Observation: Public
Observation Details
Name:
Enji CooperObservation Date:
March 11, 2021Submitted:
March 11, 2021Zone or Region:
Stevens PassActivity:
XC Skiing/SnowshoeingLocation:
Arrowhead Mountain (east ridge)Observed Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Wet LooseSize:
Size 2: Could bury, injure, or kill a personElevation:
Near treelineAspect:
EComments:
Noted recent avalanche debris along east ridge (exterior) of Jim Hill. Unfortunately I didn't properly capture the issue in picture form.Seemed to be in a historical slide path.
Signs of Unstable Snow
Observations
Only performed hand-shear tests today.
Didn't observe real proof of stability, but I didn't dig that deep into the snowpack to understand what all was going on. That being said, I applied force via the butt end of my trekking pole and it took approximately 4 Finger/Finger+ force before going through the upper layers to powder underneath.
My snowshoes with tails sank in <1" at higher/shaded elevations earlier on in the day, but sun exposed areas and areas exposed to higher temperatures definitely seemed to cause my snowshoes to sink in further (2"~4"). I was carrying a ~25lb loaded pack and was using my La Sportiva Nepal EVO GTXs (which are heavy/stiff mountaineering boots), so the weight and my force on the downhill might have influenced how much I sank into the snow.
Anecdotally, the rain crust in the rain shadows under the trees were holding up quite nicely below treeline, however, there didn't seem to be a great deal of consistency between the trees (it seemed to be storm snow).
Media
Advanced Observations
Observed Avalanche Problem #1:
CorniceComments:
Many cornices were overhanging on Arrowhead Mountain: we hopped over/around 20+ up the east [high] ridge.From Arrowhead Mountain summit:
* The eastern arm off of Jim Hill also had large notable cornices on the east/north aspects.
* The Chiwaukums had large cornices on east/north aspects.
The cornices seemed to be most present on eastern aspects.
Observed Avalanche Problem #2:
Wet LooseComments:
Noted small wet loose conditions later in the day (after 14:00), coming down the eastern ridge of Arrowhead Mountain, between 3.5k'~5.5k'.Most roller balls were limited in size (pebble), but a select few grew to fist size.