24-25

Buried layers of surface hoar often show up a stripe in a snowpit wall (other things such a thin melt-freeze crust can look similar but feel much differently). A snowmobiler-triggered avalanche in Sunlight Basin broke on this weak layer of feathery surface hoar. Photo: GNFAC

Southern Madison, 2025-02-13

We rode into the Taylor Fork on Feb 13, We saw four persistent slab avalanches that likely broke last weekend or at the beginning of the week. All appeared to be snowmobiler-triggered R1-2, D1.5-2 avalanches at broke of the January layer of near-surface facets and surface hoar. Photo: GNFAC

Southern Madison, 2025-02-13

Wind Slab Avalanche in Hyalite

NORTHERN GALLATIN RANGE
Northern Gallatin
Code
SS-N-R1-D1
Elevation
7500
Aspect
W
Latitude
45.44150
Longitude
-110.95400
Notes

Climbed in the Mummy II area in Hyalite today. West facing ~7,500'. Lots of spindrift coming down onto the climbs in the area and we noticed lots of snow blowing around up high. No snow fell while we were there but our trail in was almost fully filled in and covered with a few inches to a couple feet of wind slab on the way out. Saw a small natural slide that started at the bottom of Cyptorchid. Crown was 10' wide and 8-18" deep, it ran 150' down a very shallow slope and covered the climbers trail. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1
Problem Type
Wind-Drifted Snow
Slab Thickness
12.0 inches
Vertical Fall
150ft
Slab Width
10.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year