it's breaking point. Crusts can be found on the surface up to roughly 1200 m and on open south-facing slopes. Weak layers formed during cold weather in January have reactivated and have consistently been producing very large avalanches since February 3rd.
Depending on location these layers may be composed of soft facets or surface hoar and are typically are buried 60-120 cm below the surface. Crust/facet layers also lurk at the base of the snowpack, especially in shallower (eastern) areas.
The most recent signs of instability with these deeper layers have been around Smithers, Hazelton, the Kispiox and the Babines, but persistent weak layers could be a problem on slopes anywhere in the region.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
- Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.
- Avoid lingering or regrouping in runout zones.
Problems
Wind Slabs
Watch for the formation of fresh wind slabs as strong wind generally out of the west/southwest and northwest continue Tuesday.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Many very large, deep and destructive avalanches have been human triggered and have ran naturally since February 3rd. As visibility improves and the days grow longer there is a natural tendency to push into new terrain, but we need to recognize that places that haven't seen a lot of traffic may actually be more likely to produce these monster avalanches than places with lots of tracks. Regardless, any alpine feature that has not yet slid needs to be treated as suspect. The frequency of these avalanches seems to be picking up and this problem isn't expected to go away anytime soon.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 11th, 2020 5:00PM
