22-23

Natural wet slide, Close Call/slushman ravine

Date

Pics below of a natural wet slide that came out of Close Call yesterday afternoon (4/11/23), debris ran to the bottom of moonshine.

Region
Bridger Range
Location (from list)
Bridger Bowl
Observer Name
BBSP

Wet Slides running far into North Bowl at Bridger

Date
Activity
Skiing

Although I only photographed North Bowl slides that ran very far, most of the chutes showed signs of wet slides running from the ridge. These were both in the bowl next to PK and north bowl.

Region
Bridger Range
Location (from list)
Bridger Bowl

GNFAC Avalanche Forecast for Wed Apr 12, 2023

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Last weekend an abrupt change to spring brought above freezing temperatures and sunshine that melted the snowpack for the first time this season. Dangerous wet snow conditions developed over the last two days after temperatures did not freeze for two nights in a row. There were large cornice breaks (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/cornice-fall-mount-abundance"><sp…. Abundance</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/giant-cornice-collapse-north-madi… Madison</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), and a few natural wet slabs and multiple wet loose avalanches large enough to bury a person and snap small trees (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29074"><span><span><span><strong><span… on Baldy</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29078"><span><span><span><strong><span… Peak</span></span></u></span></strong></span></span></span><span><span><span><span><span><u><span><span> </span></span></u></span></span></span></span></span><span><span><span><strong><span><u><span><span>and</span></span></u></span></strong></span></span></span><span><span><span><span><span><u><span><span> </span></span></u></span></span></span></span></span><span><span><span><strong><span><u><span><span>Bridger</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29080"><span><span><span><strong><span… Sky</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29071"><span><span><span><strong><span… road in YNP</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Last night’s below freezing temperatures froze the snow surface and helped stabilize the snowpack, and today cooler temperatures and clouds will reduce the chances of natural wet snow avalanches. However, a person could still trigger large wet avalanches on steep slopes where the snowpack did not freeze overnight, or where the snow surface becomes soft and wet from above freezing temperatures today. If tonight’s storm begins as rain it could quickly weaken the snowpack and make wet avalanches more likely. Avoid travel on and underneath steep slopes where the snow surface is not frozen, start early and anticipate the snow to become weaker later in the day. Give cornices a wide berth along ridgelines and avoid slopes directly below them.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Tomorrow, wet snow avalanches will become less likely, but heavy new snow will create dangerous avalanche conditions. Avoid steep terrain during the storm, and before crossing or riding any steep slopes carefully assess the stability of new and wind-drifted snow. More heavy snowfall may cause deeper avalanches to break on old persistent weak layers (recent deep slabs: </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29012"><span><span><span><strong><span… Madison Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/29004"><span><span><span><strong><span… Gallatin Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28949"><span><span><span><strong><span… Area</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28900"><span><span><span><strong><span… Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), so your best bet is to choose simple, low angle terrain, especially during and immediately after storms.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>There is still a full list of avalanche hazards to manage if you are out in the mountains this spring. Our </span></span></span></span></span></span><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span><span><span… and weather log</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> shows avalanche activity occurred on most days for the past few months, and avalanches are not stopping quite yet.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>We will issue spring snowpack and weather updates twice a week through April, and we will share relevant avalanche and snowpack information on our website and social media. If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).</span></span></span></span></span></span></p>

INFO and REMINDERS

Bridger Bowl Ski Area is closed, and ski patrol is no longer performing rescues and making terrain closure decisions for you (video).

Natural full depth wet slides in closed terrain at Big Sky

Big Sky Resort
Northern Madison
Code
WL-N-R2-D2-O
Elevation
10000
Aspect
S
Latitude
45.27600
Longitude
-111.43600
Notes

From Big Sky Ski Patrol: "Temps remained a little cooler than yesterday and generally topped out in the mid 40’s F. That didn’t stop the free water from moving
and continuing to destabilize the snowpack, primarily on solar aspects below 10,000’. Near full depth to full depth wet loose avalanches continued to naturally release in what was left of the A-Z’s as well as LRT which had not seen any activity yesterday."

Number of slides
5
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From Big Sky Ski Patrol: "Temps remained a little cooler than yesterday and generally topped out in the mid 40’s F. That didn’t stop the free water from moving
and continuing to destabilize the snowpack, primarily on solar aspects below 10,000’. Near full depth to full depth wet loose avalanches continued to naturally release in what was left of the A-Z’s as well as LRT which had not seen any activity yesterday." Photo: BSSP

Northern Madison, 2023-04-12

Natural full depth wet slide in closed terrain at Big Sky

Date

From Big Sky Ski Patrol: "Temps remained a little cooler than yesterday and generally topped out in the mid 40’s F. That didn’t stop the free water from moving
and continuing to destabilize the snowpack, primarily on solar aspects below 10,000’. Near full depth to full depth wet loose avalanches continued to naturally release in what was left of the A-Z’s as well as LRT which had not seen any activity yesterday."

Region
Northern Madison
Location (from list)
Big Sky Resort
Observer Name
BSSP

Natural wet slides in Bridger Range

Bridger Bowl
Bridger Range
Code
WL-N-R2-D2
Elevation
8300
Aspect
E
Latitude
45.81560
Longitude
-110.92300
Notes

From 4/11/23: Yesterday (4/10) Colters released a wet slide (approx 1-3pm) that filled the top of the wiggle and left debris 300ft past the south bowl traverse.

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
R size
2
D size
2
Problem Type
Wet Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural wet slides on Saddle Peak and Bridger

Saddle Peak
Bridger Range
Code
WS-N-R1-D2-O
Elevation
8700
Aspect
NE
Latitude
45.79640
Longitude
-110.93400
Notes

From 4/11/23: Yesterday (4/10) Colters released a wet slide (approx 1-3pm) that filled the top of the wiggle and left debris 300ft past the south bowl traverse (separate avalanche log entry). Today Stupor had a similar sized release just after noon.

The best noted natural release was a wet slab release on the southern edge of the football field that put a pile of debris below the cave.

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
1
D size
2
Bed Surface
O - Old snow
Problem Type
Wet Snow
Vertical Fall
1000ft
Slab Width
40.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year