Professional Observation
Basic Information
Observation Details
Observation Date:
December 29, 2020Submitted:
December 29, 2020Observer:
TAC - Andy BondZone or Region:
Taos AreaLocation:
Natural and Skier Triggered Avalanches on North through East Aspects near and above treelineSigns of Unstable Snow
Recent Avalanches?
YesCracking?
WidespreadCollapsing?
IsolatedSnow Stability
Stability Rating:
Very PoorConfidence in Rating:
HighStability Trend:
ImprovingBottom Line
Several natural avalanches were observed today as well as intentional skier-triggered avalanches on smaller test slopes near and above treeline. Slopes less than 35 degrees that we stepped on we would get shooting cracks and collapsing. On steeper terrain, we would these slopes to avalanche. Avalanche activity today was confined to NW to SE aspects.
Media
Advanced Information
Weather Summary
Cloud Cover:
OvercastTemperature:
10 - 20Wind:
Light , WOvercast day, with orographic snow showers, not accumulating to much new snow during the day. Light west winds with not a lot of snow transporting. There is a lot of snow available for transport.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Comments | Photo |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Today |
No Name Peak N 12,400' |
D2 | SS | O-Old Snow | Unknown | N-Natural | Natural avalanche on Sin Nombre Peak. Was hard to make out the crown but ran well into the flats and likely started just below the rocks |
|
| 1 |
Near Treeline North Aspect N 11,700' |
D1 | SS | G-Ground | 1 - 2' |
AS-Skier c-Intentional |
Triggered this avalanche from where I'm standing approaching the small test slope |
|
|
| 1 | Today |
Steep trees above Williams Lake NE 11,500 |
D1 | SS | O-Old Snow | 6 - 12" | N-Natural | This natural avalanche propagated upwards of 200' way out of view of the photo. It appeared to fail on facets at the interface of the new snow. |
|
We observed many natural avalanches mainly above treeline on North and East aspects. These avalanches appeared to have run sometime early this morning possibly when we had 2" an hour precipitation rates between 7 - 8 AM. Things were touchy out there today and we triggered several avalanches on small test slopes. Slopes needed to be above 35 degrees.
Snowpack Observations
Didn't conduct any stability tests today as natural and skier-triggered avalanches were all we needed to know stability was not great today. Even taking a ski pole, it's easy to feel the fragile weak layers and overall poor snowpack structure. We were surprised at how soft the slabs were considering we had 90 mph winds overnight. Didn't make it to ridgelines proper but would expect to find more of a wind slab on the leeward side of ridgelines.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Many natural and skier triggered persistent slab avalanches on N through SE aspects near and above treeline. Below treeline we were not finding cohesive slabs able to propagate | |||
Storm Slab
|
|
We expected to find stiffer cohesive slabs with the strong SW winds yesterday but were finding soft slabs that were able to propagate failing on the old interface. Most of the avalanches we saw seemed to fail within the old snow but a couple did not. We called this wind slab in the forecast but it's acting more like a storm slab in that it's light powder. |
Below treeline the biggest hazard is loose snow avalanches that are able to entrain and gouge the weak faceted snow especially in steep terrain.
Terrain Use
Kept it mellow just getting on small test slopes, a pretty good likelihood that you'd trigger an avalanche on a slope steeper than 35 degrees today. Good skiing on wind-sheltered lower angle terrain!
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