CNFAIC LogoCNFAIC Logo

Observations

Region: Hatcher Pass
Location: Marmot SW face
Observer:
Date:

Route & General Observations

Mid-elevations, all aspects, highly discontinuous and shallow snowpack (HS 25cm-40cm), heavily scoured and loaded in isolated to specific areas, localized whumphing and shooting cracks. Persistent slab sensitivity stubborn to touchy.

Upper elevations, all aspects, in specific locations where winds deposited more continuous, thicker and cohesive hard slabs the persistent slab avalanche problem was more significant, up to 85cm (3 feet deep), averaging 45cm (1.5 feet deep). Persistent slab sensitivity touchy. Human triggered avalanches likely, remotely triggered avalanches possible.

Old raised tracks on some steep upper elevation slopes, sastrugi, supportable and breakable crusts and old wind slabs. Slabs begining to facet out, areas without cohesive slab are pure facets.

The gem for skiers or boarders would be finding a zone that lacks the slab and skiing pure square powder. We did not find it.

 

 

Avalanche Details

Avalanche details

Trigger SkierAvalanche Type Hard SlabAspect South Southwest
Elevation 3900ftSlope Angle 40degCrown Depth3ft
Width 60ftLength 900ft  

Observer Comments

avg crown height 1.5 feet;
touchy trigger from low angle (30 deg) ridgeline

Red Flags

Obvious signs of instability

Recent Avalanches?YesCollapsing (Whumphing)?YesCracking (Shooting cracks)?Yes

Observer Comments

Cracking an whumphing abundant. Localized up to 15 meters, depth 25 to 40 cm. Mod strength, Poor structure, high energy.
Recent avalanche same aspect and elevation, winds Jan 5?

Weather

Weather

Ta= -9.2C, Ts= -7C @ 3400', Calm, surface snow NSF 0.5

Snow Characteristics

Snow surface

NSF, wind board 2-6" thick, wind exposed xtra fragile faceted crust

Snowpack

Old wind slab over weak mid-pack over extra weak depth hoar

Photos & Video

Photos



USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments or questions regarding CNFAIC operations or winter recreation management, please email staff@chugachavalanche.org
© 2017 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC
Donate
If you think a public avalanche
center is important then we urge
you to become a member & donate.


PickClickGive