Observation: Hatcher Pass

Location: Upper Willow Creek

Route & General Observations

Snowmachined over to Upper Willow Creek to dig on leeward aspects. Dug several pits between 4000’ and 4275’ on W, N, and NNE aspects.

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

Got a small, shallow whumph under a 20 cm supportable wind slab sitting on fist hard near surface facets.

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

25 degrees F in the shade, calm to light variable winds, clear skies. No new precipitation.

Snow surface

Tiny pockets of wind settled powder, huge expanses of breakable crust, and localized patches of slide for life supportable wind slab.


Extremely spatially variable due to recent wind transport.

Many locations have a stiff ~20 cm P+ wind slab sitting on either fist hard near surface facets or a thin layer of decomposing / broken precipitation particles.

In more sheltered areas, a faceted 1F to 4F slab can be found sitting on well developed, chained facets sitting above and below the melt freeze crust at the base of the snowpack.

In areas that have been previously wind loaded, a 1F+ to P hard slab can be found sitting directly on basal facets, with various thin layers of near surface facets sandwiched between hard slabs.

Pit results:

Pit 1: 4000’, W Aspect, 20 degree slope. HS = 80 - 105 cm. CT14RP, CT16RP, CT16BRK down 15-20 cm under a P hard wind slab. ECTX x 2. PST 35/100 END down 60 cm below melt freeze crust. PST 37/100 END down 47 cm above melt freeze crust.

Pit 2: See Snow Pilot profile below.

Pit 3: 4275’ , N Aspect, 20 degree slope. HS = 105 - 110 cm. CT23RP, CT24RP, CT24RP down 32 cm, P+ slab on 1F+ small facets. ECTX. No obvious melt freeze crust in this pit, a hard slab sits directly on basal facets.

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