19-20

Human triggered and natural on Buck Ridge

Buck Ridge
Northern Madison
Code
SS-AMc-R2-D1.5-I
Elevation
9300
Aspect
NE
Latitude
45.17190
Longitude
-111.38000
Notes

We triggered an avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020. It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow,18-24" deep.

We also saw a couple natural avalanche crowns 10-18" deep lower down the drainage. I'm sure there were a ton more crowns there, and probably everywhere. through the forecast area. Visibility was limited to 50-100'.

Number of slides
3
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
2
D size
1.5
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Slab Thickness
20.0 inches
Vertical Fall
15ft
Slab Width
25.00ft
Weak Layer Grain type
Precipitation Particles
Slab Layer Grain Type
Precipitation Particles
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

A snowmobiler triggered this avalanche in the second Yellow Mule off Buck Ridge on 2/6/2020 It is on a small roll/cornice "in the flats". It broke within the current 2-3' storm snow. Photo: GNFAC

Northern Madison, 2020-02-06

We saw this natural crown that broke within the current 2-3' storm on a small terrain feature. It is in the second Yellow Mule off Buck Ridge on 2/6/2020. Photo: GNFAC

Northern Madison, 2020-02-06

GNFAC Avalanche Forecast for Thu Feb 6, 2020

Snowpack and Avalanche Discussion

<p>Last night, 8-13” of snow fell from the Bridger Range to Lionhead measuring .6-.8” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a>, aka 6% powder. This is on top of the 8-10” that fell yesterday in the northern ranges. And the wind is blowing with gusts of 40 mph at the ridgetops that is loading slopes on many aspects.</p>

<p>The avalanche story is simple: New snow and wind yesterday, last night and today are creating dangerous avalanche conditions. If there is visibility, which there isn’t, you would see natural avalanches breaking on wind-loaded slopes. And if you get on a steep slope you’ll likely trigger and get buried in an avalanche.</p>

<p>I am basing today’s elevated danger on the fact the snowstorm is near guaranteed to continue. Wind-loaded slopes should be avoided at all costs and every steep slope is untrustworthy. Avalanches will occur in the new snow and some slopes will break far and wide at the ground. Today is a day to avoid avalanche terrain. The danger is rated HIGH.</p>

<p>One key factor in determining today’s danger is our assessment of stability before the storm. Yesterday, Dave and Ian were in the northern Gallatin Range on Wheeler Mountain and found a weak snowpack that will struggle with the weight of new snow (<strong><a href="https://youtu.be/GRc5Q2pB1Bo">video</a></strong&gt;). Our field visits to Hebgen Lake (<u><strong><a href="https://youtu.be/mOgWbF5FXhQ">video</a></strong></u&gt;), Buck Ridge (<u><strong><a href="https://youtu.be/DzBa5RGCwU8">video</a></strong></u&gt;) and Mt. Ellis (<u><strong><a href="https://youtu.be/HgnRrFSl3eU">video</a></strong></u&gt;) showed similar concerns: weak snow at the ground will break with a large load of new snow.</p>

<p>Since the storm started 30 hours ago Cooke City has gotten 8” of snow (.5” <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a>) with moderate wind. A skier was able to get small cracks on wind-loaded slopes yesterday. The avalanche danger has risen with last night’s and today’s forecasted snowfall. Winds are blowing northerly at 15 mph and loading slopes where it is likely you could trigger a slide. On slopes not wind-loaded it’s possible a skier or sledder could trigger an avalanche in the new snow. Furthermore, Cooke City has a layer of weak snow at the ground that is not readily avalanching, but still could. If this layer breaks the avalanche would be large and lethal. Do not get too confident as you tour around in a snowstorm with poor visibility. For today the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes and MODERATE elsewhere.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an&nbsp;<u><strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong></u>, email us (<u><strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong></u&gt;), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.

COOKE CITY

Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.

BOZEMAN