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Feb Facets Still Lurking Deep in the Snowpack with Corn Conditions on the Surface.

Location Name: Elephants Hump Region: Carson Pass Area Observation Date & Time: Wednesday, April 4, 2018 - 11:45
Location: 38.696950, -119.970090 See map: CalTopo	Is this an Avalanche Observation?: No Conditions Alerts: Persistent Problem Rapid or Prolonged Warming Rapid or Prolonged Warming›Strong Sunshine Rapid or Prolonged Warming›Warm Temperatures Terrain Alerts: Trigger Points Terrain Matches the Advisory

Observation made by: Forecaster

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Observation

Description of Snow, Weather, and Avalanche Conditions:

Snow surfaces softened by 11 am on NW-N-NE-E aspects in this area. 2 to 4 cm of soft wet corn snow existed on top of a supportable melt-freeze crust on these aspects by that time. Boot penetration was only about 3 to 5 cm on the northerly aspects and closer to 8 to 10 cm on the E aspects by noon.

Well below the surface the Feb. facet layer still existed on NW-N-NE aspects. Probing on these aspects revealed a softer layer buried between 130 to 150 cm below the surface. A full snowpit on a N aspect (see attached pit) showed this softer layer to be the Feb. facet layer. Observations and data indicated that the snow above this layer is very strong. Actually getting enough force through this strong upper 150 cm of snow would take a very large trigger, but tests did still indicate that if the Feb. facets do break fractures could travel through that layer.

Ankle deep boot penetration on an E aspect at 8000 ft. at 12:45 pm.

$Propogation saw test targetting the Feb facets (the layer my finger is pointing to). The test failed about 1/3 of the way through the column (where the saw is stuck into the block) indicating that fractures can propogate along the weak layer. (PST 50/150 END down 146cm)$

Propogation saw test targetting the Feb facets (the layer my finger is pointing to). The test failed about 1/3 of the way through the column (where the saw is stuck into the block) indicating that fractures can propogate along the weak layer. (PST 50/150 END down 146cm)

The Feb. facets that have rounded but still remain a loose layer buried deep in the snowpack.

Snowpit or crown profile photo or graph:

Snowpack Details

Total Snow Depth:

195cm

Persistent Weak Layers:

Buried

Terrain Details

Terrain: elevations:

Near Treeline

Below Treeline

Terrain: aspects:

Weather Details

Elevation of Observation:

7000 - 8000 ft.

Wind Speed:

Calm

Sky Cover:

Broken - Mostly Cloudy - more than 4/8 and less than 8/8

Air temperature:

Above Freezing

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Feb Facets Still Lurking Deep in the Snowpack with Corn Conditions on the Surface.

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Feb Facets Still Lurking Deep in the Snowpack with Corn Conditions on the Surface.

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