Avalanche Forecast

Issued: Apr 2nd, 2013 4:51PM

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

rupert wedgwood, Parks Canada

Jasper.

Start early and be off all avalanche slopes by mid afternoon. Afternoon closures along the Maligne Lake road are possible over the next few days.

Summary

Weather Forecast

Cooling temperatures with no significant precipitation during the next 24 hours. Winds will be westerly in the light to moderate range. There will be sunny breaks during the day on Wednesday.

Snowpack Summary

Below Treeline a 15cm melt-freeze crust sits above wet and unconsolidated snow and provides stability. This condition demission with elevation and on slopes which are not South facing. By mid afternoon, or earlier on very hot days, this crust has melted and the avalanche danger is elevated considerably. The base of the snowpack is weak.

Avalanche Summary

Avalanche activity will be at its greatest by mid afternoon. During the morning a strong crust sits on the snowpack and prevents natural avalanches. As the crust melts the danger increases. At that time avalanches up to size 2 can be expected. Falling cornices can trigger full snowpack slabs of size 3 from the alpine. Cool temps reduce the danger.

Confidence

Freezing levels are uncertain on Wednesday

Problems

Cornices

These heavy and unstable features can fall unexpectedly triggering deep large avalanches. These are commonly, but not exclusively, found above east facing slopes at ridge top elevations.

Avoid steep slopes below cornices.Stay well back from cornices.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

Cooling temperatures over the next 3 days will reduce magnitude, frequency and distribution of of these events. Pay close attention to the increasing air temperature and met freeze crust thickness. Once gone you should head for safe slopes.

Start and finish early before the surface crusts melt.Travel early on frozen crusts before the heat of the day.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Wet Slabs

These events have been observed up to 2600m on south facing slopes. Cooler temps over the next few days will reduce the magnitude and distribution. Like loose wet avalanches these events are most likely in the afternoon when the sun is out.

Avoid shallow snowpack areas where triggering is more likely.Finish ice climbs early in the day before the temperature rises.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 3rd, 2013 4:00PM