Gunnison

Triggering an avalanche is unlikely, but not impossible today.  An observation of collapsing snow and shooting cracks on a north-facing slope yesterday highlights that isolated instabilities still exist.  You can reliably avoid the lingering threat of a slab breaking on old snow near the ground by riding on east, south, or west aspects.  

We have gone over a week without reported signs of instability or slab avalanche activity.  But yesterday, our field team observed shooting cracks and collapses on a steep, northerly facing slope harboring old, faceted snow leftover from October storms.  While slopes like this are rare to find, the observation highlights how the ingredients for an avalanche still exist.   Those slopes are well defined:  high elevation, northerly terrain - terrain where our early season weak layers survived the sun and warm temperatures of early November before a series of storms and wind events in November buried them with slabbier snow.  On those northerly aspects near and above treeline,  be especially wary of terrain with smooth underlying ground cover where the weak layer is continuous: think grassy slopes or slopes with smooth shale instead of chunky talus.   Strong northwest winds last weekend stripped away a lot of the snow on suspect aspects, further reducing the distribution of problematic slopes.  The terrain features that survived the wind scouring and hold deeper or crossloaded deposits are where you might still find trouble.    You can make a bomb-proof route plan by choosing aspects that face east or south or west where weak layers don’t exist.  

Dry weather today will give way to snowy conditions tomorrow.  The avalanche danger will increase by Monday evening as snowfall and windloading develop storm instabilities and add weight to our existing persistent slab structure.  

Mark your calendars! December 4th is CBAC's Virtual Avalanche Awareness Night.  A party and educational event, the likes of which you've never seen before.