Archived

Avalanche Forecast

Jan 22nd, 2014–Jan 23rd, 2014

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Rockies.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

A ridge of high pressure will continue to dominate the region bringing mainly clear skies and dry conditions for the forecast period. On Thursday the freezing level should hover at about 1500m, but another inversion will set in for Friday and Saturday with above freezing alpine temperatures. Winds should remain mainly light and west/northwesterly for all three days.

Avalanche Summary

Isolated wind slabs to size 1.5 were reported to have been triggered in the Elk Valley South area. They occurred in response to new snow on Tuesday night.

Snowpack Summary

Light amounts of new snow overlie a variety of surfaces which include: old, stubborn wind slabs in exposed terrain, well developed surface hoar in sheltered areas or a melt-freeze crust on steep, previously sun-exposed slopes. In exposed terrain, the new snow may have been distributed into small windslabs. The main concern in the region appears to be weak buried facet crystals. The facet layer, which exists in the mid or lower snowpack (depending where you are in the region), was responsible for some serious close calls last week. Although activity at this interface has tapered-off, this persistent problem has potential to re-awaken with warming forecast for the next few days. Other possible triggers for this layer include cornice fall, or a heavy load over a thin spot.

Avalanche Problems

Wind Slabs

Light amounts of new snow may exist as a new wind slab in exposed lee terrain. Watch for increased reactivity where the new snow overlies freshly buried surface hoar.

Be careful with wind loaded pockets>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Deep Persistent Slabs

Warming forecast for the next few days may re-activate weaknesses buried deep in the snowpack. Although less likely, avalanches on these layers could be quite destructive.

Avoid convexities or areas with a thin or variable snowpack.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely

Expected Size: 2 - 4