21-22

Photo

Date
Activity
Skiing
Region
Bridger Range
Location (from list)
Saddle Peak
Observer Name
John E Milich

Natural Avalanches on Saddle Peak

Saddle Peak
Bridger Range
Code
N-R2-D2
Elevation
8950
Aspect
E
Latitude
45.79430
Longitude
-110.93600
Notes

We observed a natural avalanche on Saddle Peak on our drive home today. The Bridger Range received 7" of heavy snow equal to 1" of snow water equivalent in the last 24 hours. During the day we saw heavy wind-loading occurring on the high peaks of the range including Saddle. 

Bridger Bowl Ski Patrol noted a few slides in the morning (one cornice triggered), estimated 2' deep.

 "...cornice triggered slide on saddle today. Broke a couple of feet deep, and I couldn’t get too close to the crown but it seemed to have initially broken in the new snow and then stepped down to a PWL below the recent crust...propagated maybe 130ft wide and ran all the way over the saddle cliff to the flats."

Number caught
0
Number buried
0
Trigger
Natural trigger
R size
2
D size
2
Problem Type
Wind-Drifted Snow
Vertical Fall
1200ft
Slab Width
150.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Lick Creek

Date
Activity
Skiing

Did a quick tour up Lick Creek this afternoon. Broken clouds, light to moderate wind near the summit, with intermittent snow showers. About 8-10" of fresh, fairly high density snow on the east side of the summit. Significantly less on the west facing slope.

I did a few hand pits on the east facing slope as I travelled back up to the top to explore the old/new interface. I suspect last night's storm started as rain below about 7800 ft, as there was a thin crust under the new snow below this elevation that I did not observe at the top. It was easy to hand shear the new snow off this layer where it existed.

Above about 7800 feet, I did not see this thin crust layer. The new snow seemed right side up and better bonded to the old surface. 

Region
Northern Gallatin
Location (from list)
Lick Creek
Observer Name
Chris Pierce

GNFAC Avalanche Forecast for Wed Mar 16, 2022

Snowpack and Avalanche Discussion

<p>Chances of triggering an avalanche in the Bridger Range just went up. The 6” of new snow is very dense and heavy and measures .9-1” of snow water equivalent (<a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314…;). One inch of water weight falling in 16 hours is a rapid and heavy load and the snowpack needs time to adjust. The weight of the new snow is causing the elevated danger.&nbsp; There are weak layers of facets in the upper 2 feet of the snowpack that will avalanche under this load. West wind is strong enough to make drifts which could be easily triggered today. Even without a wind load, be on the lookout for shooting cracks or collapses (whumpfs). These are signs of instability. Today’s avalanche danger is elevated to CONSIDERABLE since it’s likely to trigger avalanches.</p>

<p>The mountains around Cooke City received 5” of new snow measuring .5” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314…;. This totals 18+” of new snow since Saturday. Alex spent the last few days there and saw avalanches as recently as Monday. Yesterday he skied around and had an isolated collapse and cracking wind drifts in the trees. A weak layer 1-2 feet under the surface is unstable and could avalanche, especially on slopes with thicker wind drifts. His 2 videos (<a href="https://youtu.be/beIj2Ar5_yk"><strong><u>Saturday</u></strong></a&gt;, <a href="https://youtu.be/f6wLR3tLNa8"><strong><u>Monday</u></strong></a&gt;) show the exact nature of the instability that has caused <a href="https://www.mtavalanche.com/avalanche-activity"><strong><u>over a dozen slides since Saturday</u></strong></a>. Triggering avalanches remains possible with the new snow and the danger is rated MODERATE on all slopes.</p>

<p>The mountains south of Bozeman to Big Sky and West Yellowstone received 3-5” of new snow (.3-.5” <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314…;) and triggering avalanches is a strong possibility. Yesterday Dave investigated a skier triggered avalanche from Sunday in the backcountry outside Big Sky Ski Area (<a href="https://youtu.be/f6wLR3tLNa8"><strong><u>video</u></strong></a&gt;). A dense slab broke on weak snow that was still showing signs of instability in his test (ECTP 13). Even more impressive than a poor stability test was a large natural avalanche on Cedar Mountain that was witnessed a few hours previous (<a href="https://www.mtavalanche.com/images/22/large-natural-avalanche-cedar-mou…;).</p>

<p>Yesterday, Ian and I skied into Mt Blackmore to look at the skier triggered slide from Monday (<a href="https://youtu.be/LlQ7_KU0lCI"><strong><u>video</u></strong></a&gt;). The snowpack structure is similar throughout southwest Montana: a dense slab of snow is atop a weak layer of facets buried 1-2 feet deep. Every time it snows, even a few inches, this layer becomes unstable on some slopes and folks trigger avalanches. The exact location of these unstable slopes require you to dig and test the snowpack. There’s no easy way to be safe in avalanche terrain without doing homework. Dave found this instability in Beehive on Sunday (“<a href="https://youtu.be/NTjHmlc7JHg"><strong><u>Why We Dig Snowpits” video</u></strong></a>) and snowmobilers triggered slides on it on Buck Ridge over the weekend (<a href="https://www.mtavalanche.com/images/22/rider-triggered-avalanche-near-mu…;). For today, it is possible to trigger avalanches and the danger is rated MODERATE.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>&nbsp;</p>

Upcoming Education Opportunities

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events.

Snowboarder Triggered Avalanche Crazy Mountains

Out of Advisory Area
Code
HS-ARu-D1.5-O
Elevation
8000
Aspect
NE
Latitude
46.01870
Longitude
-110.27600
Notes

From IG: "Avalanche in the crazies that caught and carried me today. There were quite a few cars at the trailhead so I thought I’d share so maybe more people knew what the crazies snowpack is like.


Hard wind slab on a NE aspect at 8000ft. The whole seam was about 300feet wide and the toe was maybe 100 feet below the crown at the furthest. Collapsed on buried surface hoar on top of a freeze crust."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Snowboarder
Trigger Modifier
u-An unintentional release
D size
1.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
6.0 inches
Vertical Fall
100ft
Slab Width
300.00ft
Weak Layer Grain type
Surface Hoar
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year