Investigate the bond of recent snow and older surfaces, especially where the snow has been stiffened by wind - in some areas it sits on a crust, and other areas possibly surface hoar.
20 cm snow of recent storm snow at upper elevations may sit over a rain crust and/or possibly surface hoar. Human triggering is more likely where the snow had been exposed to wind. Loose dry sluffs may run fast from your boards or sleds in steep sheltered terrain.
Saturday night: Scattered flurries, light southwest ridge top wind, freezing level valley bottom.
Sunday: Scattered flurries, light to moderate southwest ridgetop wind, alpine high -7, freezing level valley bottom.
Monday: Partly cloudy, light northwest wind, alpine high -7, freezing level valley bottom.
Tuesday: Up to 5 cm new snow, moderate southwest wind, alpine high -7, freezing level 500 m.
On Friday, this great MIN from around Nelson reported a skier accidental size 1 wind slab sliding on the crust. On Wednesday there were some reports of ski cutting size 1 storm slabs over the crust in open treeline and alpine elevations.
Please submit your observations to the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
Wednesday's storm deposited 6-20 cm of snow. At low to mid elevations early in the storm, light rain is reported to have destroyed some surface hoar and in most places left a freezing rain crust in its place before things cooled and covered it with the remaining storm snow.
There is less known about upper elevations where the new snow may have been more wind affected and sit on a variety of surfaces such as crusts, surface hoar and old wind polished snow. If you have found buried surface hoar from December 8th, we would love to hear about it in the Mountain Information Network.
The early November crust is sitting about 10-30 cm up from the ground. There is a late November crust in the midpack in some places as well. Uncertainty with these crusts exist due to limited observations, but there haven't been any recent avalanches reported on these layers in this region.
Snowpack depths vary with elevation, treeline averages between 50-100 cm.
