| Recent Avalanches? | No |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | No |
Observation: Summit
Location: Manitoba
Manitoba to 3600′
Obvious signs of instability
Observer Comments
Two whumphs near 2000' in elevation... One large, extending 50+ yards with a visually noticeable deformation of the snowpack.
Weather
Broken skies trying real hard to be overcast... but we got moments of sun!
Temps around 20, generally calm with occasional light south wind above 3000'
Snow surface
Ski penetration of 3-6" below 2500', decreasing to 1-4" above until 3600'. Boot penetration much deeper along the entire route, 14" at 3100' and 18" at 2050' pit locations. Winds from yesterday above 3000' left an easily broken thin crust over the newer soft snow on wind prone features/ridgeline.
Snowpack
We dug twice, with the following results (see structure in photos below):
Pit #1: 2050', NE aspect, HS=95cm, 18 degree slope
CT 19 SC x2 & ECTP 23 down 45cm, failing in 2mm chained facets just below the very thin remnants of the Halloween crust - see photo and video below. This crust is much thinner in Summit versus Turnagain at comparable elevations.
Pit #2: 3100', W aspect, HS=165cm, 20 degree slope
Height of snow 3000' - 3100' was generally 160cm, with occasional depths of 120-200cm due to prior wind transport.
Two visible layers of buried surface hoar in the pit, but only the bottom layer failed in tests.
CT 26, 27 SP & ECTP on overdrive (45+ taps) down 65cm on 4-8mm buried surface hoar. This surface hoar sat on 4 finger .5mm facets.
Pit #1 described above. Ski pole probing revealed similar structure at this elevation band, including where we experienced the whumphs.
Chained facets through the scope - AJB photo
Chained facets - the weak layer in the pit above - seen hanging down below the Halloween crust
Pit #2 described above.
Fairly recent glide crack opening up on a SW aspect of Manitoba up Juneau Creek valley, at ~2700' in elevation
Sky cover for much of the day.