Professional Observation
Basic Information
Observation Details
Observation Date:
January 12, 2021Submitted:
January 13, 2021Observer:
WAC - Tom GuthrieZone or Region:
Northern WallowasLocation:
Fat RidgeSigns of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedSnow Stability
Stability Rating:
FairConfidence in Rating:
ModerateStability Trend:
WorseningBottom Line
I was skiing in the Northern Wallowas Tuesday and conditions were burly. It was snowing about an inch per hour while I was out and winds were strong out of the south.My snow pit data revealed a weak interface 12” down from the snow surface.My columns failed/propagated at this interface.I suspect this layer to be even more reactive today with the added weight of snow received yesterday afternoon,last night,and this morning.
Advanced Information
Weather Summary
Cloud Cover:
OvercastTemperature:
22Wind:
Strong , SSnow was falling at the rate of an inch an hour all morning and into the afternoon.Winds were strong out of the south.The combination of abundant snowfall and strong south winds was almost completely burying the skin track between runs.Expect to find deep and sensitive wind slabs on leeward facing slopes at and above treeline.
Snowpack Observations
I dug a snow pit at 7300’ on a northeast facing 30 degree slope at 12:30 yesterday afternoon.The snow at this location was 160cm deep and I dug to the ground.The air temp was 22 and conditions were blizzard like.My test column failed a foot down from the snow surface at the new snow/old snow interface that exists from the snow event that occurred Friday into Friday night.I did an Extended Column Test and got failure/propagation 30cm down (ECTP22 30cm down).I believe the thin weak layer is made up of facets that formed on the snow surface before the Friday snow event. Also worth mentioning is the SRC crust which is buried 80cm down at this location.It is becoming less defined but is still a potential problem in the snowpack.Below the SRC I found 2mm facets all the way to the ground.This thick and uncohesive layer of snow seems to be gaining strength but still lurks.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Storm Slab
|
|
Unknown |
Layer Depth/Date: 12” |
Although I did not travel above 7500’ I would expect there to be deep and sensitive wind slabs in the alpine and at ridge lines on leeward (NNW,N,NNE,NE,E) facing terrain.
Terrain Use
I found safe skiing on well anchored gladed terrain.
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