Archived

Avalanche Forecast

Apr 13th, 2014–Apr 14th, 2014

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

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: Northwest Inland.

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Monday

Weather Forecast

Monday: Clear skies in the morning with increased cloud and light precipitation possible late in the day / Moderate southwest winds / Freezing level at about 1700mTuesday: Light to locally moderate snowfall / Moderate southwest winds becoming light and northerly / Freezing level at 1000mWednesday: Mix of sun and cloud / Light northerly winds / Freezing level at 1300m

Avalanche Summary

At the time of publishing no new avalanches were reported, although I suspect natural loose wet and slab activity may have occurred with Sunday's warm temperatures.

Snowpack Summary

Last week up to 30 cm of snow fell at upper elevations. At lower elevations rain saturated the snowpack and melt-freeze conditions exist up to 1200 m on all aspects. At higher elevations the new snow overlies a rain crust which exists to about 2000m. Strong SW winds have built thick wind slabs on leeward aspects and recent test results indicate touchy conditions still exist. Cornices are also large and becoming weak with daytime warming.The early February crust/facet layer is down 150 - 200 cm. This destructive layer should remain on your radar, and could become reactive with solar radiation and high freezing levels.

Avalanche Problems

Wind Slabs

Recent storms have formed hard and reactive wind slabs in the lee of upper elevation terrain breaks. Cornices are also large and may become weak with warm spring temperatures.

Extra caution needed around cornices with current conditions.>Make observations and assess conditions continually as you travel.>Watch for areas of hard wind slab in steep alpine features.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Deep Persistent Slabs

Deep persistent avalanches would be very large and highly destructive. Possible triggers include cornice fall, a surface avalanche in motion, warming and intense solar radiation.

Be aware of the potential for large, deep avalanches due to the presence of buried facets and surface hoar.>Minimize overhead exposure; avalanches triggered by warming and/ or cornice fall may run farther and faster then expected.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 3 - 5

Loose Wet

Watch for loose wet avalanches with daytime warming on steep, sun-exposed slopes. Loose wet avalanches can be pushy and entrain mass quickly.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3