19-20

From (5/17/20): "...WS - ASu - R3 - D2 - I SE face of Middle Basin Peak starting at 10,000' Estimated SZ of 30° Slab depth of about 8". We were out too late in the day and chose to ignore a number of observational warnings. We were lucky and remotely triggered the avalanche below us."

Northern Madison, 2020-05-21

Very large wet avalanche at the YC

Yellowstone Club
Northern Madison
Code
WS-NC-R4-D3.5-O
Elevation
9840
Aspect
NE
Latitude
45.23110
Longitude
-111.44100
Notes

Doug McCabe left a message:

A very large wet slab avalanche released on an east aspect of the YC. It was not human triggered. This is the biggest slide he has seen on the shoulder with an estimated 6-8' deep crown. The slide hit a tower. R4/D3.5.

From e- mail (5/20): "Got a better look today. WS-NC-R4.5-D3.5. Trigger looked to be from a cornice fall. The crown was measured at 1800’ in length and ran full path, 950’. NE facing slope at 9840’. The crown was mostly between 6-8’, but ranged from 4’ to 9’. The cornice fall occurred on a shallower section of the snowpack."

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Cornice fall
R size
4
D size
3.5
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness
72.0 inches
Vertical Fall
950ft
Slab Width
1800.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year