Avalanche control is planned for the Icefields Parkway between Saskatchewan Crossing and Parker Ridge on Tuesday. Estimated road closure in this area is 1030 to 1600.We are expecting the sun to be quite intense on solar aspects tomorrow.
Weather Forecast
We are expecting the sun to pack a punch tomorrow with treeline and below treeline solar aspects to be most affected. Snow returns at the weekend with some models giving up to 20cm in the Icefields area.
Snowpack Summary
Variable distribution of recent storm snow, with the deepest amounts in the 45cm range in the Columbia Icefields area. Minimal wind affect other than exposed areas at upper elevation. Feb10 interface is down 60-90cm and has been dormant recently. Lots of snow available for transport.
Avalanche Summary
Avalauncher control work in the Medicine Lake area yesterday produced several size 2.5 slabs which ran to the lower third of the path and numerous loose dry slides to size 2. Road patrols in the Columbia Icefields area had limited visibility but did report some small slides on solar aspects in the afternoon.
Confidence
Timing or intensity of solar radiation is uncertain on Tuesday
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.