Avalanche: Girdwood

Location: Crow Creek

Date:
Observer:
Route & General Observations

Crow Creek area up to 4000′

Avalanche Details
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Trigger NaturalRemote Trigger Unknown
Avalanche Type Soft SlabAspect South Southeast
Elevation 3500ftSlope Angleunknown
Crown Depth 12inWidthunknown
Vertical Rununknown  
Avalanche Details

We saw two recent avalanche crowns that were triggered from wet loose activity on a Southeast slope within the first half of the day.
We dug many hand pits at the elevation of the crowns (albeit a different aspect) and never found a persistent weak layer (only buried stellars). We were finding firm surfaces underneath the new snow so we are thinking the new snow was becoming more cohesive -slab like- under the influence of the now strong spring sun.
These were about 50-75' wide and sent debris 500' down. The attached pin is the approximate location for these avalanches.

We also saw an older but larger looking avalanche on the WNW face of Raggedtop. The crown had started to fill in but it appeared to be 900' wide.

Also, lots of sun-induced loose activity on steep southerly slopes.

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

Solar-induced recent activity.

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

Blue Skies and strong sun!
Down-sloping winds, otherwise light winds from Northeast at our high point.
Quite cold in shade.

Snow surface

New snow becoming moist on solar slopes, forming a sun crust once the sun rolled over to a different aspect.
The new snow was quite low density on non solar slopes. It drifted to various depths but typically around 20cm.

Snowpack

We dug many, many handpits through out the day without too much concerning results. Each one would shear on buried stellars, but on slopes without solar warming, the new snow was hardly behaving like a slab. We did not identify any buried surface hoar.
We suspect the slab avalanche reported here was due to the new snow gaining cohesion and turning into a slab, then sliding on the firm underlying surfaces with the once triggered by the wet loose activity. See photos

Photos & Video
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