Observation: Summit

Location: Fresno to 3000'

Date:

January 15, 2020 3:45pm

Observer:

Aleph Johnston-Bloom Forecaster

Route & General Observations

Up through the east facing meadow to the ridge and up to 3000′. Surface conditions and snowpack structure inventory.

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?	Yes
Collapsing (Whumphing)?	No
Cracking (Shooting cracks)?	No

Observer Comments

Some recent natural avalanche activity from earlier in the week. Small wind slabs and loose snow avalanches. (See Road Ob). The skier triggered avalanche from January 4th on Fresno is also still visible from the road.

Weather & Snow Characteristics

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

Weather

Clear skies
Temperature was -9 at the truck @ 1100', single digits at ridgeline. Very pleasant in the sun!
Calm

Snow surface

Surface hoar 1cm to around 1600'. Then slightly rimed stellars in the meadow to 2400'. Soft faceted snow in protected terrain above and in exposed areas up to 3000' hard wind board, mini sastrugi (fairly soft) and dappled facets. Scoured back to melt-freeze crust in spots. (see photos)

Snowpack

Dug @ 4 elevations.
1400' East aspect: HS 30 cm/1'. Soft facet layers and 3 decomposing melt-freeze crusts. Easy to push pole to ground. Runnels from NYE storm still visible. Chained facets below NYE crust.

2100' East aspect: HS 95 cm/ 3': 15 cm of soft facets over very thin NYE crust with more facets below down to a very stout melt-freeze crust. No slab present in the pit. No stability tests done.

NYE crust disappears around 2500'.
2600', south aspect, 30° slope: HS 105 cm/ 3.5', snowpack is all faceted including decomposing melt-freeze crust near the ground. Dug two pits at this elevation and no results with compression tests. Again no slab in this pit.

3000' south east aspect, 25° slope: HS 85 cm/just under 3': wind crust over facets. Again most of the snowpack is faceted including a harder layer 30 cm down of older wind effected snow. At this interface we had CT 18, CT 14, ECTX.
We hunted around trying to find deep enough wind effected snow to be a wind slab. We found a lot of wind board that easily cracked as we crosse and there was facets underneath the wind effected snow but we couldn't find wind slab. However we also avoided getting onto large open wind loaded slopes. The natural wind slabs we observed didn't look very deep.
Faceted snow sluffed easily on small steep convexities on the way down.

Photos & Video

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