Avalanche Forecast

Issued: Feb 28th, 2013 8:33AM

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

mike.koppang, Alberta Parks

Kananaskis.

The Pineapple Express is on its way! We can expect temperatures to rise, winds to pick up and potentially 20cm of new snow. Be extra cautious and aware of rising temps and increasing hazard. MM

Summary

Confidence

Fair - Track of incoming weather is uncertain

Weather Forecast

The Pineapple Express is on its way! Temperatures are going to rise significantly overnight Thursday, and stay high for Friday & Saturday. Precip amounts associated with the Pineapple Express is still up in the air (sorry for the bad pun). Amounts may vary, but for now up to 18cm of snow can be expected at higher elevations, and there is potential for rain at valley bottom. To top it off, the winds will be rocketing out of the west. 120KM at 3000m. Batten down the hatches!

Avalanche Summary

Numerous moist avalanches and pinwheeling at TL on south aspects from yesterday. There was one natural cornice triggered avalanche (SZ 1) at 2400m, on a south aspect slope. No slab propagated, however it did entrain a fair amount on snow.

Snowpack Summary

HN 7cm at TL today. Moderate west winds have redistributed this storm snow making for variable amounts at ALP & TL elevations. The infamous windslab layers sit below this. At TL there are a variety of these slabs sitting on the hardslab, now down 50. In ALP areas, the hardslab is closer to the surface, and still exposed in certain areas. Tests revealed a moderate shear down 25 at TL, however the results were inconsistent from area to area. BTL the snowpack has gained some strength and is now supportive.

Problems

Wind Slabs

windslabs at treeline and above are still possible to trigger. Convex rolls in steep terrain below ridge crests and steep crossloaded gullies are particulary concerning. Expect to start finding these at the upper margin of TL.

Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Buried wind slabs (originally formed in late January) are still are concern in steep features in the alpine and at treeline. These slabs are found down 20 to 50cm in the snowpack and are likely more trigger-able from shallow snowpack areas.

Carefully evaluate and use caution around thin snowpack areas.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Mar 1st, 2013 2:00PM