Avalanche Forecast
Issued: Feb 15th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Wind Slabs and Deep Persistent Slabs.
jminifie,
Avalanche Canada
The best way to manage a complex snowpack like the one in this region is to stick to smaller, low consequence terrain. Don't let your guard down as large persistent and deep persistent slab avalanches are still being reported every two or three days.
Summary
Confidence
Avalanche Summary
A veritable smorgasbord of natural and explosives triggered in addition to skier controlled avalanches continue to be reported from the region. From smaller wind slab avalanches to large persistent slab avalanches and even a few cornice failures. This speaks to the complexity of the snowpack in this region and the potential for an avalanche on any given day.
This MIN from Grizzly Bowl west of Golden illustrates the potential for cornice failures and their ability to trigger larger slabs.
Snowpack Summary
15-40 cm of of recent storm snow has been variably distributed by winds and is settling above a layer of surface hoar, facets, and/or crust. This layer has become reactive in the southern and western parts of the Purcells, where it is more deeply buried. A new sun crust could be present on steep south aspects at treeline and below.
The lower snowpack contains a widespread layer of large, weak facets that is typically 80 to 150 cm deep. Snowpack depths at treeline range between 80 and 200 cm, with the shallowest depths found on the eastern edge of the Purcells.
Weather Summary
Wednesday night
Mostly clear. Winds from the west and southwest 20 km/h. Temperature -15˚C in the alpine.
Thursday
Starting clear with clouds increasing into the afternoon. Flurries beginning late in the day bringing 5 cm of new snow. Wind 15 km/h from the southwest. Temperature -10˚C.
FridayA mix of sun and clouds. Flurries delivering 5 cm of new snow. Wind 10 km/h from the west. Temperature -8˚C.
SaturdayCloudy. 5-10 cm of new snow. Wind 10km/h from the west. Temperature -9˚C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use careful route-finding and stick to moderate slope angles with low consequences.
- Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
- Avoid steep convex slopes.
- Be especially cautious as you transition into wind affected terrain.
Problems
Persistent Slabs
Large avalanches have been triggered on a 40 to 80 cm deep layer of surface hoar and facets that was buried in late January. This problem seems most concerning in the western and southern Purcells, where the layer is more deeply buried and primed for human triggering. Steep open slopes should be avoided.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slab avalanches are possible to trigger in lee terrain after recent snow has been redistributed by southwest wind. The bond of this snow to underlying layers is suspect.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
It remains possible for riders to trigger a weak layer of facets near the base of the snowpack. The most likely area to trigger it is in shallow areas with variable snow depths. Avoid thin and rocky start zones and select routes that avoid travelling through or under large avalanche paths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 16th, 2023 4:00PM
