20-21
Forecast link: GNFAC Avalanche Forecast for Fri Apr 2, 2021
GNFAC Avalanche Forecast for Wed Mar 31, 2021
Snowpack and Avalanche Discussion
<p>The snowpack throughout our advisory area is a mixed bag of conditions: powdery or windblown up high, mashed potatoes down low. The chances of triggering an avalanche is decreasing without a load of new snow or active wind-loading, but it still remains possible. There was natural avalanche activity on wind-loaded slopes Sunday and Monday. Winds hit 100 mph Sunday night and felled trees which Ian and Dave had to lumberjack through to get into Taylor Fork yesterday. They found recent avalanches in Sunlight Basin (<a href="https://www.mtavalanche.com/images/21/natural-avalanche-sunlight-basin"…;) and Sage (<a href="https://www.mtavalanche.com/images/21/natural-avalanche-sage-basin-0"><…;), and caution us that we can still trigger wind slabs (<a href="https://youtu.be/kbS857qFfw8"><strong><u>video</u></strong></a>). </p>
<p>Deeper in the snowpack are sugary facets (depth hoar) near the ground. Over the weekend a skier triggered an 8-10’ deep avalanche on this layer on Mt Blackmore (<a href="https://www.mtavalanche.com/node/24732"><strong><u>photos and details</u></strong></a>), and another deep slide was seen in Flanders Creek (<a href="https://www.mtavalanche.com/images/21/natural-deep-slab-near-flanders">…;) and MacAtee Basin (<a href="https://www.mtavalanche.com/node/24748"><strong><u>photo and details</u></strong></a>). This layer has been a non-stop worry since November and these slides illustrate that being worried is still warranted. </p>
<p>The sun will be strong today, but wind and cool temperatures will temper wet avalanches from getting big. On sunny slopes expect small, loose, wet slides in the top few inches of the snowpack.</p>
<p>Being outside on a beautiful day will feel wonderful, but has no bearing on snowpack stability. Wind-loaded slopes can still be triggered. Before you commit to avalanche terrain dig down a couple feet and confirm there is not an unstable layer underfoot. Overall, triggering slides remains possible and if you are extra unlucky, they could break deep. Today the avalanche danger is rated MODERATE on all slopes. </p>
<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>
Upcoming Avalanche Education and Events
See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:
April 5, 6:30 p.m., Forecaster Chat with Alex Marienthal, hosted by Uphill Pursuits, “Spring Snowpack and Forecasting Tools”. Link to Join.
Dudley Creek
Date
The attached snowpit profile is associated with my observations submitted on 3/27.
Region
Northern Madison
Location (from list)
Dudley Creek
Observer Name
Erich Schreier
Deep Creek
Date
Activity
Skiing
Today we toured up the N-NW burn area above Deep Creek in the Absarokas. The near surface facets were available in abundance at this location. We observed cracking of the recent snow/ facet interface throughout the day. Wind loading was isolated to the more northern aspects of this slope (photo). Evidence of previous wet loose slides were overserved across the valley on southern aspects. The near surface facets were found to be very weak (photo is of CT5 failure on this interface, column on the left with near surface facets visible to the right) but we were unable to get it to propagate. A few extra hits (6) on the CT column caused a collapse of the column at the depth hoar layer.
Region
Out of Advisory Area
Observer Name
Erich Schreier
Natural Avalanches on Wind-Loaded Slopes, Taylor Fork
Taylor Fork
Southern Madison
Code
SS-N-R1-D1
Elevation
9400
Aspect
NE
Latitude
44.97100
Longitude
-111.31000
Notes
Three natural avalanches in Sage Basin and two natural avalanches in Sunlight Basin failed on 3/28 and/ or 3/29 on heavily wind-loaded slopes. All were relatively small, but a good indicator of the hazard at higher elevations or larger terrain.
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
1
Problem Type
Wind-Drifted Snow
Slab Thickness
18.0 inches
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
Two natural avalanches in Sunlight Basin occurred on a heavily wind-loaded slope. Also, note the very large cornice overhanging the slope. Avoid getting on top of or underneath these large overhangs of snow as they can break unpredictably. Photo: GNFAC
Avalanche Details: Natural Avalanches on Wind-Loaded Slopes, Taylor Fork
Forecast link: GNFAC Avalanche Forecast for Fri Apr 2, 2021
Southern Madison, 2021-03-30
Forecast link: GNFAC Avalanche Forecast for Fri Apr 2, 2021
A small, natural avalanche in Sage Basin occurred on a heavily wind-loaded slope. Also, note the very large cornice overhanging the slope. Avoid getting on top of or underneath these large overhangs of snow as they can break unpredictably. Photo: GNFAC
Avalanche Details: Natural Avalanches on Wind-Loaded Slopes, Taylor Fork
Forecast link: GNFAC Avalanche Forecast for Fri Apr 2, 2021
Southern Madison, 2021-03-30
Forecast link: GNFAC Avalanche Forecast for Fri Apr 2, 2021