Archived

Avalanche Forecast

Mar 7th, 2016–Mar 8th, 2016

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Purcells.

If you have been out in the mountains, please consider reporting your observations to the Mountain Information Network (MIN).

Confidence

High

Weather Forecast

Freezing level dropping to valley bottoms overnight. 2-3 cm of new snow combined with light winds overnight. Overcast with light precipitation on Tuesday combined with light winds and freezing levels rising up to 1500 metres. Chance of broken or scattered cloud on Wednesday with a good overnight freeze. The next pulse of stormy weather moving into the region on Wednesday night. Warm, wet, and windy on Thursday.

Avalanche Summary

A few small natural avalanches and a couple of size 2.0 explosives controlled avalanches were reported on Sunday. Natural wind slabs and storm slabs up to size 2.5 were reported on Saturday. Natural and explosives controlled avalanches up to size 2.5 were reported on Friday.

Snowpack Summary

Strong southerly winds have developed wind slabs in the alpine and at treeline. The 20-40 cm of recent storm snow is bonding poorly to a melt-freeze crust on previously sun-exposed slopes and lower elevation terrain, and/or a layer of surface hoar on shady and sheltered slopes at treeline elevations. The surface hoar and/or crust layer buried in mid-February is now down 50-80cm. The early January surface hoar/facet layer is typically down 70-120cm. Triggering an avalanche on this layer has become unlikely but it still has isolated potential to produce very large avalanches with a heavy trigger. In general, the lower snowpack is well settled and strong, apart from some thin snowpack areas where basal facets exist.

Avalanche Problems

Wind Slabs

Wind slabs continue to develop at higher elevations where there is snow available for transport. Watch for cross loaded slopes.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

A weak layer of surface that was buried on February 27th may be down 20-40 cm. This weak layer may be associated with a crust on solar aspects. The February 11th surface hoar layer is now down 50-60 cm and continues to be a concern.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Caution around convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 5