Avalanche Forecast

Issued: Apr 16th, 2014 3:00PM

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

Alberta Parks matt.mueller, Alberta Parks

Temperatures are a huge factor in the snowpack stability these days. Traveling in the colder part of the day is essential. The large avalanche reported yesterday (see forecast details for more) is a sign of how much the sun can weaken the snowpack.

Summary

Confidence

Good

Weather Forecast

Light snow for the next 3 days. Amounts are expected to be minimal due to the rapid settlement and warm temperatures. Moderate winds at 3000m and light winds at valley bottom. The temperatures will rise throughout the next 36hrs with almost no overnight cooling.

Avalanche Summary

No new avalanches were noted today. A report came into the office today of a very large, surprising avalanche from one of our neighboring areas. The report said it was a remotely triggered, sz3.5 avalanche on a steep south facing, alpine slope. The failure plain was on ground.

Snowpack Summary

In alpine areas, almost 20cm's of new snow has fallen in the last 24hrs. The northern areas of the forecast region have seen the most accumulation with elevation playing a large role in snow depth. The winds have been low enough to limit the wind transport in the alpine. The sun on the other hand has enough strength to get through the thick cloud. By 1200hrs south aspects were softening at all elevations. The underlying surface tend to be crusts in various forms. Northern aspects have a frozen crust as a midpack, while the southern areas have a softer, partially frozen midpack. By 1300hrs today, the snowpack was still supportive.

Problems

Persistent Slabs

An icon showing Persistent Slabs
This layer has not been active in over a week now. Good test results and no activity leads us to believe this layer is almost inactive. The only hesitation is in shallow areas that are north facing at treeline and above. It is down 80-100cm.
Carefully evaluate and use caution around thin snowpack areas.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
The clock is ticking for this layer to wake up and become active again. A sudden rise in temperature has the potential to break the mid pack down and trigger the basal layers. Pay very close attention to solar effect and air temps.
Be aware of thin areas that may propogate to deeper instabilites.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

4 - 6

Valid until: Apr 17th, 2014 2:00PM