Avalanche Forecast
Issued: Mar 21st, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Wind Slabs and Loose Wet.
mconlan,
Avalanche Canada
A warming trend has the potential of increasing avalanche danger. Head out with a conservative mindset and dial back your terrain choices until the weather cools.
Summary
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
MONDAY NIGHT: Mostly cloudy with no precipitation, 20 km/h southwest wind, alpine temperature -4 C, freezing level 1500 m.
TUESDAY: Mostly cloudy with early-morning snowfall, accumulation 1 to 3 cm, 40 to 60 km/h southwest wind, alpine temperature -1 C, freezing level rising to 2000 m.
WEDNESDAY: Cloudy with snowfall, accumulation 10 to 20 cm snow above the rain-snow line, 20 to 40 km/h southwest wind, alpine temperature -2 C, freezing level 2000 m dropping to 1500 m.
THURSDAY: Clear skies with no precipitation, 10 km/h southwest wind, alpine temperature -7 C.
Avalanche Summary
A few more persistent slab avalanches were triggered on the weak layer described in the Snowpack Summary near Blue River. The avalanches were large (size 2 to 3) and occurred on east and northwest aspects around treeline. This layer should be treated as suspect anywhere it exists.
Looking forward, avalanche activity may pick up on Tuesday into Wednesday with a rise in the freezing level. There's uncertainty in exactly what the warming will do to the snowpack, so adopting a conservative mindset will be important.
Snowpack Summary
A bit of snow and strong wind are forecast for Tuesday along with warm air. New wind slabs may form at high elevations. A spring, moist snowpack exists below around 1500 m. There's uncertainty in what the warming will do, but it has the potential of destabilizing the snowpack and triggering avalanches.
A weak layer may be found around 40 to 60 cm deep, which has been most prominent in the south of the region (e.g., access points between Clearwater and Valemount). The layer consists of surface hoar crystals in treeline terrain in areas sheltered from the wind and otherwise a hard melt-freeze crust associated with weak faceted grains on sun-exposed slopes (i.e., east, south, west). This layer continues to form large avalanches in the south of the region. Check out this blog for more information.
The remainder of the snowpack is well-bonded.
Terrain and Travel
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Persistent Slabs
A weak layer may be found around 40 to 60 cm deep. The layer consists of weak faceted grains above a hard melt-freeze crust on sun-exposed slopes and surface hoar in shaded areas sheltered from the wind. This layer has been most problematic in the southern portion of the region (e.g., Wells Gray, Blue River, Valemount).
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slabs may be found at high elevations. Use caution in steep, lee terrain features.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
A warming trend may trigger wet loose avalanches out of steep terrain. Activity is most likely when dry snow is being wetted by rain or if the sun pokes through the clouds.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 22nd, 2022 4:00PM
