Avalanche: Summit

Location: Summit Peak

Date:

February 27, 2022 1:00pm

Observer:

Johnston-Bloom / Thamm

Route & General Observations

Standard up track veering to ridge and northeast shoulder up to 2460′

Avalanche Details

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Trigger	Natural	Remote Trigger	Unknown
Avalanche Type	Unknown	Aspect	South Southwest
Elevation	unknown	Slope Angle	unknown
Crown Depth	unknown	Width	unknown
Vertical Run	unknown

Avalanche Details

Wind triggered slab on Butch, the shoulder of the Incredibowls.

Red Flags

Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.

Observer Comments

Avalanches that likely ran on Friday 2.25 on Butch, Tri-tip, Summit Peak path 1 on the east face, Summit Peak north side (adjacent to the ones in Moderow's ob from 2.19.22), and in the Slate creek drainage on Gilpatrick.
Small wet loose avalanches and roller balls observed in steep southerly terrain

Weather & Snow Characteristics

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

Weather

Broken skies with some periods of sunshine
Calm winds
Temps in the high 30°Fs at road level and mid 20°Fs in the alpine

Snow surface

1" melt freeze crust at road level, crust thickness decreased with elevation disappearing around 2200'.
Crust soften on the descent with solar warming
Wind effect in terrain above the hemlock band including variable wind crust and sastrugi
Old wind blown avalanche debris from previous cycle

Snowpack

We dug one pit at 2460' on a northeast aspect (see photo). HS: 130 cm, the New Years crust was 50 cm down and 5 cm thick, the top of the November facets was 70 cm down (2-3 mm) CT28 SC, ECTX, the Halloween Crust was 95 cm down and 25 cm thick, with 5 cm of moist basal facets below.
We did a lot of probing in this area. In some spots the New Years crust is really thin or non existent and boot pen goes into the facets. In others the New Years crust is stout and supportable. The structure with the well develop November facets (and the recent avalanches) is concerning. However, it also seems like triggering an avalanche where the New Years crust is thick is unlikely but if you hit a zone where you could impact the November facets and there was propagation it might result in a large avalanche.

Photos & Video

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