Confidence is poor due to disagreeing weather models, track and timing of the low moving into Southern Alberta. 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
Weather Forecast
A low pressure center sitting SW of Montana will continue to move SE, this should be arriving in Southern Alberta by Thursday afternoon. Depending on timing and track, this low may spread moderate amounts of precipitation to the BC interior Wednesday night into Thursday. Ridgetop winds will start light-moderate from the South, switching moderate SW through Thursday. Freezing levels will fall to 1800 m. Some lingering flurries may exist into Friday with freezing levels near 1500 m. The weekend will see a fairly inactive ridge of high pressure dominating the interior, bringing sunny skies and freezing levels up to2500 m. Confidence is poor for Thursday/Friday due to the uncertainty of the lows location in Alberta. This could potentially bring more than anticipated (moderate) precipitation amounts to the regions.
Avalanche Summary
Loose snow activity on a SE facing slopes have occurred. Most of this consists of pinwheeling, and point release avalanches involving the surface snow, no slabs.
Snowpack Summary
Spring like warm weather has promoted settlement and bonding within the snowpack. Melt-freeze conditions are existing with moist snow below 1700 m on all aspects, and to ridgetop on solar aspects. Below the surface, down 60-120 cm sits on the March 27th interface. Our field team was out in the region last Saturday; they were able to find the March 27th interface down around 90cm but test profiles did not produce any results on this layer. They were also out on Tuesday, found the layer again which seems to be more prominent on southerly aspects where the crust is thicker. The upper snowpack seems to be bonding to this interface and may soon become dormant. 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
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.
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.