19-20

Two skiers skinning up the North Bowl Road narrowly missed getting hit by a pair of avalanches running well into North Bowl. Remember the North Bowl Road crosses through serious avalanche terrain and is not a good up track. Photo: K Kempt

Bridger Range, 2020-04-16

Natural and skier triggered loose snow slides at Bridger

Bridger Bowl
Bridger Range
Code
L-AS-R1-D1.5
Elevation
8000
Aspect Range
E-S
Latitude
45.81560
Longitude
-110.92300
Notes

Skiers reported many loose snow avalanches after noon.

"Small slide off of banzai into a chute fan. Natural release. Pic before slide 12:43 of slide 12:51"

"[In north bowl] Around one o’clock. Right before the two skiers skinned by."

 
Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Skier
R size
1
D size
1.5
Problem Type
New Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

New Snow Avalanches Bridger Range

Bridger Bowl
Bridger Range
Code
SS-AS-R2-D1.5-S
Aspect Range
SE-NE
Latitude
45.81560
Longitude
-110.92300
Notes

From IG "Natural avalanche in the Apron. Ran Full path"

From Email, "We just did one run down Ptarmigan.  Winds were cranking out of the north from about Midway Bridger on higher.  Over on the north side of Bronco, there were some wind drifts that were super sensitive and were cracking and sliding into the skin tr track asily. While skiing the snow felt pretty upside down, similar to what we were seeing on the skin tra track Did a ski ski cut I came up to that first rollover that is often rocky early season and triggered a small avalanche.  It cracked easily and slid, but with the fairly gentle slope angles right below that rollover it stopped pretty quickly.  We only did that one run and with the snow as sensitive as it was I wouldn’t have wanted to go up to the ridge today."

Observed debris from 3 new snow avalanches from the top of Powder Park Lift at Bridger Bowl. Two ran from the Dick's/ Bradley's Rib area across the North Bowl Road and well into North Bowl. One slide on the south edge of Baby Bear came through the trees and stopped 100' above Powder Park Lift. 

 

Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
2
D size
1.5
Bed Surface
S - Avalanche released within new snow
Problem Type
New Snow
Slab Thickness
10.0 inches
Weak Layer Grain type
Precipitation Particles
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

GNFAC Avalanche Forecast for Wed Apr 15, 2020

Snowpack and Avalanche Discussion

<p>There is a good bit of new snow this morning around Bozeman and Big Sky and more is on its way today. Expect the new snow to be unstable, especially if snowfall rates are intense. As the storm started yesterday the new snow was already reactive. Skiers at Bridger unintentionally triggered a slide that broke 16” deep, under last weekend’s new snow, and ran past 8 lift towers on the Schlasman’s lift (~1,000 vertical ft) (<strong><a href="https://www.mtavalanche.com/images/20/debris-schlasmans-lift-towers">ph…;). Skiers also got dramatic shooting cracks and found the new snow unstable near the Bridger Ridge and in Beehive Basin (<strong><a href="https://www.mtavalanche.com/images/20/shooting-cracks-bridger">photo</a…;). The more new snow that you find in an area today the more dangerous conditions will be. In addition, west winds have drifted the new snow into much deeper drifts near ridgelines. Watch out for and avoid these drifts. With a shift to northeast winds overnight, be on the lookout for drifts in unusual places tomorrow.</p>

<p>Compounding our concerns with the new snow is the fact that there are still weak layers in the upper snowpack that remain reactive. Over the last week we’ve gotten multiple reports of unstable test results on weak layers (surface hoar and facets) buried 1-3’ deep. An avalanche breaking on these layers will be much larger than a slide confined to the new snow.</p>

<p>When the sun breaks through the clouds (either tomorrow or Friday), the snow surface will get wet and instability will spike again. It won’t take long for the strong mid-April sun to turn the new snow into unstable glop. Avoid steep terrain as this transition occurs.</p>

<p><strong>A special note if you are planning on riding steep terrain at Bridger Bowl</strong> - remember that the ski area has been closed for a month, there has been no avalanche mitigation, and a backcountry snowpack exists. Don’t let familiarity lull you into complacency in what is now serious uncontrolled avalanche terrain. Tone it down and dial it back until the new snow settles.</p>

<p>Please continue to send us your observations. You can fill out an observation form, email us (mtavalanche@gmail.com), leave a VM at 406-587-6984, or Instagram (#gnfacobs). We greatly appreciate your support.</p>

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Give Big Gallatin Valley is April 30th - May 1st. The Friends of the Avalanche Center are participating again this year and we’d really appreciate your support! Thank you.