Avalanche: Hatcher Pass

Location: Sunnyside of Hatch

Date:
Observer:
Route & General Observations

Standard up track to the sunnyside of Hatch (up Powder Powder Pimple and then along the ridge).

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger SkierRemote Trigger No
Avalanche Type Wet Loose SnowAspect Southeast
Elevation 3500ftSlope Angle 40deg
Crown Depth2ftWidth 40ft
Vertical Run 1500ft  
Near Miss / Accident Details
Avalanche Details

The avalanche was skier-triggered. The trigger point appeared at a shallow patch of snow about mid-run right next to a rock band in a steeper (~40 degrees) part of the run.

Events of the day

Before tour: We checked weather stations and noticed the Marmot weather station was staying consistently below freezing at night over the last few days. We had been skiing regularly after work (and had done the same tour on Sunday). We noticed the natural avalanches on similar aspects at similar elevation bands that ran to the ground on the drive-in. However, we thought that since we were timing our tour later in the evening and the naturals looked small, we thought would be okay. We also made a plan to stick to higher elevations because the lower-elevation weather stations had above-freezing temps for the last couple days.

During tour: We ascended on an E/NE facing slope. On that slope, the snow was supportable and we ascending on an icy frozen skin track. Along the ridge had colder temperatures and water was not moving freely through the snowpack where we dropped in. 1st skier skied the line and was a little spooked about midway through the run and traversed skiers right to an aspect more east-facing in the shade in more supportable snow. 2nd skier skied halfway through the run and triggered the wet loose avalanche in shallower isothermal snow near a rock band in steeper terrain. The avalanche entrained a lot of snow to the ground and ran to the creek. The debris pile was "two short school buses" wide with "microwave to mini-fridge sized balls of snow" After triggering the avalanche, 2nd skier was spooked, and traversed to the skier's right to more supportable snow (same line that skier I skied). 3rd skier was spooked and did not ski the run. They returned to the skin track and descended on the skin track in the shade. Skier 1 and 2 met skier 3 at the base of Powder Pimple. We debrief our decision-making back at the car.

After the tour: We debriefed the near-miss to learn from our mistakes.

These are the human factor components we came up with:

Familiarity: We have skied that run many times before and had skied it earlier in the week and to us, that run feels "safe"

Acceptance: We wanted everyone to have a good tour and have a good time skiing. One of the group members expressed excitement for corn, and the snow conditions on the south appeared to ski nicer than the ski conditions on the north, so we made a decision based on best ski quality rather than avalanche hazard.

Complacency: We had not had a near miss in our friend group in a long time so we collectively have been a bit complacent. Lastly, we all kind of have "April brain" or "spring fever" also known as manic sunshine energy after a long dark winter. We have excitement to do things in the sunshine later in the day (and this is not always accompanied by thoughtful intentional decision-making).

Other thoughts:

Radios: Radios make communication so much easier, we don't always bring them, but after today we will always bring them!

Terrain management: Terrain management and general safe travel protocols saved us (moving to safe zones, we had eyes on our partners for most of the run, and we had the ability to read terrain and made decisions around where to move and how to manage it)

Spring shed cycle: The spring shed cycle is pretty late in Southcentral this year and a lot of Southcentral is not going to have avalanche forecasting for when it happens.

Rescue events

No one was caught or carried

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

Saw multiple (~6) D1 to D1.5 natural point-release wet avalanches that ran to the ground and appeared to start at the shallow snow around rock bands on the south aspect of Sky Scraper and the south aspect next to Baby Ruth. On the drive in we noticed a larger (~D2) on a south-facing aspect next to Divide Ridge (Idaho Peak).

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

Mostly blue skies, temps in the 30s and 40s, no wind

Snow surface

We ascended on an E/NE-facing slope. On that slope, the snow was supportable, and a frozen icy skin track. The snow at higher elevations was also supportable so when we were along the ridge we felt excited about skiing corn. Along the ridge had colder temperatures and water was not moving freely through the snowpack where we dropped in. That being said, about halfway through our run was a different story. We would repeatedly sink to the base of the snowpack on skis in the snow and had to move to a more shaded spot halfway through our run.

Snowpack

Isothermal- where we triggered the avalanche there were large melt freeze grains and water was moving freely through the snowpack

Photos & Video
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