Avalanche Forecast
Regions: North Columbia.
Strong wind and new snow 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.
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
Unsettled weather continues with more snow, strong winds, and seasonally cool temperatures.
Friday: Cloudy with light snow 10-15 cm. Ridgetop wind moderate to strong from the southwest. Alpine temperatures near -11 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 900 m.Â
Sunday: A mix of sun and cloud with light ridgetop wind from the northwest. Alpine temperatures -9 and freezing levels 1400 m.Â
Avalanche Summary
No new reports on Wednesday besides loose snow sluffing in steep terrain with skier traffic.
New snow and strong wind from the southwest to the northwest have likely formed reactive wind slabs on leeward slopes at treeline and in the alpine.Â
Loose snow avalanches within the new snow may occur from steeper slopes and terrain features, especially in locations that received greater accumulations of new snow.
Snowpack Summary
Winter weather returns with new snow 10-30 cm across the region. Shifting wind directions from the southwest to northwest will likely form new 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 snow surfaces and possibly surface hoar on wind-sheltered slopes. It may have a poor bond to the old snow surfaces, especially the crusts.Â
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
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Dial back your terrain choices if you are seeing more than 20 cm of new snow.
- 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.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Avalanche 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 East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2