Public Observation #2023-1135

April 4, 2023 7:45 PM
Observation Date:
April 4, 2023
Zone or Region:
Central Cascades
Tam Rim
Did you trigger any avalanches? 
Was it intentional? 
Avalanche Type:
Cornice Break
D2: Could bury, injure, or kill a person
This was an intentional cornice cut above a steep and potentially loaded slope. It did trigger a small point release when the cornice impacted the slope below. The combination of the cornice debris and the sluff could have carried a skier over some rocky, exposed terrain if this were unintentional
None reported
We toured out along the Tam McArthur rim today (4 April) in hunt of some good turns given the forecast. My buddies and I started out conservatively, poking around for signs of wind loading and instability. While we did observe visual cues of windloading on lee aspects, tests found that the only instability was minor sluffing from the jelly roll to the playground. Given this, we stepped into some of the steeper terrain skiers left of the playground and cut a cornice to see how the snow below would behave; the cornice did trigger a relatively small point release, but we had confidence in the slope stability. The skiing quality on the northeast to northwest aspects was fantastic and there was only minor sluff from our turns. Of note- there are large cornices hanging over many sections of all the bowls. The weather conditions ranged from overcast to broken, sunny skies, air temp hovered around 25°F, and the wind was about 10mph at most when we were above treeline. We left as the sun was starting to affect the snow quality, not wanting to linger under any warming cornices. Attached is a photo illustrating the cornices along the ridge out to the proboscis