Avalanche Forecast
Issued: Apr 8th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
swerner,
Avalanche Canada
New snow and strong wind are driving the avalanche hazard. Reactive wind slabs will likely be found at treeline and in the alpine.
Loose snow avalanches can be expected in the new snow on steep terrain features. They can run far and fast, especially where they sit on a crust.
Summary
Confidence
Weather Forecast
Unsettled weather continues with more snow, strong winds, and seasonally cool temperatures.
Friday: Cloudy with light snow 5-10 cm. Ridgetop wind moderate to strong from the southwest. Alpine temperatures near -12 and freezing levels 1100 m.
Friday Night: Snow amounts 5-10 cm with strong southwest winds at ridgetop.
Saturday: A mix of sun and cloud with convective flurries. Ridgetop wind light from the northwest. Alpine temperatures near -13 and freezing levels 800 m.
Sunday: A mix of sun and cloud with light ridgetop wind from the northwest. Alpine temperatures -10 and freezing levels 1300 m.
Avalanche Summary
On Wednesday, the North Rockies Feild team reported and wind slab size 1 from an East aspect at treeline. Observations were limited due to poor visibility.
New snow and strong winds shifting from the southwest to northwest have likely formed fresh and reactive wind slabs on leeward slopes at treeline and in the alpine.
Loose snow avalanches within the new snow can be expected from steeper slopes and terrain features, especially if the sun comes out.
Give cornices a wide berth from above and below. Strong wind and solar radiation may increase the chance of cornice failures.
Snowpack Summary
Winter weather returns with new snow 10-20 cm across the region. Strong wind from the southwest to the northwest has likely formed fresh and reactive wind slabs on leeward slopes and behind terrain features. The new snow sits on a series of melt-freeze crusts on all aspects below 1900 m and southerly aspects to mountain top. On North aspects in the alpine, the new snow will sit on dry wintery and wind-affected snow surfaces.
The recent warm weather is expected to have helped old persistent weak layers heal, including a few crusts buried over the last month as well as a facet layer 150 cm deep from the mid-February cold snap.
Terrain and Travel
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Use ridges or ribs to avoid areas of wind loaded snow.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Watch your sluff: it may run faster and further than you expect.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
New snow and strong southwest to northwest wind will likely form fresh and reactive wind slabs in immediate lees of ridgecrests and roll-overs at upper elevations.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are especially fragile this time of year, especially when the sun is out. Cornice falls are dangerous on their own and they can also trigger slabs on slopes below.
Aspects: North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 9th, 2021 4:00PM
