Public Observation #2021-461

December 12, 2021 10:53 PM
Observation Date:
December 12, 2021
Zone or Region:
Central Cascades
billion dollar butte
Did you see shooting cracks? 
Did you experience collapsing or whumpfing? 
Observed 15 plus big whomps today while touring around bachelor. Previously, before this big loading event, I had been touring on Tuesday 12/07. I toured up to 9500 feet in the sisters region. slopes below 7200 had melted extensively. Upon reaching roughly 7800 the snow got interesting. From a distance, it looked like temps rose and rain got high following the 12/06 weather event. But once on the snow, it was a series of weak surface sugary snow and crusts that made up the upper snowpack. I remember grinning at the bottom of the run about how pleasantly it skied, but also thinking the snowpack wasn't ready to handle more weight. Touring all around bachelor today and yesterday and found a crust/ sugar snow layer that was repeatedly failing around 7300 feet and above. our highpoint today was 8100 feet. Weather and concerns about snow lead us to not travel any higher. We heard way too many loud, loud whomps while touring around and several quick hand pits showed this crust/facet? combo below the new storm snow. I don't want to quite call these facets cause they are in the early stage and are quite moist in spots, but it is very weak sugary snow. We have been finding this problem above 7300 feet on shady near and above treeline slopes that held snow prior to the Monday 12/06 small loading event. This layer is worth watching.

In addition to suspected persistent weak layers, we also observed signs of dangerous wind slabs and storm slabs, although the latter problem did seem to be trending positively as the hours progressed into dusk today. Didn't see any natural slides today, but the terrain we were on didn't have too great of potential for producing avalanches, and limited visibility has kept us from observing the higher peaks and faces.
Sorry for the spelling grammar errors.