Avalanche Forecast

Issued: Mar 11th, 2015 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is moderate. Known problems include Wind Slabs, Loose Wet and Deep Persistent Slabs.

mike eder, Parks Canada

Jasper.

A change in weather such as extended sunny periods, rain or warm overnight temperatures will increase the avalanche danger.

Summary

Weather Forecast

Up to 10 cm of snow is expected through to Saturday in the Icefields area. Freezing levels are forecast to stay near 2000m overnight which will produce poor recovery in valley bottoms leading to additional melting and isothermal conditions.

Snowpack Summary

A supportive mid pack consisting of rounded and facetted layers is bridging the weak depth hoar/facet layers that make up the lower snowpack. Wind slabs have formed in sheltered alpine locations from moderate to strong SW winds. Below treeline, poor overnight recovery has created isothermal conditions in valley bottoms.

Avalanche Summary

One size 2 SL was observed in the alpine in the Saskatchewan river valley as well as several loose size I avalanches on solar aspects.

Confidence

Intensity of incoming weather systems is uncertain on Thursday

Problems

Wind Slabs

Previous moderate SW winds have created slabs on sheltered aspects and cross loaded features in the alpine.

Be cautious as you transition into wind affected terrain.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

Overcast conditions and high freezing levels will prevent any overnight refreeze of the snow pack at lower elevations. As such, solar aspects BTL could be prone to loose snow slides whenever the sun makes an appearance.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

Natural and human triggering is unlikely but it is still a good practice to avoid steep, open, rocky slopes with a shallow snowpack.

Caution around convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 12th, 2015 4:00PM