Confidence in the track and timing of incoming precipitation is fair. The region may receive heavier amounts of precipitation than forecast. If this occurs, expect the danger ratings to be elevated.
Confidence
Fair - 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-heavy amounts of precipitation to the BC interior Wednesday night into Thursday and Friday. Ridgetop winds will start light-moderate from the South, switching moderate SW through Thursday. Freezing levels will fall to 1800 m. Light-moderate precipitation expected for Friday. 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 to 2000 m. Confidence is poor for Thursday/Friday due to the uncertainty of the lows location in Alberta. This could potentially bring more than anticipated precipitation amounts to the regions.
Avalanche Summary
On Wednesday many loose wet avalanches were reported up to size 2. A significant size 3 wet slab was also seen on a south aspect before lunch time.
Snowpack Summary
Mild temperatures have settled out much of the upper snowpack. Spring-like conditions prevail; with surface crusts on solar aspects and melt conditions (no overnight re-freeze) on all aspects below 1700 m. Cornices are large and exist on most ridgelines. I don't expect this to be an immediate problem until it heats back up again, possibly Saturday. Up to 100 cm sits on the March 27th interface. This interface consists of a buried sun crust on southerly aspects and a temperature crust on more northerly slopes. A thin layer of facets and or surface hoar can be found on this crust on all aspects. The bond on this interface seems to be improving. The mid-pack is well settled and strong. At the base of the snowpack sits a weak layer of facets and depth hoar. I'd be suspect of steeper unsupported slopes where the snowpack goes from thin to thick.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.