Skyland - Patrol Ridge

Location Name: 
Skyland - Ptrol Ridge
Observation date: 
Monday, December 30, 2019 - 19:45

Is this an Avalanche Observation: 
Yes
Observation made by: Public

Tabs

Quick Observation

Dug two, north facing pits at 6,800 on Patrol Ridge deep in the Skyland region. HS 150-175cm. Both pits were ECTX. The top 100cm of snow slowly transitioned from very light pow down to 1F hardness. The bottom ~50 cm of the snowpack was weak and faceted. The stout early Decemeber crusts present in the Swan Range were not present here. I expected propogation with hard force on these basal facets, but both did not propogate. This was a cue to stay away from rocky, steep terrain with less snow. Across the valley, we saw two, small D1-1.5 avalanches below very rocky & steep west-facing cliffs. They looked wet and dirty like they resulted from warm rockfall. On an east facing slope on the very top of patrol ridge, we also saw a very small (D1), natural wind slab release that looked like it started from a small cornice fall. Things to note from the skin track:

  • Widespread surface hoar (see photo) on all aspects above 6,400'. It was well preserved and is worrysome for the upcoming storm. On N facing slopes, it grew on top of very low density snow, so there might not be a bed surface, BUT on S facing slopes, we found a melt-freeze sun crust underneath 2" of blower snow with some surface hoar on top. Could be a nasty sandwich with another slab. We skied the S facing breakable crust briefly between 6-6,500'. 
  • Winds were light out of the west on top of Patrol Ridge despite moderate winds back at the truck on Hwy 2. There's plenty of low-density snow availble for transport out there above 6,000'. 
  • We had sun in Skyland, despite the freezing rain soup back in the Flathead this evening.
  • Very low snowpack at Challenge Cabin quickly increased as we gained elevation. 
Snowpack, Avalanche, Weather Images: 
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Monday, December 30, 2019 - 12:00
Number of avalanches: 
1
Avalanche Type: 
Unknown
Failure Plane/Weak Layer: 
Unknown
Hide Trigger
Trigger: 
natural
Trigger Modifier: 
Cornice Fall Triggered
Hide Terrain
Aspect: 
East
Starting Elevation: 
above-treeline
Hide Size
Destructive Size: 
D1 Relatively harmless to people.
Relative Size: 
R1 Very Small
Avalanche Location: