18-19

Skier Triggered Wind Slab, Bridger Range.

Wolverine Bowl
Bridger Range
Code
SS-AS-R1-D1-S
Elevation
8300
Aspect
NE
Latitude
45.82910
Longitude
-110.93400
Notes

Strong winds in the Bridger Range formed dense slabs on leeward slopes. Yesterday, A skier north of Bridger Bowl triggered multiple wind slabs near the top of Wolverine Bowl. The skier turned around and chose a safer objective. Photo: S. Whitefields 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
1
D size
1
Bed Surface
S - Avalanche released within new snow
Problem Type
Wind Slab
Slab Thickness
30.0 centimeters
Slab Width
15.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Strong winds in the Bridger Range formed dense slabs on leeward slopes. Yesterday, A skier north of Bridger Bowl triggered multiple wind slabs near the top of Wolverine Bowl. The skier turned around and chose a safer objective. Photo: S. Whitefields 

Bridger Range, 2018-11-13

Climber triggered wind slab in Flanders

Flanders Creek
Northern Gallatin
Code
SS-AFu-R0-D1-O
Elevation
9000
Aspect
SE
Latitude
45.44290
Longitude
-110.93200
Notes

Climbers triggered this very small wind slab on the way to a climb up Flanders in Hyalite (11/11). A tiny slide to a skier can be bad news for a climber since losing one's balance or getting pushed off a cliff can be deadly. From an email (edited):

Hyalite Snow Conditions:...we dug two hasty pits on east facing slopes in Flanders....
8200'- isolated opening in trees in an area on rocks, shallower snow (~50cm). CT12 at the ground, again just tapping on the back of other hand, so not super legit, but did raise eyebrows.  
8450'- Opening below cliff bands on exposed traverse. Deeper snow (~80-90cm). No concerns other than storm snow and snow coming off of cliff bands.  Classic Hyalite shifty winds.  We released a small (10-15cm) storm slab on traverse into the climb .  
Weather: It was snowing and blowing all day.

Photo: S. Magro

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Foot penetration
Trigger Modifier
u-An unintentional release
R size
0
D size
1
Bed Surface
O - Old snow
Problem Type
Wind Slab
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Climbers triggered this very small wind slab on the way to a climb up Flanders in Hyalite (11/11). A tiny slide to a skier can be bad news for a climber since losing one's balance or getting pushed off a cliff can be deadly. From an email (edited):

Northern Gallatin, 2018-11-12

GNFAC Avalanche Forecast for Mon Nov 12, 2018

Snowpack and Avalanche Discussion

<p>It has snowed somewhere in our forecast area 13 out if the last 14 days (<strong><a href="https://www.mtavalanche.com/weather/wx-avalanche-log">weather log</a></strong>). The mountains around Bozeman and Cooke City have 3-4’ of snow on the ground with 2-4’ measured around Big Sky and West Yellowstone. The snowpack has a good structure: it is dense near the ground and supports our weight and lacks widespread weak layers. This is a positively refreshing start to the season!</p>

<p>Wind-loading is our #1 avalanche concern. On Friday and again on Sunday, ice climbers triggered small avalanches on a wind-loaded slopes up Hyalite (<strong><a href="https://www.mtavalanche.com/avalanche-incidents">details</a></strong&gt;, <strong><a href="https://www.mtavalanche.com/images/18/ice-climber-triggered-slab">photo…;, <strong><a href="https://www.mtavalanche.com/images/18/small-wind-slab-triggered-flander…;) and on Saturday a snowboarder released a wind-slab in Middle Basin north of Big Sky (<strong><a href="https://www.mtavalanche.com/images/18/middle-basin-avalanche">photo</a>…;, <strong><a href="https://www.mtavalanche.com/node/19028">details</a></strong&gt;). Westerly winds are forecasted to pick up today and remain strong until mid-week, blowing powder into wind-drifts that could be easily triggered. A common warning sign on wind-loaded slopes are cracks shooting out in front of your skis.</p>

<p>It is early season and we are still formulating an overall picture of the snowpack. Our <strong><a href="https://www.mtavalanche.com/photos">photos</a></strong&gt; page and <strong><a href="https://www.mtavalanche.com/snowpits">snowpit profiles</a></strong> detail the information we are gathering and are worth a quick study. In general we are conservative in our snowpack assessments this time of year. Last Tuesday a large avalanche was triggered by the Big Sky Ski Patrol (<strong><a href="https://www.mtavalanche.com/node/18990">details</a></strong&gt;), and skiers found weak snow (<strong><a href="https://www.mtavalanche.com/images/18/facets-below-crust">facets</a></s…;) in Hyalite and Cooke City. It’s important to dig and test the snow to rule out potential dangers. Once we get more information and more snowfall we will start issuing daily advisories and danger ratings.</p>

<p>New this season, we added hyperlinks to the <strong><a href="https://www.mtavalanche.com/weather/wx-avalanche-log">Weather and Avalanche Log</a></strong> and a new Menu item &lt;<strong><a href="https://www.mtavalanche.com/avalanche-activity">Avalanches and SnowPits</a></strong>&gt; with information on avalanche activity and incidents.</p>

<p>We are preparing for winter, scheduling avalanche classes, and setting up weather stations. If you get outside send us an observation via our website, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a&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: Events and Education Calendar.

November 14, 1-hr Avalanche Awareness, 6-7pm at Spire Climbing Center

November 14, 1-hr Avalanche Awareness, 6-7pm at Round House Sports

November 26, MSU Snow and Avalanche Workshop, 5-9pm at MSU SUB Ballroom A