19-20

GNFAC Avalanche Forecast for Sun Oct 27, 2019

Snowpack and Avalanche Discussion

<p>While it’s not even Halloween yet, it is sure feeling like winter. Snow coverage is improving with 1-3 ft of settled snow in the mountains and a layered snowpack beginning to develop. Whether you’re enjoying the opening weekend of rifle season, sneaking in some early season turns, or seeking out ice to climb, you need to be thinking about avalanches and choosing your terrain carefully. Give the early season snow the respect it deserves, avalanche accidents and fatalities can and have happened in October (<strong><a href="https://www.mtavalanche.com/accident/17/10/12">accident report</a></strong>).</p>

<p>With each snowfall the snowpack is getting more complex: this weekend’s snow is sitting on last weekend’s settled snow, which in some areas is sitting on snow that fell earlier in the month. Over the last few days we’ve gotten reports of snow at the ground becoming weak and faceted with unstable test results in the Bridgers and Hyalite, and an avalanche that broke near the ground in the southern Madison Range (<strong><a href="https://www.mtavalanche.com/node/20831">details</a></strong&gt;). It’s still early season, so we don’t yet have a great handle on the distribution of these weak layers, or know how reactive they will be. This uncertainty merits additional caution. Before getting on a steep slope dig down to find out what’s lurking beneath your feet, then <a href="https://www.mtavalanche.com/node/add/snow_observation">drop us a line</a> when you get home so we can share what you’ve found with the rest of the community. We’re reaching a nasty time when there is enough snow to create a larger avalanche but many rocks and other obstacles are still not buried so the consequences of getting caught in any slide, regardless of size, will be high.</p>

<p>Skiers yesterday at Bridger triggered small avalanches within the new snow (<strong><a href="https://www.mtavalanche.com/images/19/soft-slab-bridger">photo</a></str…;). This is a good reminder that although it may feel safe because the terrain is so familiar, while the ski area is closed there is no avalanche mitigation occurring and backcountry avalanche conditions exist.</p>

<p>We are preparing for winter, setting up weather stations and beginning to collect snowpack information. If you have avalanche, snowpack or weather observations to share, please submit them via our <u><strong><a href="https://www.mtavalanche.com/node/add/snow_observation">website</a></str…;, email (<u><strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong></u&gt;), phone (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.

BOZEMAN

6 November, 1-hr Avalanche Awareness, 6-7pm @ REI Bozeman.

7 November, 1-hr Avalanche Awareness, 6-7pm @ Langford Hall, MSU.

Small avalanches at Bridger

Bridger Bowl
Bridger Range
Code
SS-AS-R1-D1
Latitude
45.81560
Longitude
-110.92300
Notes

Small storm slabs triggered at Bridger Bowl on 10/26. From email: "slab formation appeared isolated to leeward sides of midslope terrain features and rollovers as well as at ridgetops". 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
1
D size
1
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Small storm slabs triggered at Bridger on 10/26. From email: "slab formation appeared isolated to leeward sides of midslope terrain features and rollovers as well as at ridgetops". 

Photo: G. Antonioli

Bridger Range, 2019-10-27

From obs.: "Dug a few hasty pits and found the snowpack to be pretty saturated all the way to the ground until around 9,500ft. The upper parts of the Blackmore east face had well over 3ft of snow, and was still dry and faceted at the base. Picture is a pit from around 9,700ft on Blackmore... 115cm deep. Wet snow made up about 2/3rds of the snowpack, on top of a sun crust with dry basal facets below." Photo: C. Kussmaul

Northern Gallatin, 2019-10-26

Small Wind Slabs on Mt Blackmore

Mt Blackmore
Northern Gallatin
Code
SS-AS-R1-D1
Aspect
E
Latitude
45.44440
Longitude
-111.00400
Notes

A skier reported lots of wind transport and triggering several thin wind slabs on the east face of Mt. Blackmore, in the northern Gallatin Range (10/25).

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
1
D size
1
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year