Observation: Hatcher Pass

Location: Lower Powder Pimple, SW face of Marmot

Route & General Observations

Toured up to Powder Pimple and SW face of Marmot to investigate snowpack structure and stability. We continue to observe trends with poor snowpack structure which is slow to improve because of lingering weak layers.

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

We observed less whumping today than we did a couple days ago. However, due to the unseasonably warm temps today which felt like April, the slab is not faceting out, is more cohesive than a few days ago (and sitting on 15cm+ weak facets), and all our instability tests were reactive.

The most recent avalanche observed was the D2 human trigger on the SW face of Marmot on 11/16. This avalanche is a prime example of how challenging it can be to choose safe terrain with the current avalanche paradigm. In the past week, a few avalanches were triggered after numerous skiers/riders were on slope. The consequences of getting injured , despite a shallow snowpack in some locations, are real because of rock hazards.
We did not observe any new avalanches today.

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

No new snow since 11/14
Calm to light winds most of the day, increasing into the teens by 2pm from the south
Temps were ridiculously warm for November. Typically we have huge parkas on and its 0 to -20 deg F with no direct sun after 2pm. Today felt like April.
Of particular note ** It did NOT freeze on top of Marmot 4500' or at IM 3550' for two nights in a row. It reached a high of 40deg F today at 4500'.

Snow surface

Graupel still exists on snow surfaces. Surface hoar melted from the sun and warm temps. Snow surfaces on southerly aspects were warm enough to make a snowball today but still cold and low density on northerly.


Lower Powder Pimple (off Sunnyside of Hatch)
E/SE 3000' 35deg slope
HS 65cm
ECTP12 @ ground
PST 20/100 end
PST 22/100 end
all tests failing on 2-2.5mm facets at/near ground

Marmot SW face- (Similar aspect to the human triggered avalanche on 11/16)
SW 3400' 22deg slope
HS 70cm
ECTPV @ ground (failed on isolation!)
PST 20/100 end
all tests failing on basal facets at/near ground

Photos & Video
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