19-20

From obs (4/12/20): "Noticed this slide yesterday evening on the way out of Beehive Basin, on the southeast facing aspect. It appeared to have come all the way down from the upper portion of the ridge on steeper slopes. We figured it slid sometime Thursday or Friday in the high temps. There were several other debris paths, but this was the biggest by far." Photo: @davidgerstenberger

Northern Madison, 2020-04-13

From obs (4/12/20): "Noticed this slide yesterday evening on the way out of Beehive Basin, on the southeast facing aspect. It appeared to have come all the way down from the upper portion of the ridge on steeper slopes. We figured it slid sometime Thursday or Friday in the high temps. There were several other debris paths, but this was the biggest by far." Photo: @davidgerstenberger

Northern Madison, 2020-04-13

GNFAC Avalanche Forecast for Mon Apr 13, 2020

Snowpack and Avalanche Discussion

<p>Today and tomorrow avalanches will involve snow that fell the last couple days. These could be small loose snow slides or fresh wind slabs. Yesterday small dry loose avalanches ran naturally (<strong><a href="https://www.mtavalanche.com/node/22726">details</a></strong&gt;), and wind slabs were triggered by skiers in the Bridger Range (<strong><a href="https://www.mtavalanche.com/images/20/small-skier-triggered-slide-bridg…;) and Beehive Basin (<strong><a href="https://www.mtavalanche.com/node/22722">photo/details</a></strong&gt;). Wind from the east and north formed fresh drifts in less common locations which are possible to trigger today.</p>

<p>More snow tomorrow night through Wednesday will create unstable, dangerous avalanche conditions during and following the storm. Avalanches will become easy to trigger. The amount of snow and wind will determine the size of hazards, but any avalanche can be deadly in the wrong spot. Be extra cautious this week and choose objectives that keep you close to home and out of harm’s way.</p>

<p>Be ready to change plans if you find unexpected conditions or changing snow stability. Even with today’s frigid temperatures, the&nbsp;high spring sun will decrease strength of recent snow as the surface becomes wet and make avalanches easier to trigger. The safest plan is to avoid avalanche terrain. If you ride steeper slopes, reduce consequences by choosing terrain where a slide will not carry you through rocks, trees or over cliffs. Carefully assess and re-assess snow stability. Anticipate stability to change more drastically from hour-to-hour or day-to-day than what we are used to during winter.</p>

<p>Please continue to send us your observations. You can fill out an <a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank">observation form</a>, email us (<a href="mailto:mtavalanche@gmail.com&quot; target="_blank">mtavalanche@gmail.com</a>), leave a VM at 406-587-6984, or Instagram (#gnfacobs). We greatly appreciate your support.</p>

GNFAC Forecaster Chat

TONIGHT!!! @ 6-7 p.m. GNFAC Forecaster Chat: Spring snowpack and travel advice, Live Online w/ Uphill Pursuits. Link here for details and to join the discussion.

Fro obs 4/12/20: "We noted a [small] avalanche that had been (likely) human triggered just north of 3/4 Rock on A-Route. The slide ran almost all the way to the cat road in the bowl. I found variable conditions on the ridge, from about 4 inches of light density snow, to wind slab up 3ft. thick and punchy..." Photo: M. Standal

Bridger Range, 2020-04-13

Wind slabs, cracking and dry loose avalanches Bridgers

Ross Peak
Bridger Range
Code
L-N-R1-D1
Elevation
8000
Aspect
E
Latitude
45.85860
Longitude
-110.95600
Notes

From obs (4/12/20): "Toured in the middle bridgers today... There was 6-8" of new snow on top of a supportable crust on all aspects. We got some shooting cracks skinning up Texas that propagated about 10-15' wide and 6-8" deep. Also saw some natural dry loose slides on steep terrain near the ridge and up high on Ross. Lots of skier traffic in the area, with some dry loose slides, but nothing bigger than D1.

The best sight-seeing was on the main slide path on the east face of Ross. We saw 4 or 5 old growth trees in the middle of the path that had branches broken off up to 30' high, and a handful of 8" diameter trees that had been ripped out of the ground and deposited at the bottom of the path. Looked like this carnage was from this season; maybe the big cycle mid-feb? Did Ross slide big this year? I saw some pics from the Throne on the website, but nothing on Ross."

Two other groups found similar conditions at Bridger Bowl.

"Went for a short tour up Slushmans today. Light boot top powder had been blown into soft windslabs in odd locations on the upper third of the mountain. Observed some small loose dry slides in steep terrain. The snow down low was getting a little wet but the cold air seemed to be keeping it cool enough to prevent wet avalanches."

"We noted a [small] avalanche that had been (likely) human triggered just north of 3/4 Rock on A-Route. The slide ran almost all the way to the cat road in the bowl. I found variable conditions on the ridge, from about 4 inches of light density snow, to wind slab up 3ft. thick and punchy."

Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Natural trigger
R size
1
D size
1
Problem Type
New Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Wet slides in southern Madison

Beaver Creek
Southern Madison
Code
WL-N
Elevation
9500
Latitude
44.87200
Longitude
-111.36100
Notes

Skiers in Beaver Creek in southern Madison Range on 4/12/20 reported: "...There were probably a couple dozen [wet slides] in total, including several small ones that ran into Beaver Creek road. Every solar aspect had multiple slides from the past few days of warm weather, at elevations from the road up to 10000', but none were larger than any my partner and I observed near Lionhead on 4/9 (≤D2)." Photo: S. Reinsel

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Skiers in Beaver Creek in southern Madison Range on 4/12/20 reported: "...There were probably a couple dozen [wet slides] in total, including several small ones that ran into Beaver Creek road. Every solar aspect had multiple slides from the past few days of warm weather, at elevations from the road up to 10000', but none were larger than any my partner and I observed near Lionhead on 4/9 (≤D2)." Photo: S. Reinsel

Southern Madison, 2020-04-13

Snowboard triggered wind slabs in Beehive

Beehive Basin
Northern Madison
Code
HS-AS-R2-D1.5-O
Elevation
9500
Latitude
45.34070
Longitude
-111.39100
Notes

Fresh wind slabs were triggered around a foot thick in Beehive Basin on Sunday 4/12/20.

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Skier
R size
2
D size
1.5
Bed Surface
O - Old snow
Slab Thickness
12.0 inches
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year