We did a profile and some stability testing at the flank of an avalanche that was human triggered on Sunday 3/19 on a NW aspect at 4000'. The avalanche was approximately 150' wide by 200' long and 4 inches to 2 feet thick at the crown. Debris was pencil hard with blocks ranging from 4 inches to 12 inches thick and approximately 4 to 5 ft deep. Most of the crown was already filled back in from wind over the past 24-48 hours. HS at the flank was deeper than 300cm from continuous wind loading. The avalanche failed on a smooth, firm crust.
Observation: Hatcher Pass
Location: Eldorado Bowl/Skyscraper and Bennets ridge/$1000 run
Toured up Eldorado Bowl to the top of Skyscraper Peak to assess stability and riding conditions on all aspects. Strong ESE winds gusting up to 40+mph were actively transporting faceted snow onto leeward aspects. Cooler temps over the past few days have slightly faceted some snow surfaces and improved the quality from very poor to fair! We observed a large human triggered wind slab on a NW aspect on upper $1000 run that was triggered on Sunday. No cracking, collapsing, or recent avalanches observed today.
Dot on the map is the location of the avalanche from Sunday. More details in obs.
Avalanche Details
Observer Comments
We did observe active wind loading throughout the entire day as sharp facets were being transported from E aspects and loading SW thru NW aspects. Little to no low density snow exists for transport after several days of wind.
We did not observe and recent avalanches, cracking or collapsing.
Weather
No new snow since 2/28.
E winds gusting 20-31 mph for 5 hours at IM 3550'.
E winds 15-21 mph, gusting 23-39 mph for 11 hours at 4500'. The most significant part of the day was descending Skyscraper ridge holding our hats from blowing off with one hand and navigating severe sandblasting on our faces as facets were being transported by the wind.
Temps hovered around 20degF at 4500'.
Snow surface
Variable snow surfaces include firm and breakable sun crust to eroded anti-tracks with stiff to breakable thin windslab to faceted pockets of low angle terrain. Conditions are great for training on Denali or honing in your technical skills.
Snowpack
See pit profile for Eldorado Bowl
Avalanche from Sunday on NW aspect, 4000' , upper $1000 run
150 feet wide by 200' long
Crown 4" to 2-3ft deep
Debris estimated at 4-5 feet deep
Failed on facets on smooth crust 30 cm deep
ECTX
CT17 PC 30cm down
3/22 Wind texture on 4068'
Hard avalanche debris 4" to 2' thick from Sundays avalanche
Perhaps the worst conditions ever on Skyscraper ridge with plumes and wind transport visible in the distance
Forecaster Tim Rogers assessing stability on the flank of Sundays avalanche on $1000 run
Human triggered wind slab from Sunday on NW aspect 4000' upper $1000 run
Digging into the flank of the avalanche
Wind slab from Sunday with crown blown in and smoth bed surface
Debris from human triggered wind slab from Sunday on NW aspect 4000' upper $1000 run
Human triggered wind slab from Sunday on NW aspect 4000' upper $1000 run
3/22 Extreme gusts transporting facets that felt like a sandblaster . 4800'
3/22 South face of Skyscraper 4000'. Sun crust with chained facets growing under it.
Eldorado -22-Mar