Regions
Kootenay Boundary.
Warmth remains the main driver of avalanche hazard as we shift into a more spring like pattern. Minimize your exposure to large slopes if the snowpack is becoming moist or wet.
Weather Forecast
Thursday: Freezing level starting around 1000m, rising to around 1700m in the afternoon. Light NW/W winds at all elevations. Few clouds in the morning increasing to 60% cloud cover in the afternoon.Friday: Freezing level starting near 1000m, rising to approximately 1700m in the afternoon. Light SW winds at treeline, moderate SW winds at ridgetop.Saturday: Freezing level starting near 1300m, rising to 1500m in the afternoon. Light SW winds at treeline, moderate SW winds at ridgetop.
Avalanche Summary
No new activity to report from Tuesday. On Monday warm temps led to a natural size 2 wet slab failure that ran on a steep NE facing feature near 2200m.
Snowpack Summary
The region experienced it's second overnight temperature recovery in a row Tuesday night. This time the night brought freezing temperatures that much closer to the valley floor; an overnight low of -2c was recorded at 850m. This resulted in the formation of a surface crust that was already reported as being supportive Monday. This crusts sits on top of 3 to 10cm of moist snow which overlies the March 24th crust that is up to 20cm thick. Below this crust there is 15 to 60cm of snow that is likely still moist from the previous rain event. This moist snow is reportedly bonding well to the mid-March crust/facet complex. The mid and lower snowpack are strong and well settled.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.