19-20

Natural wet avalanches in Pine Creek, Livingston

Pine Creek
Out of Advisory Area
Code
WL-Nu
Latitude
45.49040
Longitude
-110.48500
Notes

My partner and I were snowshoeing to Pine Creek Lake on Saturday 3/7 when we came across a large amount of avalanche debris piled up in the creek bed/gully of the north fork of Pine Creek. The toe of the debris started approximately right where the normal summer trail crosses the Pine Creek, and ran for probably a couple hundred feet up the creek bed. As we paralleled the creek on the south side, we could eventually see where it looked like the avalanche started, far up on the ridge to the north of the creek, at least another 1000 feet above. The debris looked fresh and very chunky/wet. That Saturday was very warm and sunny. We experienced a few small whumphs/collapses as we hiked up the south side of the creek. We ran into a couple other parties of skiers, but none of them commented on any other particular instabilities higher up towards Black Mtn.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
Trigger Modifier
u-An unintentional release
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Cornice triggered avalanche in Republic Creek, Cooke

Republic Creek
Cooke City
Code
C-N-R2-D2.5
Aspect
E
Latitude
44.98550
Longitude
-109.94100
Notes

The GNFAC saw this on Tuesday morning (3/10) from Woody Ridge. Winds were strong and loading slopes.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Cornice fall
Trigger
Natural trigger
R size
2
D size
2.5
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

GNFAC Avalanche Forecast for Wed Mar 11, 2020

Snowpack and Avalanche Discussion

<p>Today, clouds and wind will keep wet snow avalanches at bay as strong gusts continue to scrape and redistribute snow. Folks that got out yesterday saw wind-loading. Plumes of snow were streaming off the ridges and drifting snow at high elevations (<strong><a href="https://youtu.be/GOIzS2dnGlI">video</a></strong&gt; by GNFAC alumus Eric Knoff). We received many reports from the Bridger Range (<strong><a href="https://www.mtavalanche.com/node/22387">details</a></strong&gt;) of wind slabs avalanching both naturally and getting triggered by skiers. Upwards of 12” of snow since Sunday has been blown into wind slabs throughout the forecast area.</p>

<p>Yesterday, Ian rode into Buck Ridge (<strong><a href="https://youtu.be/NeckTM_Iudk">video</a></strong&gt;) and found wind-loading (<strong><a href="https://www.mtavalanche.com/images/20/very-small-avalanche-new-snow-buc…;) and minor wetting of the snow surface. I took a drive to Cooke City and toured up Woody Ridge. Wind was blowing out of the west scouring slopes and drifting snow at the ridges and in gullies (<strong><a href="https://www.mtavalanche.com/images/20/wind-scoured-slopes-around-cooke-…;). We were unable to get these drifts to crack, but I did not trust them. In the distance we saw one natural avalanche that was triggered by a cornice fall (<strong><a href="https://www.mtavalanche.com/images/20/cornice-triggered-wind-drift-repu…;). Besides our overall concern with wind-loading, our 7-foot deep snowpit revealed no instability (<strong><a href="https://www.mtavalanche.com/images/20/7-foot-dep-snowpack-woody-ridge">…;, <strong><a href="https://youtu.be/fb7damw5EEs">video</a></strong&gt;). We noted sugary facets at the ground are weak and hibernating (<strong><a href="https://www.mtavalanche.com/images/20/woody-ridge-snow-profile-10-march…;), which is not a problem for now, but like a blister, is annoying and must be watched.</p>

<p>Wind drifts are our primary avalanche concern. Recent avalanche activity is the #1 sign that these drifts are unstable with cracking of wind slabs under your skis or sled a close second. For today, the avalanche danger is rated MODERATE on all wind-loaded slopes and LOW on all others.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an <u><a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank">observation form</a></u>, email us (<u><a href="mailto:mtavalanche@gmail.com&quot; target="_blank">mtavalanche@gmail.com</a></u>), 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.

BILLINGS

TOMORROW, March 12, 1-hr Avalanche Awareness, 6-7 p.m. at The Basecamp.

COOKE CITY

Mike Thom, Gardiner District Ranger, stands in a 7-foot deep snowpit at 9900' on Woody Ridge to the south of Cooke City. We found wind-loading to be our primary concern. Facets were still present at the base of the snowpack, but they are stable for now. Photo: GNFAC

Cooke City, 2020-03-11