Most of the avalanches triggered yesterday and the day before were in the new snow – sluffs and shallow new wind slabs up to a foot deep and 50’ wide or so. This type of avalanche is easily mitigated or avoided and is what I would term “Manageable”. I wouldn’t call them harmless, but – “more forgiving” unless you’re pushed into or through terrain traps. Avalanches of this type (northerly through easterly above 9400’) – most running on Saturday’s weak snow surface of either recrystallized faceted snow or surface hoar triggered by backcountry skiers included:
· Upper Days Fork (at least three) up to a foot deep and 30’ wide (1st pic - Mark White)
· Keyhole into Cardiff Fork – 8-10” deep and 20’ wide
· LCC UDOT Indicator Slope – 6-16” deep and 40’ wide
· West Bowl of Silver Fork – 3-12” deep and 50’ wide (2nd pic - Jake Hutchinson)
Others – the Outliers (the Low Probability – High Consequence situation we’ve had for more than a month) will kill you…or result in significant injuries or deep burial. The Black Sheep, or Black Swan – outside of our day to day pattern recognition. Three significant Black Swans over the past two days –
· A single explosive thrown in the uncompacted/unskiied terrain along the Pinecone ridge of the Park City Mountain Resort triggered an adjacent avalanche path 2-3’ deep and 275’ wide. It pulled out to near the ground, leaving a black hole in the intact snow where the charge detonated. (This mind you, a single 2 pounder surface shot). (PCMR photo, below)
· A snowmobiler in the Franklin Basin terrain (in the Logan forecast area just north of the Idaho border) unintentionally triggered a deep slab 3.5’ deep and 60’ wide on a steep east facing aspect at 9000’. You can watch the rider abandon his sled, grab a tree and hold on, the hard slab washing by into the flats. (Observation/video – Warning! PG rating for language – that is – an authentic video/not a scripted made for tv gig)
· Kobernik and Meisenheimer found a 1’ deep and 200’ wide hard slab triggered on Sunday by a snowmobiler in the Ant Knolls area of American Fork/above Midway. It was on a southeast facing slope at 9500’, collapsing a couple inch thick melt freeze crust in the process. (Kobernik photo below)
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