Bridger Range

Dry Loose Storm Slabs

Date
Activity
Skiing

Skied the north chutes above fairy lake around 8,400 ft. Found 8-12" of new snow, with the bottom 2" consisting of large graupel. In steep terrain our sluff entrained lots of snow making for some large debris piles. Overall the snow was generally well bonded.

Region
Bridger Range
Location (from list)
Fairy Lake
Observer Name
Spencer Lipsteuer

Broke a small wind slab on Sluice Box

Date
Activity
Skiing

A small wind slab broke as I was skiing down Sluice Box near the weather station on Bridger Ridge. Crown was about 8 feet wide and the slide path looked to be about 60 feet. I was out of its way and unharmed, gave me a pretty good scare though! 

Region
Bridger Range
Location (from list)
Bridger Bowl Weather Station - The Ridge
Observer Name
Karl

Storm snow avalanches on Throne

The Throne
Bridger Range
Code
AS
Elevation
8300
Aspect
N
Aspect Range
N, SE
Latitude
45.88220
Longitude
-110.95200
Notes

The skiing was good and non reactive on the main East face next to the skin track. The North gullies into Naya Nuki creek and the the lower/steeper gullies to the south were highly reactive and entraining lots of snow.

Number of slides
2
Number caught
0
Number buried
0
Trigger
Skier
Problem Type
New Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Small wind slabs in Bridgers, Ross Peak

Ross Peak
Bridger Range
Code
SS-AS-R1-D1-S
Elevation
8500
Aspect
NE
Latitude
45.85860
Longitude
-110.95600
Notes

Skied the Banana today with 8-12” of new snow that has mostly bonded. The snowpack below the new snow had froze over night and was well consolidated. 

Observed a layer of graupel (3-4mm grains) at the new/old interface on the NE ramp starting at 8600’ and clearing up after 8700’.  This layer created some reactivity in the storm snow.
Wind slabs <6” had formed on N and NE aspects. We had one small release in the bottom of the couloir measuring ~10x20’ and running ~50’.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
1
D size
1
Bed Surface
S - Avalanche released within new snow
Problem Type
Wind Slab
Slab Thickness
6.0 inches
Vertical Fall
50ft
Slab Width
15.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Good skiing, but...

Date
Activity
Skiing

The skiing was good and non reactive on the main East face next to the skin track. The North gullies into Naya Nuki creek and the the lower/steeper gullies to the south were highly reactive and entraining lots of snow.

Region
Bridger Range
Location (from list)
The Throne
Observer Name
Bob

Small wind slabs and good skiing

Date
Activity
Skiing

Skied the Banana today with 8-12” of new snow that has mostly bonded. The snowpack below the new snow had froze over night and was well consolidated. 

Observed a layer of graupel (3-4mm grains) at the new/old interface on the NE ramp starting at 8600’ and clearing up after 8700’.  This layer created some reactivity in the storm snow.
Wind slabs <6” had formed on N and NE aspects. We had one small release in the bottom of the couloir measuring ~10x20’ and running ~50’. 
 

Other than that, the skiing was amazing and manageable. 

Region
Bridger Range
Location (from list)
Ross Peak
Observer Name
Shep

Limited re-freeze in Southern Bridgers

Date
Activity
Skiing

We skied Saddle as early as we could after the lifts opened, but we were still a bit late, and/or there was limited overnight refreeze, I suspect more of the latter. Clear-ish skies overnight had me optimistic, but warms temps seem to have dominated below 9000 ft.

The first 100 vertical feet from the summit skied quite well where a thin melt-freeze crust was just starting to break down. Overcast skies and L-M winds likely limited warming. Below 9000 ft we poked around and found the top 15-20cm was moist and unsupportive on NE-SE aspects. We kicked off numerous roller balls but no actual loose wet avalanches. 

The best skiing was in previously skied areas, such as the guts of going home chute, or in-bounds.

Region
Bridger Range
Location (from list)
Saddle Peak
Observer Name
N. deLeeuw

Wet Loose Avalanches in Airplane Bowl

Fairy Lake
Bridger Range
Code
WL-N-R1-D1-I
Elevation
8500
Aspect Range
S-SE-E
Latitude
45.90430
Longitude
-110.95800
Notes

We rode up to Fairy Lake area today and quickly found out just how warm it has been in this area the last two days. At the trailhead at 10am temperatures were around 47 degrees. Last night, it did not freeze below 9000' and an isothermic snowpack now exists from the trailhead all the way to Fairy Lake and above, until you pop out into Airplane Bowl. When we returned to the trailhead around 2:30pm, it was 65 degrees at the truck. 

While higher elevation southerly and easterly snowpacks were warm and wet, free water was only moving through the upper few inches of the snowpack by 1pm. High elevation northerly aspects remained colder and more locked up than we expected given the ambient air temperature. Winds were light from the W and were doing little to keep surfaces cold.

There were a number of wet loose avalanches in Airplane Bowl when we were heading out around 2pm. All on E/S aspects near rocks or cliffs. Most were relatively small and had not entrained much snow from the surface or gouged deeper than a few inches. 

On the drive back to town, we noted 5 or so larger wet loose avalanches in Argentina Bowl, with a good number of smaller slides at different points along the ridge

Seeing as it is now the season for wet snow hazards, there are a few things that are critical to consider: aspect, elevation, and timing.

Timing your day to be off of steep slopes before melt water percolates too deep and destabilizes the slope is key, AND making sure to account for steep low-elevation slopes that you may have to pass through on your way back to the trailhead. If you start to sink in deeper than your ankles, or your sled track is digging into slush, that means it is time to either shift to colder aspects or head back to the trailhead. 

Our greatest concern with these wet loose avalanches is not so much their size, but their power to push you into terrain traps like cliffs, gullies, trees, or rocks. The two scenarios when we are most concerned about these avalanches are when new snow gets wet and sheds for the first time OR when there have been multiple days without a solid refreeze and melt-water percolates deep into the snowpack. 

 

Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
R size
1
D size
1
Bed Surface
I - Interface between new and old snow
Problem Type
Wet Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year