20-21

Mt Blackmore

Date
Activity
Skiing

Toured up to blackmore and skied the low angle meadow below the east ridge. 6-8” of new snow that fell on a very firm bed surface. I did not dig a pit, but the firm layer under the new snow felt like a wind slab. The firm layer was less prevalent in protected areas.

Region
Northern Gallatin
Location (from list)
Mt Blackmore
Observer Name
Nicholas Salsburg

GNFAC Avalanche Forecast for Sat Jan 30, 2021

Snowpack and Avalanche Discussion

<p>In the mountains south of Big Sky to West Yellowstone new snow has added significant weight to a snowpack that contains multiple buried weak layers, and dangerous avalanche conditions exist. Since Wednesday night these mountains got 18-26” of snow equal to 1.5-2.1” of snow water equivalent (SWE). Avalanches large enough to bury or injure a person are easy to trigger within the new snow, especially where yesterday’s moderate to strong southwest wind formed thicker slabs (<a href="https://youtu.be/mky_kON6nKU"><strong>Dave’s video</strong></a><strong> from Lionhead</strong>). Larger avalanches can break deeper on buried weak layers and could be triggered from lower angle terrain below and adjacent to steep slopes. On Thursday, skiers in the southern Gallatin Range triggered a large collapse in low angle terrain (<strong><a href="https://www.mtavalanche.com/images/21/large-collapse-s-gallatin">photo<…;). Today the avalanche danger is rated CONSIDERABLE. Conservative decision making and cautious route finding are essential.</p>

<p>Near Big Sky and Bozeman, 3-6” of low-density new snow (0.3-0.4” SWE) and light to moderate west-northwest wind formed fresh slabs that can be triggered by skiers and riders. Yesterday afternoon a skier in the northern Madison Range triggered an avalanche in the new snow which propagated wide and broke deeper into weak sugary snow below (<strong><a href="https://www.mtavalanche.com/images/21/dudley-creek-slides">photo</a></s…;). Today similar human triggered avalanches are possible, especially on wind-loaded slopes. The avalanche danger is MODERATE due to fresh drifts adding weight to a weak snowpack.</p>

<p>Near Cooke City, since Thursday morning the mountains got 6-8” of new snow equal to 0.6” of snow water equivalent. Yesterday, moderate south-southwest wind formed fresh drifts that are possible to trigger. These slabs can break deeper and wider on a weak layer of surface hoar or facets buried 18-24” deep. Doug was in Cooke City on Monday and found this layer in his snowpits and in the crown of a snowmobile triggered avalanche (<a href="https://youtu.be/Ui1wdUHE56E"><strong>video</strong></a&gt;, <strong><a href="https://www.mtavalanche.com/images/21/2-avalanches-sheep-mtn">photo of avalanches</a></strong>). Be cautious of steep wind-loaded slopes and avoid steep slopes where you suspect buried weak layers exist. Large avalanches are possible to trigger and the avalanche danger is MODERATE.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong>website<…;, email (<a href="mailto:mtavalanche@gmail.com"><strong>mtavalanche@gmail.com</strong></a…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

King and Queen Fundraiser

February 6th and 7th, Saturday and Sunday, at Bridger Bowl. Due to the pandemic it is a GS race this year. Prizes will be awarded for the fastest race results AND separate prizes for folks who raise the most money over $500. No racing is necessary to compete for the fundraising prizes. Info is HERE.

Large Collapses in S. Gallatin

SOUTHERN GALLATIN RANGE
Southern Gallatin
Code
Latitude
45.04320
Longitude
-110.96200
Notes

From obs: "While skiing a loaded east aspect in the Southern Gallatin, my partner got a large collapse as he started to break trail back to our skin track, cracks shot 20ish feet uphill."

Number of slides
0
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Red Flag
Advisory Year

Skier triggered slides N. Madison

Dudley Creek
Northern Madison
Code
SS-AS-R3-D2-O
Aspect
NE
Latitude
45.28920
Longitude
-111.29600
Notes

The NE facing slopes of Dudley Creek are struggling to hold the new snow. I easily triggered the 6-8" of new and windblown snow but it is also stepping down to the facets buried deeper.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
3
D size
2
Bed Surface
O - Old snow
Problem Type
New Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Dudley Creek

Date
Activity
Snowboarding

The NE facing slopes of Dudley Creek are struggling to hold the new snow. I easily triggered the 6-8" of new and windblown snow but it is also stepping down to the facets buried deeper.

Region
Northern Madison
Location (from list)
Dudley Creek
Observer Name
Stefan Budac