Avalanche Forecast

Issued: Mar 30th, 2013 8:00AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Loose Wet, Cornices and Persistent Slabs.

Parks Canada catherine brown, Parks Canada

Avalanche danger will increase this afternoon on sun effected terrain.  Plan your trip to take advantage of good skiing and lower danger on sheltered north and east aspects.  Avoid exposure to solar facing terrain as it heats up.

Summary

Weather Forecast

Mild and sunny conditions are forecast through Monday. No precipitation is expected with light NW winds.  Freezing levels today will rise to around 2400 m with alpine temps ~ +5.

Snowpack Summary

Strong solar radiation and rising freezing levels have deteriorated ski quality on all but sheltered N aspects. Moist surface snow and crusts are found at all elevations, with growing surface hoar.  Avalanches have been triggered from thin snowpack areas weakened by warm temps.

Avalanche Summary

Afternoons have seen small loose avalanche cycles mostly concentration to SE-W asp. Most of these are running in the surface snow. Below treeline and shallow exposed terrain with isothermal snow are weak and can be skier triggered. Cornice failures are still possible, recently not many failures have triggered avalanches.

Confidence

The weather pattern is stable

Problems

Loose Wet

An icon showing Loose Wet
The sun will be strong again today. Avoid terrain traps, especially below treeline, where moist slides could pile up deeply. Solar triggered avalanches are most likely around exposed rocks and may trigger deeper slabs.
Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Cornices

An icon showing Cornices
Cornices are large and unsupported. Large swings in day/night temperatures increases their fragility. Cornice triggered large avalanches are possible.
Avoid steep slopes below cornices.Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Persistent Slabs

An icon showing Persistent Slabs
Buried weak layers are stubborn to fail, but should not be discounted. Slopes receiving direct sun become more reactive during the day with warming. This is most likely on steep solar aspects where buried crusts exist.
Conditions are greatly improved, but be mindful that deep instabilities are still present.Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Mar 31st, 2013 8:00AM