18-19

On Saturday (3/9) skiers observed multiple large natural avalanche crowns near Wilson Peak and Dudley creek in the northern Madison Range. They appeared to break on weak layers near the bottom of the snowpack. Photo: A. Pohl

Northern Madison, 2019-03-10

Old crowns near Mt. Wilson/Dudley

Dudley Creek
Northern Madison
Code
HS-R3-D2.5-O
Elevation
9500
Aspect
E
Aspect Range
SE-E-NE
Latitude
45.32390
Longitude
-111.32200
Notes

From e-mail: "The deep slab on the s face of Wilson was not an isolated incident. We observed a huge one on the east face of Wilson, in addition to numerous others in the head of both Dudley and deer, ranging from s/se to due north, all that looked to have gone sometime in the last few days."

Multiple Avalanches
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

On Saturday (3/9) skiers observed multiple large natural avalanche crowns near Wilson Peak and Dudley creek in the northern Madison Range. They appeared to break on weak layers near the bottom of the snowpack. Photo: A. Pohl

Northern Madison, 2019-03-10

Cracking and collapsing Buck Ridge

Buck Ridge
Northern Madison
Code
Latitude
45.19070
Longitude
-111.39400
Notes

Phone message: "On Buck Ridge in northern Madison Range... Experienced severe cracking then dug a snowpit in the second Yellow Mule. Yielded results of ECTP 24 Q1 on west aspect on layer 16" down on old snow/new snow interface. Total snow depth of 6 feet. 24 degree slope."

45.19073, -111.39432

Number of slides
1
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural avalanches in Hyalite

Hyalite Peak
Northern Gallatin
Code
HS-N-R2-D2-I
Elevation
10000
Aspect
N
Aspect Range
W, N, E
Latitude
45.38090
Longitude
-110.96100
Notes

A skier in Hyalite found a buried layer of near surface facets (NSF) that was reactive in stability tests and responsible for several avalanches in the Hyalite Peak area. He described this buried weak layer in an email: "It is currently down anywhere from 10-40 cms, above treeline, primarily on W-N-E aspects (not on S, there is a crust). I was hoping that yesterday’s warm temps may have helped, but things felt funky underfoot, and I got an ECTP13 (E aspect, 33 deg, 9900 ft), and bailed on my primary objective. I also observed several natural avalanches (HS-N-D2R2-I) that appeared to have failed on this layer a couple days ago, on Wind loaded N aspects above 10k. Besides this, there were no other signs of instability, no shooting cracks etc." 

Number of slides
1
Number caught
0
Number buried
0
Number killed
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year