Avalanche: Ben Lomond

Observer Name
Hardesty, Wewer
Observation Date
Thursday, January 12, 2017
Avalanche Date
Wednesday, January 11, 2017
Region
Ogden » Ben Lomond
Location Name or Route
Ogden Mountains
Elevation
7,500'
Trigger
Natural
Avalanche Type
Hard Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
3.5'
Width
150'
Comments

Avalanche cycle on many aspects below roughly 7500'...conservatively 7800' stepping down to Dec 15/16 rain crust. Crown depths ranged from 2.5-6' deep in heavily wind loaded areas with average at 3-3.5' deep. Aspects seemed to be more pronounced N>E>SE...with others likely as well.

Photo with Doug Wewer investigating the crown was at 6800' NNE.

2cm of 4F+ damp facets above the bullet proof 15cm+ rain crust that had been dormant until January 11th snow/wind. Sunday's rain crust buried 80cm down; guilty rain crust 135cm down in low elevation terrain.

Uncertain whether a skier/rider could trigger this layering in the coming days with the weakness buried deeply and under so much SWE. Unlikely but possible. "more research needed"

Only found one natural in the upper elevations - SE beneath Willard Peak a class 2. See photo.

Seems that much of the mid and upper elevation maritime instabilities will heal very quickly while the low elevations with suspect structure may need more investigation before "Open Season". Upper elevations has a graupel layer at 30 and 60cm down that will likely be revealed in tests but isolated at best in human triggering over the coming days. ECTN each.

No cracking/collapsing or signs of instability noted during the day/afternoon hours.