Archived

Avalanche Forecast

Apr 5th, 2012–Apr 6th, 2012

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

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

Regions: South Columbia.

Confidence

Good

Weather Forecast

FRIDAY: Broken skies with locally light convective precipitation. Winds are light from the north and switching to the east in the afternoon. Freezing level hovering at 1600m. SATURDAY: A ridge of high pressure builds giving way to broken skies. Light southerly winds. Freezing level 1000-1200m. SUNDAY: The high pressure continues giving mostly clear skies and light west winds. Freezing level rising to 1600m.

Avalanche Summary

Recent reports are generally smaller avalanches (size 2) that are either wind slabs or moist loose slides due to solar warming. Previous reports from last weekend or early in the week include remotely triggered size 3 and a natural avalanche with a 2 km wide crown was reported on an east facing aspect which started in the storm snow and then stepped down to the March 27th crust/facet combo. These shouldn't be forgotten quite yet.

Snowpack Summary

Recent snow accumulations range from 20-40cm in the past 48hours. 90-120cm of snow from the past 7 days is now sitting on a reactive weak layer over a crust. Slopes below 1000 m continue to experience little or no overnight refreeze (recovery). The deeper early february surface hoar layers seem to have been unreactive in the short term but still remain a concern with very heavy triggers such as a cornice fall.

Avalanche Problems

Storm Slabs

Bigger avalanches relating to a crust 40 to 80 cm deep especially on south facing slopes. Watch the sun and afternoon warming.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 5

Wind Slabs

Recent new snow combined with moderate winds creating new windslabs on northerly downwind slopes and cross-loaded terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4

Cornices

Large cornices keep getting bigger and more sensitive with continued wind, snow and warm temperatures. Cornices impacting slopes below could be considered enough of a load to trigger some of the deeper buried weaknesses.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 3 - 7

Loose Wet

Short periods of sun can be enough to trigger avalanches on sun exposed slopes.

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4