January 29, 2016

Observations

Eagle River – South Fork – Rendezvous Ridge

Red flags (obvious signs of instability):

  • Recent D2 natural avalanche in French Bowl (presumed to have failed from 1/27/16 wind event on widespread buried surface hoar identified today and in 1/24/16 observations)

Weather:

  • Snow ending about 10am, mostly cloudy with some sunny breaks through the rest of the daylight hours
  • Temps in the upper teens to low twenties
  • Calm wind

Surface conditions:

  • Generally 3-14″ fresh, dry, and very fluffy snow increasing with elevation
  • Fresh, stiff (1F) wind slabs (up to 4′) in deposition areas and areas of exposed old, hard (P+) wind slab (mainly around channeled terrain like Hunter Pass)

Snowpack:

Areas with stiff wind slabs on the approach to North Bowl via Hunter Pass (notice snow texture):Hunter Pass wind slabs

Hunter Pass approach AvaTech Probe profile (GPS tag a bit too far E):Hunter Pass profile with map

North Bowl snowpit (3928′, NW 298*, 33* slope, 137cm HS, ECTP5 Q1-2 sudden planar at 111cm on 3-4mm BSH, 24cm new snow right-side up):north bowl pit bsh 2

North Bowl AvaTech Probe profile (note BSH layer at ~26cm as pictured above, GPS off to the S):North Bowl profile

French Bowl pit to assess buried surface hoar (BSH) identified in 1/24/16 observations (layer is clearly visible as most distinct, uniform line across back pit wall ~18″ from surface):North Bowl pit bsh 1

French Bowl snowpit test results raise further persistent slab concerns (3738′, NW 311*, 41* slope, 236cm HS, ECTP13 Q1 sudden planar at 190cm on BSH):French Bowl pit bsh

The suspect buried surface hoar:French Bowl surface hoar

French Bowl AvaTech Probe profile:French Bowl profile

 

 

 

 

 

 

 

 

 

 

 

Looking up French Bowl (snowpit just below the high point):Top of French Bowl

A look at conditions skinning up French Bowl:Sam skinning up French Bowl

Heading back along Rendezvous Ridge:Rendezvous Ridge

AvaTech Probe profile between Pk 3787 & 4205 along Rendezvous Ridge W aspect, ~3800′ (surface hoar layer presumably between 30-40cm):3787-4205 profile

 

 

 

 

 

 

 

 

 

 

 

 

 

Skinning back up to Rendezvous Ridge from the Ship Creek Valley (above snowpit dug near ridge above ski descent tracks):Sam skinning up Rendezvous

Rain crust beneath the 3+” of fresh, dry snow is stout below 2500′, thin between 2500-2900′, and nonexistent above ~2900′ (doesn’t significantly affect snow riding quality above 2500′):SoFo Ship Creek rain crust

Moist-wet snow exists beneath the rain crust, in some cases moisture has percolated down to the BSH layer.