The main concern today is storm snow slabbing up. Sunny skies and strong solar radiation could result in increased avalanche activity. Tomorrow a strong system is expected to bring more snow and loading to the area.
Weather Forecast
An upper ridge will build over the province today, bringing dry but windy conditions. Freezing levels will rise to 1500m, and solar radiation will become a factor. Another low will move into the area on Wednesday bringing moderate to heavy precipitation and strong SW winds.
Snowpack Summary
Intense but intermittent flurries yesterday with locally very strong winds has added more load to the snowpack. Up to 35 cm of snow is beginning to slab up, especially in the alpine. Below 2000 meters, this storm snow sits on a sun crust formed on March 16. The mid-pack remains well settled. The Feb 12 PWL can still be found, but is stubborn.
Avalanche Summary
Numerous new slab avalanches were noted yesterday, associated with the new storm snow and strong winds, in the alpine and treeline. Several skier triggered avalanches were triggered in the Hermit area two days ago to size 1.0. These were low density slabs sliding on a crust down 15cm with surprisingly wide propagation running far and fast.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Wednesday
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.