20-21

From email: "Extremely touchy snowpack in the pebble creek drainage [on 1/16/21]. Nearly constant collapsing and cracks were shooting very long distances. Snowpack was definitely sending a clear message!" Photo: J. Zimmerer

@0400

Look for a distinct stripe in the wall of your snowpit 0.5-1.5' beneath the snow surface to identify a buried layer of weak surface hoar. Photo: GNFAC

Extremely touchy snowpack in the pebble creek drainage. Nearly constant collapsing and cracks were shooting very long distances. Snowpack was definitely sending a clear message! Found much better stability on a southeast facing slope (9800’) above Cooke.

While skinning up the south shoulder of Scotch Bonnet, about half way (~10,000 ft.) shooting cracks occurred on convexities and were accompanied by whumpfing. While traversing a slope a crack shot perpendicular to the slope at a convexity about 60 ft. up and the whole slope collapsed. After this we immediately turned around taking the most conservative path. These conditions were not present lower down the slope and a snow pit showed no propagation with only a Q3 fracture on the recent layer of surface hoar. It seemed that the higher elevation and more southern aspect decreased the stability of the recent surface hoar layer. The surface hoar layer was not reactive on more westerly slopes.

Skied the northeast ridge off Mt. Blackmore on Saturday, 1/16. No obvious signs of instability on the ascent (no whumphing, collapsing, cracking), and no signs of recent natural avalanches. Dug a pit at 9565 ft., SE facing. CT yielded no results, also did an ECT which had no results (ECTX). There's an ice crust at about 21cm from the ground sitting over facets. While we didn't get any fractures, our column slid cleanly on the crust when we pulled it. We chose to ski low angle terrain- the snowpack is clearly weak and shallow, there was wind loading (you could see continued wind transport as the day went on), and the danger was considerable.