Avalanche Forecast

Fair - Freezing levels are uncertain on Friday

Synopsis:  The true pineapple breaks down Friday and a more zonal flow builds in its place which opens the door to a series of weak systems. Friday:  Freezing Level 1300m.  Precip: 2-5mm Wind: Light, SESaturday:  Freezing Level 900m.  Precip: 4mm Wind: Moderate SW gusting to StrongSunday: Freezing Level 1100m in the afternoon, dropping to the surface overnight.  Trace of precip.  Wind: Light, NE

Quite a few observations of a natural cycle to size 2.5 at upper elevations on Wednesday were received.  Both slab and loose snow avalanches were running on all aspects at the new/old snow interface down around 50 cm in depth.  It's no surprise that explosive control work in the region also produced avalanches to size 2.5 on most aspects as well. 

The storm has delivered around 50 cm of heavy snow at upper elevations as of Thursday morning and another 15 - 25 are expected this afternoon and evening. Strong southerly winds in the alpine have created slabs on N - E facing slopes that may be up to a meter in depth.  At treeline the storm snow is a messy configuration of dry snow, moist snow, rain soaked snow and even the occasional thin crust.  As this interface cools in the coming days the ski quality may be less than premium. This new snow is bonding poorly to the previous snow surface, which includes faceted snow, surface hoar, and/or a crust, but is most concerning where surface hoar is sitting on a crust on previously sun-exposed sheltered treeline slopes. Around a metre below the snow surface is a layer surface hoar buried on February 20th. Although this layer has a history of producing large avalanches, triggering this layer has now become difficult, and would most likely require a very large trigger on a steep, unsupported slope. Below this interface, the snowpack is strong and well settled.