Avalanche: Turnagain

Location: Seattle Headwall

Date:
Observer:
Route & General Observations

Shallow slab avalanche triggered by a snowboarder on the Seattle Headwall today, Saturday April 9th, 2022. Photo and video passed to us by Graham Predeger who was in the area.

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 SnowboarderRemote Trigger Unknown
Avalanche Type Soft SlabAspect Northeast
Elevation 3400ftSlope Angleunknown
Crown Depth 10inWidth 80ft
Vertical Run 400ft  
Avalanche Details

Snowboarder triggered a slab avalanche between 8 and 12" deep and roughly 70-90 ft wide. Rider was able to ride off the moving slab and was not caught. It was reported as a D1.5 which means it was not quite large enough to bury a person as the debris was minimal. It was however, large enough that it could have knocked a person off their feet, but that did not happen in this case.

This is the same zone where there was another skier triggered slab slightly larger from 5 days prior (4.4.22). The weak layer in both avalanches is suspected to be the April Fools' Interface, which is a thin layer of facets and small buried surface hoar sitting on a thin crust that sits roughly a foot deep.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

No red flags were seen today, until this slab was triggered.

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

Sunny skies and light NW winds.
Temps were chilly and shady slopes stayed cool while the crusts on sunlit slopes slightly softened during the day.

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.