Avalanche Forecast

Issued: Mar 29th, 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.

catherine brown, Parks Canada

Glacier.

Warm temperature and strong sun will change conditions rapidly this afternoon. Stable conditions this AM will deteriorate quickly surfaces become moist. Loose avalanche are likely this afternoon, reduce your exposure to sun effected terrain.

Summary

Weather Forecast

Sunny conditions with light/calm winds are forecast today. Freezing levels will rise to over 2000 m, expect +4 deg C in the alpine today. Spring conditions will continue through the weekend with elevated freezing levels. No precipitation is forecast during this period.

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. Several PWL's (mostly buried sun crusts with SH) are still active.

Avalanche Summary

Afternoons have seen small loose avalanche cycles mostly concentration to SE-W asp. Yesterday after 1300 avalanches were running up to size 2.5, with one notable size 3.0. Most of these are scrubbing the surface snow, but a few are digging into deeper layers. Cornice triggered avalanches have increased, with warm daytime temperatures.

Confidence

The weather pattern is stable

Problems

Loose Wet

The sun will be strong today. Avoid terrain traps where moist slides could pile up deeply. Solar triggered avalanches are most likely around exposed rocks and may trigger deeper slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Cornices

Cornices are large and unsupported. Large swings in day/night temperatures increases their fragility. Very warm afternoon temps will make them weaker. Cornice triggered large avalanches are possible.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 4

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.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 30th, 2013 8:00AM