N to NE aspects Mt. Tom
Tuesday, January 22, 2019 - 12:00pm
This report just in from individuals involved in Inyo SAR search and rescue campanion rescue training on Tuesday Jan 22:
-They observed one D2 Natural Avalanche occur on a N aspect of Mt Tom at ~8900'
-Observer also saw evidence of 2 natural slides in Elderberry Canyon on Mt Tom that afternoon that was not evident that morning on N and NE aspects between ~9500' and 10,000'. "Some dirt was visible in the track on one of the slides."
Lots of unknowns about these avalanches. Were these wind slabs triggered by active wind loading from the strong prevailing north winds that were forecasted for that day that the terrain caused to blow cross-slope? The reporting party did not say they noticed winds at these lower and mid elevations, however atleast in Mammoth, active cross-loading mid-slope below the crest was observed throughout the morning on northesterly facing slopes.
The big heavy dumping of snow ended the prior week on 1/17, and then the relatively modest snowfall occured during the night of 1/20.
Other speculated hypothesis: the modest (probably much less than a foot) snowfall on the night of 1/20 was blown into thicker sensitive windslabs, perhaps ontop of some small realtively newly formed surface facets (Or these areas slid during the big storm last week, and weak faceted snow was left behind in the start zones, and these newer windslabs were sitting on that?) If active wind-loading wasn't the trigger, could warming temperatures (and sunshine atleast on the East facing slide) be enough to be the trigger of this already sensitive structure?