Archived

Avalanche Forecast

Apr 2nd, 2013–Apr 3rd, 2013

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

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

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: South Coast.

Confidence

Fair

Weather Forecast

Synopsis: The upper ridge of high pressure rebuilds on Wednesday resulting in more sun through Thursday morning. The ridge gives way to a low pressure system later on Thursday bringing moderate to heavy precipitation and rising winds. Wednesday: A mix of sun and cloud. The freezing level is around 2000 m and winds are light from the southwest. Thursday: Increasing cloud with precipitation developing in the afternoon. The freezing level drops to around 1800 m. Winds increase to moderate of strong from the southwest. Friday: Moderate precipitation. The freezing level is around 1600 m and winds are moderate to strong from the southwest.

Avalanche Summary

Loose wet avalanches up to size 2 continue to be reported on solar aspects.

Snowpack Summary

Recent warm temperatures have created melt freeze conditions on all aspects below 2000m and to mountaintop on south facing terrain. Isothermal conditions as deep as 100cm have been reported on South aspects at lower elevations. On high north-facing slopes surfaces are well settled and surface hoar development continues in some areas. Cornices are huge!A layer of surface hoar (buried on March 11; now down about 60 cm) is still being observed in some locations. Triggering this layer has become unlikely, and would most likely require a large trigger or from a thin snowpack zone. Mid and lower snowpack layers are well bonded.

Avalanche Problems

Loose Wet

Loose wet avalanches are likely on steep south facing slopes if the sun is shining.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Cornices

Cornices are large and become more susceptible to failure due to warming. A cornice fall could possibly trigger a slab on slopes below.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 6