Observation: Public

Observation Details

Signs of Unstable Snow

Observations

Weather: S-1, light southerly winds, OVC skies, cool temps with a wind-chill but comfortable during ascent. Warm sticky snow below 4,500 in the afternoon.

Snowpack: S aspect, 5,600' (NTL) 25 degree slope, ridge line terrain, shovel tilt easy and planar down 12cm (Nov 21 crust interface), CTE (1) SP down 12cm- this decomposing facet crust interface slid on small facets ( 0.5- 1.0mm FCsf), CTH (26) SP down 75cm- Nov 17th interface, while this result was hard and sudden the sliding surface was non planar. Interesting result none the less. ECTX. Again during removal and inspection of the ECT column and during chimney excavation ("shovel shear") the same planar interface was revealed down approx. 60cm. Here we found small 0.5-1.0mm sintering rounding faceted crystals (FCxr).

Avy: None of our test slopes resulted in slab releases including stomping small cornices (up to 1 body size chunk) onto steep leeward terrain (45 degrees). However loose dry was running full slope length up to 600' vertical with small piles of debris. This was primarily NE @ 5,800' at ridge line.

Travel Conditions- In sheltered cool aspects good track setting and turns made travel easy. Where as in exposed or solar aspects new snow on crust made skinning a challenge especially when encountering the occasional rime and ice surface. Surprisingly we found few isolated moist windslabs under the new snow. Expecting more evidence after some strong winds the prior day. Of course filled in slopes were punctuctated with terrain traps of all shapes and sizes and shallow buried rocks that were glazed with ice or snow and difficult to see while descending. Our descents were generally NE-E- ESE, up to 5,900' (NTL), near ridge line on terrain up to 40 degrees.