Archived

Avalanche Forecast

Feb 25th, 2016–Feb 26th, 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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

Regions: Glacier.

The sun's warmth packs a punch at this time of year. Use extra caution during the heat of the day, especially on sun-exposed slopes and around cornices.

Weather Forecast

It feels like spring. Cold temp's give way to daytime warming, with freezing levels rising to 1700m by late afternoon. No new snow and scattered clouds today, with light ridge-top winds. More of the same Friday, with a minor storm rolling through early Saturday, bringing up to 10cm of snow, mod SW winds, and freezing levels around 1600m.

Snowpack Summary

Solar aspects, SE through W, have been cooked by the strong sun the last few days, and a breakable crust is present to near ridge-top elevations. Polar aspects have remained cool and dry. Soft slabs in the upper 50cm can be found near ridge crests. The Feb 10th surface hoar/suncrust is down 60-100cm and is much less reactive than a few days ago.

Avalanche Summary

One loose sz 2 avalanche was observed from the W face of Sir Donald yesterday. It did not trigger any deeper layers once it hit the fan below the face. No new activity was observed in the highway corridor. Of note earlier in the week, there were BIG (up to sz 4) avalanches in the Asulkan & Loop valleys, likely cornice-triggered by solar warming.

Confidence

Avalanche Problems

Wind Slabs

Soft windslab can be found in immediate lee features in the alpine and at tree-line. These slabs are also present on exposed alpine features, like large convex rolls.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

Feb 10 interface lingers and is becoming difficult to forecast. In some areas there is surface hoar on a crust which is a good recipe for bad avalanches. It may become reactive given prolonged sun or added load such as cornice fall or slab avalanche

Be aware of the potential for wide propagations.Cornices become weak with daytime heating, so travel early on exposed slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 1 - 3