18-19
This dry loose avalanche was intentionally triggered by a skier in Hyalite. Although generally small, dry loose avalanches can generate enough force to push skiers or riders into rocks or trees. Photo: C. Kussmaul
Avalanche Details: Small dry loose avalanches Hyalite
Forecast link: GNFAC Avalanche Forecast for Fri Mar 15, 2019GNFAC Avalanche Forecast for Sun Mar 17, 2019
Northern Gallatin, 2019-03-14
Forecast link: GNFAC Avalanche Forecast for Fri Mar 15, 2019GNFAC Avalanche Forecast for Sun Mar 17, 2019
GNFAC Avalanche Forecast for Thu Mar 14, 2019
Snowpack and Avalanche Discussion
<p>Yesterday’s storm dropped 6” of snow in Hyalite with north winds blowing 10-20 mph. This is enough to increase the likelihood of triggering slides in the new snow. This snow fell onto ice or wind crusts which will aid in triggering loose avalanches: dry ones in the morning, and wet in the afternoon on sun exposed slopes. Wind drifts near the ridgelines are suspect as well. I do not expect slides to break deeper than the new snow, but these 6+” will be reactive and could push you into a terrain trap. For today, avalanches are possible and the danger is rated <strong>MODERATE</strong>.</p>
<p>Three skiers on Tuesday triggered a slide near Beehive Peak. It was confined to new, windblown snow and broke 6-8” deep, 100 feet wide and 600 feet vertical (<strong><a href="https://www.mtavalanche.com/node/20386">details and photos</a></strong>). On Saturday skiers triggered a similar slide nearby, but it stepped down into deeper snow and created a large avalanche (<u><strong><a href="https://www.mtavalanche.com/node/20359">details and photos</a></strong></u>). Luckily, this did not happen on Tuesday since all 3 skiers were on the slope at the same time.</p>
<p>Yesterday, I toured into Beehive and Bear Basins and found small facets near the surface (<strong><a href="https://www.mtavalanche.com/images/19/near-surface-facets-under-ice-cru…;) and sugary facets in the bottom of the snowpack (<strong><a href="https://www.youtube.com/watch?v=zDZIGxGxCgY&index=2&list=PLXu51…;). This lower layer was not breaking in stability tests, but as the avalanche on Saturday illustrates they are still a player. Given the recent avalanche activity and known weak layers, the avalanche danger is rated <strong>MODERATE</strong> since avalanches remain possible. Additionally, sun exposed slopes may have wet loose avalanches if skies clear this afternoon.</p>
<p>Without new snow, the Bridger Range, southern Gallatin and southern Madison Ranges, and mountains around Cooke City and West Yellowstone are generally stable. This week Ian was near Hebgen Lake (<u><strong><a href="https://www.youtube.com/watch?v=TCn1ZXThYzM&list=PLXu5151nmAvRNl9ku…;), Eric was in the southern Gallatin Range (<u><strong><a href="https://www.youtube.com/watch?v=CqDjipxrGwM&list=PLXu5151nmAvRNl9ku…;) and I was in Cooke City (<u><strong><a href="https://www.youtube.com/watch?v=P4oCbQ5oIHU&index=2&list=PLXu51…;). We all found weak layers in the snowpack, some near the ground and others near the surface, but triggering them is unlikely. The weak layer near the surface does not require much digging to test. If the snow propagates in a stability test, reevaluate your travel plan.</p>
<p>For today, the dry snow avalanche danger is rated<strong> LOW</strong>. Additionally, sun exposed slopes may have wet loose avalanches if skies clear this afternoon.</p>
<p>If you get out and have any avalanche or snowpack observations to share, contact us via our <u><a href="https://www.mtavalanche.com/node/add/snow_observation">website</a></u>, email (<u><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></u>), phone (406-587-6984), or Instagram (#gnfacobs).</p>
Skier triggered slide NE of Beehive Peak
Beehive Basin
Northern Madison
Code
SS-ASu-R2-D2-I
Elevation
9600
Aspect
NE
Latitude
45.35450
Longitude
-111.40000
Notes
A group of skiers watched another group trigger a large wind slab avalanche near Beehive Peak. Luckily, none were caught or buried. From the email:
"On Tuesday (3/12) we observed 3 skiers trigger an avalanche on the north face of Peak 10,602 (the summit just NE of Beehive Peak). We saw the event unfold from a distant ridge, but was able to see that none of them were caught. Later in the day, we ended up at the base of the slope that avalanched and determined the issue to be the same wind slab we had been encountering on numerous N and NE slopes throughout the day. The crown depth was 6-8 inches and was about 100ft wide. The avalanche ran at least 600 vertical feet."
Number caught
0
Number buried
0
Number killed
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
u-An unintentional release
R size
2
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
7.0 inches
Vertical Fall
600ft
Slab Width
100.00ft
Slab Layer Grain Type
Wind packed
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
A skier reported watching a group trigger this windslab near Beehive Peak. Slab was 6-8" thick, 100' wide, and ran for around 600'. Luckily, nobody was caught or buried. This photo was taken near the toe of the debris pile.
Avalanche Details: Skier triggered slide NE of Beehive Peak
Forecast link: GNFAC Avalanche Forecast for Thu Mar 14, 2019
Northern Madison, 2019-03-13
Forecast link: GNFAC Avalanche Forecast for Thu Mar 14, 2019
A skier reported watching a group trigger this windslab near Beehive Peak. Slab was 6-8" thick, 100' wide, and ran for around 600'. Luckily, nobody was caught or buried. Skiers are circled in the bottom left of the frame for scale.