Confidence is poor due to disagreeing weather models, track and timing. The region may receive heavier amounts of precipitation than forecast. If this occurs, expect the danger ratings to be elevated.
Confidence
Poor - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
A low pressure center is moving into Southern Alberta where it should remain stationary through to Friday. This low will continue to spread light- moderate amounts of precipitation to the region through to later Saturday. Freezing levels on Friday are expected to rise to 2000 m. Through the weekend freezing levels will generally stay near 1900 m, rising to 2000 m by Monday. Solar radiation will be intense when the sun shines through. Ridgetop winds will be light-moderate from the SW-W.
Avalanche Summary
No new avalanche observation reported.
Snowpack Summary
On Thursday, up to 10 cm of new snow fell at upper elevations. With forecast snow and wind, wind slabs are likely building at higher elevations behind ridgecrests and terrain features. Lower elevations continue to see rain, and loose wet avalanches are likely. This recent spring- like warm weather has promoted settlement within the snowpack. Melt-freeze conditions exist, and snow is moist below 1700 m on all aspects. On solar aspects the snow has become moist to ridgetop and new snow may have a poor bond to the crust. Below the surface, down 60-100 cm sits on the March 27th interface which seems to be more predominant on southerly aspects. The bond on this interface seems to be improving, as field tests have shown no significant results. On Tuesday our field team went back to the Flathead to gather some observations. They found the mid Feb surface hoar layer down 280 cm, test results showed a Deep Tap Test of 21 with a sudden collapse characteristic. This layer currently sits dormant, but may wake up later this spring under a prolonged heat up. Glide cracks are a concern with the forecast rain below 1500 m. Be sure to give them a wide berth as they are very sensitive and could fail at any moment.
Problems
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.