Observation: Girdwood

Location: Meadow run

Date:

February 10, 2020 9:50pm

Observer:

N. Pfeiffer / R. Van Luit Forecaster

Route & General Observations

On Feb. 6th a powder cloud was observed in the Surprise Bowl area of Goat mountain. My partner and I considered investigating the avalanche, but due to concerns within the snowpack and building northwesterly winds, we decided to remain out of the terrain trap drainage.
Instead, we ascended the Meadow run in hopes to get a view of the crown and flanks of the Surprise Bowl avalanche.

Avalanche Details

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Avalanche Details

We estimated that 6-10" of snow fell in the area since the powder cloud of this avalanche in Surprise bowl was observed on 2.6.2020.

Red Flags

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Observer Comments

The northwesterly winds were building so rapidly that we decided to return to the trailhead.

Weather & Snow Characteristics

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Weather

Sunny.
Winds - Calm in Treeline. At the beginning of the tour we watched intermittent gusts plume snow from a few peaks and ridges in the Alpine. By 1:00p, northwesterly winds were steady and moderate in the Alpine, sending plumes.
Temperatures ranged from teens to low 20's F.

Snow surface

6" of powder with hints of graupel in small depressions.

Snowpack

Meadow Run
South aspect

Testpit #1 at 2070' (See snowpilot image for details)

Testpit #2 at 2040'
HS 145cm
31 degree slope
Ski/Boot Pen. 15cm (6") / 80cm (31")
ECTP26SP ↓95cm (X2) on 2-3mm chained facets beneath a crust (Dec. 9)
We found the NYE crust in this pit ↓50cm

Photos & Video

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The powder cloud from this avalanche was observed on 2.6.20 from Crow Creek. The arrows are pointing to the crown and flanks.

Intermittent northwesterly winds in the morning in the Crow Ck drainage. 2.10.2020 . Photo: CNFAIC Archive

The northwesterly winds built from intermittent to steady, leading us to retreat by 1pm.

We saw small pools of graupel in most depressions throughout the tour.

Testpit #2 (in description) propagated across the column and slid into the pit. ECTP26SP ↓95cm (X2) on 2-3mm chained facets beneath a crust (Dec. 9)

Image from testpit #2. These 2-3mm chained facets ↓95cm were the weak layer below the Dec. 9 crust

Hardness profile from testpit #2, similar in structure to testpit #1 documented in snowpilot image

Testpit #1 at 2070'