Avalanche Forecast

Archived

Mar 27th, 2021–Mar 28th, 2021

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Purcells.

Avalanche danger will increase through the day as new snow and wind build fresh slabs. If you see more than 25 cm of new snow in your riding area, treat avalanche danger as one step higher at alpine and treeline elevations.

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Saturday night: Flurries bringing 5-10 cm. 30-50 km/h southwest wind. Freezing level 2000 m. Alpine temperatures around -5 C.

Sunday: Scattered flurries with up to 10 cm of snow in most areas and upwards of 20 cm in hot spots along the central west border of the region like the Bugaboos. 40-60 km/h southwest wind, Freezing level 1800 m. Alpine temperatures around -5 C.

Monday: Another 5-10 cm of snow by the morning then cloudy with isolated flurries during the day. 20 km/h northwest wind. Freezing level valley bottom. Alpine temperatures around-12.

Tuesday: Mix of sun and cloud. 20 km/h northwest wind. Freezing level 1500 m. Alpine temperatures around-8.

Avalanche Summary

No new avalanches have been reported since Thursday. Recent avalanche activity has been limited to small (size 1-1.5) wind slab avalanches, dry loose sluffs, and cornice falls. These have occurred on a range of aspects, and will continue to be possible on wind-loaded or sun-exposed slopes.

Snowpack Summary

5-20 cm of snow accumulates over isolated wind slabs, soft dry snow on shady sheltered slopes and moist and crusty surfaces on sun exposed slopes. A widespread crust layer from the mid-March warm spell can be found 20-50 cm deep, and small surface hoar has been observed at this depth on some isolated north-facing slopes. Reports suggest the snow is generally well bonded to these layers. Deeper layers are strong and have been unreactive over the past few weeks.

Terrain and Travel

Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
Dial back your terrain choices if you are seeing more than 25cm of new snow.
The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.