Observation: Summit

Location: Colorado

Date:
Observer:
Route & General Observations

Trending north from the near the cabins up to 2650′ on east facing ridge between avalanche paths, dug at pit at 2400′ on south facing slope on the way. Descended to around 1600′ and traversed around towards the north side. Ascended to 2300′ dug a pit on NE aspect, descended and then traversed back to east facing terrain and skied back to near the cabins.  The alpine terrain is significantly wind affected. Lots of scouring, cross-loading and sastrugi.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?No
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?No
Observer Comments

Two whumpfs on a wind affected slope at 1900'. One was very large.
Recent avalanches on Tenderfoot , Hale-Bop, Tri-tip and Summit Peak

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.
Weather

Clear and sunny
Temperatures in the teens to mid 20°Fs
Light NW winds

Snow surface

3-5" of soft settled snow. Surface snow is faceting
Lots of variable wind effect from thin wind skin to breakable wind crust/small slab to hard sastrugi in the Alpine

Snowpack

Easy to find developed small facets under the recent settled snow or wind affected surfaced with hand pits and associated with a sun crust on southerly slopes

We dug at 2400' on a south aspect, 30° slope, HS: 150cm dug to the ground. There is a 2 cm sun crust 15 cm down with small facets above and below. The 1-2mm facets below are chained and striated. CT5 above crust, CT7 below the crust, ECTP2 above the crust. There is a very thin decomposing crust with facets down 30 cm, CT13. ECTN12. 12.1 melt-freeze crust is down 90 cm with facets below. No test results with associated with this layer. Basal facets are moist and rounding. The surface snow was just starting to heat up and become more cohesive as we were digging.

We dug at 2300 on NE aspect on a 23° slope. HS: 130. We dug to the ground. Surface snow is faceted but 15cm down there was a more pronounced layer (5cm thick) of small chained facets, CT12 ECTN13. 35 cm down there is another thin layer of facets, CT26 ECTN25. This lower failure was more planer or zippy - PW! Basal facets were again moist and rounding.

Photos & Video
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