A persistent problem in the snow pack, makes up the top 30 to 50cm. Field teams have been monitoring the changing sensitivity of these layers carefully, as should you!
Weather Forecast
A strong SW flow with a series of low pressure storm cells tracking west from BC will continue bringing unsettled weather and light snow through the week for a forecasted total of 20 cm. Wednesday, expect as much as 10cm overnight the through the morning Thursday. Alpine High -6C. Ridge wind light to moderate SW, gusting to moderate values.
Snowpack Summary
Windslab continues to build in open areas and has covered two surface hoar layers in the top 30 to 50cm of the snowpack. The distribution of this SH in the terrain has been found in immediate lees of wind swept features, around TL and into the alpine. Field teams will continue to monitor the sensitivity of these layers carefully, as should you!
Avalanche Summary
Natural avalanches up to size 1.5 were observed Tuesday in windswept alpine moraine features. Appears to be running on the persistent slab interface dow 30 to 50cm.
Confidence
Intensity of incoming weather systems is uncertain on Wednesday
Problems
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.
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.