Avalanche: Hatcher Pass

Location: Marmot SW ridge to Mid-rib

Date:
Observer:
Barker Kayes Forecaster
Route & General Observations

Toured up Marmot in super flat light to check out the new snow/wind effect on the snowpack. Toured up the standard SW ridge and down the mid-rib. Triggered two small slabs that were freshly loaded on leeward aspects at upper elevation. Remotely triggered a D1.5 slab from the ridge, likely near the Death Gully.

 

 

 

 

 

Avalanche Details
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Trigger SkierRemote Trigger Yes
Avalanche Type Soft SlabAspect West
Elevation 3800ftSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Run 1000ft  
Avalanche Details

#1 Human triggered cornice triggered a small (10'x10') slab that failed on NSF sitting on the 2/27 Drizzle crust. W aspect 4000'
#2 Human triggered small slab 4-12" deep, 20' wide by 40' long. W aspect 3700'
#3 Remotely triggered avalanche D1.5 . Exact aspect and elevation unknown due to flat light and no visibility. Estimated @ west aspect 4000'.
All soft slabs from freshly loaded persistent slabs from 3/10.

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)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

5-7" of new snow combined with .7" SWE and SE 15-19 mph G 22-30 for 4 hours contributed to building fresh slabs that overloaded weak persistent grains sitting on the Drizzle crust.
Observed small shooting cracks up to 10 ft long, isolated whumping, triggered two small avalanches and remotely triggered a D1.5 slab avalanche.

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

5-7" new snow 3/10
SE 15-19 mph G 22-30 for 4 hours
Temps:
18 deg at 4500' @ 1300
23 deg at 3550' @ 1300

Snow surface

New dense snow sitting on buried NSF (near surface facets) on the 2/26-27 Drizzle crust. The drizzle crust is acting as the bed surface.

Snowpack

See pit pic.

Photos & Video
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Deris from human triggered small slab 20'x40' and 4-12" deep . W aspect 3700' 3/10  

Debris from D1.5 remotely triggered avalanche. Exact location of trigger unknown due to poor vis. Best guess is 4000' W aspect.  

Crown depth approx 4" . Notice the slab failed on NSF on the Drizzle Crust. Although the drizzle crust can be crumbled in your hand with moderate force, it is acting as the bed surface.  

Marmot mid rib Pit  

Location
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