Avalanche Forecast
Issued: Apr 6th, 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
Wintery weather returns with new snow and strong wind on Wednesday. Fresh wind slabs may be reactive on lee slopes at upper elevations.
Loose-dry avalanches will likely occur from steep slopes and terrain features.
Summary
Confidence
Weather Forecast
Tuesday Night: Cloud cover starts to develop. Ridgetop wind moderate from the southwest and freezing levels 1200 m.
Wednesday: Snow amounts 10-20 cm. Ridgetop wind strong from the southwest. Alpine temperatures near -5 and freezing levels 1500 m.
Thursday: Mostly cloudy with light snow 5-10 cm. Ridgetop wind light from the southwest. Alpine temperatures near -5 and freezing levels 1200 m.
Friday: Snow 5-10 cm. Ridgetop wind moderate to strong from the South. Alpine temperatures near -8 and freezing levels 1200 m.
Avalanche Summary
On Tuesday, a skier-triggered cornice failure size 2.5 was reported from a high alpine ridgeline along with some wet loose avalanches up to size 1.5.
On Monday a size 3 natural wind slab was reported on a North aspect at 2400 m. Additional reports of natural loose wet avalanches up to size 1 were seen from most solar slopes in the alpine and cornice fall size 2-2.5 on a northeast aspect.
With forecast snow and strong southwest wind on Wednesday, wind slabs may be reactive on leeward slopes, and natural loose-dry sluffing seen from steep terrain
Snowpack Summary
Winter weather returns with light to moderate forecast snow amounts accompanied by moderate wind through the forecast period. Fresh wind slabs may build through the day on Wednesday. The new snow sits above surface hoar crystals on sheltered north facing terrain above 1900 m, a series of melt-freeze crusts on all aspects below 1900 m, and a sun crust on the southerly aspects to mountain top. Below 1500 m the snowpack is quickly diminishing.
Loose–dry sluffing will likely occur on steep slopes and terrain features where the new snow has a poor bond to the underlying old surfaces.
At alpine and treeline elevations, a widespread crust exists (except on north-facing slopes above 1800 m) buried 50-100 cm deep. Overall the snow seems to be bonding well at this interface, although there have been a few isolated avalanches running on deeper crust layers over the past few weeks.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Problems
Wind Slabs
New snow and strong southwest wind may form fresh wind slabs on Wednesday. They will be most likely be isolated to immediate lees of ridgecrests and roll-overs in wind-exposed alpine terrain.
Loose-dry sluffing of the new snow can be expected from steeper slopes and terrain features.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are especially fragile this time of year. Cornice falls are dangerous in their own right and they can also trigger slabs on slopes below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 7th, 2021 4:00PM
