Regions
Kootenay Boundary.
Confidence
Poor - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
There is a high degree of uncertainty with regard to the weather forecast right now. Two cold fronts will affect the region this weekend bringing lowering freezing levels and an uncertain amount of precipitation. The following is my best shot at a forecast for the region. You will notice that the ranges are wide to accommodate the uncertainty. Light precipitation begins to fall Friday evening continuing through Saturday morning. 10 - 20cm are expected. Freezing levels top out around 2200 meters Friday afternoon. Saturday: Snow continues through the day Saturday, 10 - 20cm are expected during the day. Freezing level holds steady near 1500m Saturday with winds out of the SW strong at ridgetop, light to moderate near treeline. Sunday: Continued snowfall Sunday through early Monday morning, 10 - 15cm expected during this period. Freezing level starts near 1500m falling to 500m by Monday AM. Winds similar to Saturday; SW strong at ridgetop, light to moderate near treeline . Very little precip is forecasted Monday & freezing levels remain near the valley bottom. Winds stay out of the SW, light to moderate at treeline, moderate to strong at ridge top.
Avalanche Summary
Several natural avalanches were reported Thursday to size 3. One noteworthy event was a size 2 avalanche that was triggered by cornice fall. The size 2 ran 50m before triggering a size 3 avalanche in lower angle terrain. The crown was reported to be 200cm in depth, failing on the Feb. 08 SH. One reported avalanche was remote triggered from 20m away on a 35 degree slope. Neighboring regions continue to report very large natural and human triggered avalanches.
Snowpack Summary
Recent storm snow amounts were approximately 40 cm in the east and 10 cm in the west, with the snow line at approximately 1600 m. The Valentines day surface hoar layer is now buried beneath as much as 120 to 140 cm! Stability tests show the deep layers are hard to trigger but there's huge potential for propagation.
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.
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.