Despite the cold and snowy look outside, not much new snow has actually fallen. 2-5 cm over the past 24 hours with the deepest amounts near Banff. Wednesday will be windy (and cold), so expect drifting to create small, easily triggered soft slabs and dry loose avalanches. Climbers prepare for spindrift and watch for sluff volume in the gullies.
5-10 cm of very low-density snow has fallen over the past few days and now will be blown into soft windslabs that'll be easy to trigger but small in size. Watch for these on the immediate leeward side of ridges. They could be about 20 cm deep and will release easily.
A 20-60 cm slab sits over a persistent weak layer of basal facets, buried sun crusts, or isolated pockets of surface hoar. This layer is unpredictable and will be around for some time to come.
Cold, low-density snow with no cohesion now clings to the cliffs and trees and will sluff off easily from the wind. These avalanches will not be large but could collect in gullies with enough volume to knock a person over.
No new avalanches were observed or reported today, but field observations were minimal with the obscured sky.
Here is an image of the typical snowpack in the Rockies today; 81 cm snowpack at treeline at Crowfoot Glades. Note the 1 cm of low-density new snow on the surface, then about a 20-30 cm slab overlying the Nov 22 interface, below which facets and weak snow grains exist to ground. This snowpack is generally weak and will not handle much extra load.
The cold, NW flow persists as a ridge of high pressure dominates BC and a low-pressure system sends cold, moist air down the east side of the mountains. The story for the next 24 hours is the wind, which will transport snow. Expect a windy day on Wednesday with gusts reaching 80 km/hr from the west, trace amounts of snow and continued cold temperatures.
More details can be found in the Mountain Weather Forecast.
