Avalog Join
Archived

Avalanche Forecast

Apr 21st, 2012–Apr 22nd, 2012
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
Below Threshold
The avalanche danger rating in the alpine will be below threshold
Treeline
Below Threshold
The avalanche danger rating at treeline will be below threshold
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold

Regions: Cariboos.

Confidence

Fair - Due to limited field observations for the entire period

Weather Forecast

A warm front is expected to drift into the interior during Saturday evening bringing high cloud and freezing levels up to about 2000 metres. Some light precipitation is expected by Sunday morning, and the freezing level may only dip a couple of hundred metres to about 1700. Precipitation is expected to increase during the day on Sunday with about 5-10 mm forecast, and freezing levels rising to about 2300 metres.

Avalanche Summary

Natural moist and wet loose snow avalanches were reported from Friday up to size 2.0, some wet slab avalanches were also reported.

Snowpack Summary

On Thursday, moderate to locally heavy accumulations formed wind slabs at treeline and above on a variety of temperature-affected surfaces that include well settled powder, wet grains and crust sandwiches. Rain has continued to penetrate and weaken the isothermal snowpack at lower elevations. The mid-February buried surface hoar layer is down about 140-220 cm, although avalanches releasing on this layer represent an extremely low probability-high consequence scenario. Cornices in the region are very large. With spring temperatures, and direct solar radiation these are more likely to become weak and fail. They could provide a large enough trigger to release deep layers on slopes below. Average snowpack depth in the alpine remains in the 3 m range. For more information on Spring Conditions and ways to mitigate risk, please visit the new Forecasters Blog Post.

Avalanche Problems

Loose Wet

Snow stability can deteriorate very quickly with spring temperatures. Watch for loose wet avalanches on steep terrain, especially if the sun is shining.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 4

Wet Slabs

Buried crusts will provide an ideal sliding layer for wet slabs, especially on sun-exposed slopes. Warmer temperatures at lower elevations are also a contributing factor. Spring temperatures will also promote glide crack activity.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 5

Wind Slabs

New windslabs may develop due to forecast snowfall and southwest winds. Recent windslabs may not have bonded on some high alpine northerly aspects.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3