With the improving weather it's time to keep enthusiasm in check and give the snowpack some time to settle before considering more aggressive terrain.
Confidence
Moderate - Due to the number of field observations on Friday
Weather Forecast
After a stormy week we'll have a bit of a break in the action through to Tuesday afternoon. Freezing levels have increased slightly in the latest forecast to stay between 1000m to 1200m for the period. We're expecting scattered flurries with 5-10cm during the day on Saturday as most of the active weather brushes by heading southeast of the region... but those numbers could easily double if the path changes. Winds at ridgetop will be 20 Km/hr from the southwest on Saturday, becoming light northerly on Sunday..
Avalanche Summary
We've slowly getting observations from the alpine post-storm and a widespread cycle of natural activity occurred. Explosives control on Friday pulled out some large avalanches ranging from size 2.5 to 4 on north/northwest aspects at 2150 metres. During the storm on Thursday, skiers were able to trigger small slides as low as 1400m elevation, well into the below treeline (BTL) zone. Storm slabs will likely remain touchy through Saturday.
Snowpack Summary
Snow depths increased rapidly during the week with 180-220 cm now at treeline. A significant change from even a week ago is that we are now above threshold for avalanches below treeline (think cutblocks and open areas in the forest), so heads up as you work your way towards treeline. All the new snow appears to be bonding well to the thick mid-November crust, and settling quickly. The mid to lower snowpack is well consolidated. In the alpine, snowpack depths are 240 cm plus and strong winds combined with the new snow created touchy slabs, especially on leeward slopes. Watch for weak layers and wind slabs on lee features before committing to a slope. Nice to see midweek posts to the Mountain Information Network... all observations are useful so please keep 'em coming!
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.
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.