Observation: Public
Observation Details
Name:
Mark DempseyObservation Date:
December 9, 2021Submitted:
December 9, 2021Zone or Region:
Snoqualmie PassActivity:
XC Skiing/SnowshoeingLocation:
Snow Lake TrailObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Dry Loose (Sluff)Size:
Size 2: Could bury, injure, or kill a personElevation:
4200 ft elevation at the middleAspect:
SComments:
Via the standard summer route to Snow Lake, before the divide at 4200 feet, there was a dry sluff that measured approximately 30-40 feet wide with about 150-200 feet of travel. Observation was at roughly 11 am.Returning through the area on our descent (approximately noontime), we noted new activity as the same slide now measured an estimated 70-80 feet in width. Could not determine runout distance.
Signs of Unstable Snow
None reported
Observations
The above stated avalanche was on a south facing slope that was slightly convex, and at 40-45 degrees.
Also noted several small slides (10-15 feet wide with as much as 100ft vertical travel) likely resulting from trees unloading.
A very quick, non-scientific assessment of the snowpack at 4000 feet on a south facing slope revealed a wet base layer starting from the soil/rock base of about 6-7 inches depth. Fresh snow measured 12-14 inches, with a half inch crust layer separating it from the wet layer. An earlier test at 3300 feet revealed the same characteristics.
Attached image was of the previous (smaller) slide.
Media
