20-21

Eaglehead (Portal Creek)

Date
Activity
Skiing

105 cm on the ground on the north side of Eaglehead Mountain today. The lower 60 cm is all various types of facets, with another 30-50 cm of new snow from the past few days on top. Stability tests were kind of all over the place but they all concluded with an “N” breaking somewhere near the middle of the snowpack. Our snow pit observations were confirmed by lots of wumphing and shooting cracks on the way up. Despite ripping winds and a lot of snow transport going on the ski conditions were still quite good at and below tree line.

Region
Southern Gallatin
Observer Name
Henry Coppolillo

Frazier Basin

Date
Activity
Skiing

Strong winds ripped out of the North all morning. At times even nearly blowing me over if they caught me off balance. Little to no wind transported snow accumulating on the S face of pass between fairy lake and frazier basin (above exit gully). We skied a run down exit gully on mixed glacial ice from storm two weeks ago, and more recent chalky breakable windboard. Did not encounter any wind slabs cracking beyond our skis, despite several efforts at kicking off wind slabs. Our descent back to the fairy lake involved some walking downhill to avoid massacring our skis.

On a side note, in an older truck with decent tires we easily made it to the second parking lot along the fairy lake road, we could have easily gone a bit further, but would have maybe not quite made it to the flats below the lake. Some dedicated folks who gave it several attempts did finally make it though.

Region
Bridger Range
Location (from list)
Frazier Basin
Observer Name
Nick Benoit

GNFAC Avalanche Forecast for Sat Nov 14, 2020

Snowpack and Avalanche Discussion

<p>Wind has been blowing strong out of the west and will continue this weekend. Up to 4” of snow fell around Bozeman and Big Sky which will be drifted into wind slabs at all elevations. On Thursday skiers triggered a 50 foot wide and 6” deep wind slab near Fairy Lake in the Bridger Range (<a href="https://www.mtavalanche.com/images/20/wind-slab-n-bridgers"><strong><u>…;). Last night’s snow and wind will create more opportunities to trigger avalanches. Although these may be thin and small, don’t be fooled, they can beat you up on the rocks, sweep you off your feet and bury you.&nbsp;</p>

<p>The southern ranges including the mountains around West Yellowstone and Cooke City got a foot of snow (1” <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</u></a>) with strong west wind. The snow fell on dirt around West Yellowstone while Cooke City has over 40” above 9,000’ (<a href="https://www.mtavalanche.com/weather/stations/fisher-creek"><u>Fisher Creek Snotel</u></a>). Slabs of wind blown snow will be widespread and a couple feet thick. I expect a skier or sledder could easily trigger these slopes this weekend. Shooting cracks, collapses and recent avalanche activity, no matter how small, are signs of avalanche danger. Heed the obvious and be extra careful crossing steep, snow covered slopes no matter if you are on foot, skis or snowmobile.&nbsp;</p>

<p>Early season sliding and riding has a unique set of issues: colliding with thinly buried obstacles, being rusty in evaluating snow stability, and not maintaining or being practiced with our rescue gear. I recommend watching Dave’s new 3-minute video where he demonstrates how to do a quick beacon drill (<a href="https://youtu.be/p1xuaaSq4YU"><strong><u>video</u></strong></a&gt;). If you are hungry for more you can watch my 1-hour lecture on Early Season conditions <a href="https://youtu.be/vyKdBBzd5IE"><strong><u>here</u></strong></a>.</p&gt;

<p>Every day we will update the <a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><strong><u>weather log</u></strong></a>, <a href="https://www.mtavalanche.com/photos"><strong><u>photos page</u></strong></a> and <a href="https://www.mtavalanche.com/avalanche-activity"><strong><u>avalanche activity list</u></strong></a>.&nbsp; We will continue issuing early season updates and transition to daily avalanche forecasts when we get more snow. If you have avalanche, snowpack or weather observations to share, please submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

Upcoming Avalanche Education and Events

See our education calendar for an up to date list of all local classes. Here are a few select upcoming events and opportunities to check out:

Monday, November 16, 7-8:30 p.m. The 6th Annual MSU Snow and Avalanche Workshop Research Roundup: New and expanded research. This is a free online event.

Hyalite Main Fork

Date

A blustery day up there today. Intense snow transport at all elevations including well below treeline. Biggest hazard was falling trees!

Observer Name
Sam H

GNFAC Avalanche Forecast for Fri Nov 13, 2020

Snowpack and Avalanche Discussion

<p>This week’s new snow and strong winds brought avalanches along with them. Yesterday, skiers in the northern Bridger Range triggered a small wind slab that broke 6” deep and 50 ft wide (<a href="https://www.mtavalanche.com/images/20/wind-slab-n-bridgers"><u>photo</u…;). Another similar slide was reported in the area as well. This is a good reminder that it doesn’t take a lot of new snow to cause avalanches, especially when there are strong winds to drift that snow around. Stay on alert - we will have both more new snow and more strong winds over the next few days.&nbsp;</p>

<p>Snow coverage is still spotty in most areas. Slopes with the most coverage&nbsp;are generally wind drifted, shady, and higher elevation. They have been holding snow through the last month and a layered snowpack has started to develop. Whether you’re seeking out these slopes intentionally to ski or ride, or crossing them incidentally while pursuing another activity, careful assessment is needed if you’re getting into avalanche terrain.&nbsp;</p>

<p>Watch for shooting cracks, collapses, and recent avalanches as bulls-eye data the snow is unstable. Uncertainty is especially high this time of year - take a few minutes to get your shovel out to assess the snowpack before crossing any steep snow covered slope.</p>

<p>We’ll be updating the <a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><strong><u>weather log</u></strong></a>, <a href="https://www.mtavalanche.com/photos"><strong><u>photos page</u></strong></a> and <a href="https://www.mtavalanche.com/avalanche-activity"><strong><u>avalanche activity list</u></strong></a> daily and issuing early season updates throughout the fall as conditions merit. If you have avalanche, snowpack or weather observations to share, please submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

Upcoming Avalanche Education and Events

See our education calendar for an up to date list of all local classes. Here are a few select upcoming events and opportunities to check out:

The 6th Annual MSU Snow and Avalanche Workshop will be an hour of live online talks each Monday evening in November. 

Small skier triggered slides in Northern Bridgers

Hardscrabble Peak
Bridger Range
Code
HS-ASu-R1-D1
Latitude
45.91510
Longitude
-110.98100
Notes

On 11/12, two small slides were reported in the Northern Bridger Range near Fairy Lake, at least one of which was skier triggered.

The skier triggered slide was "a wind slab approximately 50 X 50’ with a 6” crown. The slab itself was only about 4” thick and only slid about 5” down the slope before stopping, and I was able to stop and then turn around and ski off of the slab without it moving any further. The 4” of dry slab was sitting on about 3” of sugary snow that was on a very firm icy bed surface."

We don't have details on the other slide, but it was reported as a wind slab avalanche on the NE side of Pomp Peak.

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Skier
Trigger Modifier
u-An unintentional release
R size
1
D size
1
Slab Thickness
6.0 inches
Vertical Fall
50ft
Slab Width
50.00ft
Images
Skier triggered hard wind slabs near Hardscrabble peak
Wind slab in N Bridgers
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
20-21

From obs: "while I was skinning up to the rollover I popped off a wind slab approximately 50 X 50’ with a 6” crown. The slab itself was only about 4” thick and only slid about 5” down the slope before stopping, and I was able to stop and then turn around and ski off of the slab without it moving any further. The 4” of dry slab was sitting on about 3” of sugary snow that was on a very firm icy bed surface." Photo: Anonymous

Avalanche Details: Small skier triggered slides in Northern Bridgers
Forecast link: GNFAC Avalanche Forecast for Fri Nov 13, 2020GNFAC Avalanche Forecast for Sat Nov 14, 2020GNFAC Avalanche Forecast for Thu Nov 19, 2020
Bridger Range, 2020-11-13
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