Avalanche: Hatcher Pass

Location: $1000 Run- NW Hatch Peak

Date:
Observer:
Route & General Observations

Road to the pass, then up to 4200′ and down via $1000 run.

Contact, Location & General Observations
Enter your contact information and a location for this observation. Note that you can submit anonymously, however if you would like to share your name with staff, but not the public, select No for "May we include your name in your observation"
Forecaster Comments

This avalanche failed on the persistent slab problem - unlikely to find, but possible. Fortunately, the skier and dog were able to get out uninjured. This avalanche was most likely triggered on the skin up, in a shallow spot. This is common with this type of problem and with such a large pre-existing condition as the buried near surface facets and depth hoar. With slabs this deep, you might get out to the middle of the slab before it breaks above you. Hard slabs are hard to predict. Be careful.

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 Trigger0
Avalanche Type Hard SlabAspect West Northwest
Elevation 4000ftSlope Angleunknown
Crown Depth 24inWidth 60ft
Vertical Run 500ft  
Avalanche Details

Solo skier and dog seen ascending NW aspect towards the ridge that leads to Hatch Peak mid-morning; crown observed as we traveled down $1000 run area at 1 PM.

The uptrack entered ~300' above the debris pile, with the slab breaking ~50' above the uptrack entrance. The slab ran to the ground. Tracks of both the dog and skier were observed leaving the debris pile, and the skier's truck was no longer in the lot by mid-afternoon. See photos below.

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

An additional fresh crown was seen to the Northeast of the motherlode parking lot by mid-afternoon, several hundred feet wide and running several hundred feet into alders. See photo below. Trigger wasn't obvious from a distance.

Numerous D1 loose snow avalanches were observed on a variety of aspects, often starting below cliff bands. One on skyscraper appeared to have stepped down and produced a micro slab.

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

Clear skies with a slight overcast haze by mid-afternoon. Occasional light winds from the NE, temps in the teens to low 20s.

Snow surface

At the parking lot, ski penetration of 8-12" and boot penetration nearly to the ground. Along the road up, wind affect became fairly widespread and apparent at 3500' and above, with thin wind slabs or thin wind crusts on most terrain. Along the ridge at the pass, lots of wind scouring from the recent storm, with rocks exposed.

Solar input didn't impact the surface, though we were generally on more northerly aspects.

Snowpack

Snowpit: 3200', NE aspect, 20 degree slope, HS=80. See full pit structure below.
Two primary layers of concern from the test:
40cm down, a thin layer of 4 finger facets had a fist -> 1 finger slab.
CT25 SC, ECTN23 down 40 cm in the 4 finger facets buried this past week.
70cm down well developed basal facets to the ground were observed.
CT23 SC, ECTX down 70cm in 4 finger basal facets.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.