Purcells

This bulletin is based on a very small amount of data in a region that is incredibly varied in snow cover from north to south.  Start small and gather information in your travels before committing to anything with consequence.

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Pre-frontal winds out of the west will build to extreme at ridgetop Wednesday.  Very light snow is expected late in the day.  Very light snow will continue through the day Thursday and into Friday.  I expect around 10 cm of storm snow accumulation by friday afternoon.  Freezing levels should remain at valley bottom throughout the forecast period.

A few observations from last weekend have trickled in.  They mostly involve the November 17th surface hoar layer.  Riders triggered a few different avalanches on this layer with most of them coming in at size 1.5.  There is an unconfirmed report of at least one partial burial in the Quartz Creek area.  Thankfully, it sounds like everyone is okay.  Crown depth was around 40 cm. 

An incredible amount of variability exists in the region.  In the north the alpine snowpack is near 2 m in depth while the total depth of snow on the ground in the south is just over a foot.  Riders report that many slopes are sporting a nice veil of medium grained surface hoar.  This could be a player when it starts to snow again later this week.  A deeper surface hoar layer can be found down around 60 cm in depth.  This was a player in at least one close call last weekend.  There’s a stout rain crust near the ground that we’re calling the early November crust.  There are some facets below it too, but it’s unreactive at this time.  There is still a sharp transition in snow depth from treeline to below treeline making backcountry travel challenging under the 1300 m in elevation.  Remember, it’s still November.