Avalanche: Moab

Observer Name
Trenbeath
Observation Date
Wednesday, December 26, 2018
Avalanche Date
Tuesday, December 25, 2018
Region
Moab
Location Name or Route
Upper Horse Creek
Elevation
11,700'
Aspect
North
Slope Angle
40°
Trigger
Natural
Avalanche Type
Soft Slab
Avalanche Problem
New Snow
Weak Layer
New Snow/Old Snow Interface
Depth
18"
Width
125'
Vertical
600'
Comments
Two adjacent avalanches occurred during the night of Dec 25, this report refers to slide A in the attached image. Avalanche initiated as a fresh wind drift at the ridge crest approximately 12" deep and 30' wide. As it moved down slope it triggered a wider, and deeper avalanche approximately 125' wide and 2' deep that appeared as if it stepped down into a persistent weak layer of facets around rocks. It was difficult to ascertain from our vantage point, and dangerously wind loaded slopes, in extreme terrain prevented closer examination from above.
Comments
On Thursday, Dec 27, I was able to investigate the crowns on these slides and determined that they only involved recent, wind drifted snow. This report has been updated to reflect weak layer as the new snow/old snow interface.
Coordinates