Mountain Safety

Yellowstone is home to some sick terrain, just watch out when it warms up, photos by Ralph Backstrom

Red Flags in reality is a Jones Avalanche awarness Month series detailing Live-From-The-Field stories about five of the most common signs of avalanche danger - The Red Flags. Next up we’ll learn about the dangerous effects of rapid warmingfrom an experience Ralph Backstorm had in Yellowsotne National Park.

A couple years back I went on a spring splitboard mission to Yellowstone National Park with Bryan Iguchi, Alex Yoder and Jeff Hawe. The first day of the trip we rode some smaller lines close to the trailhead. The snow had gotten really warm that afternoon so we bailed early hoping to come back the next morning and ride some of the bigger objectives we had scouted. On the way out we noticed small roller balls and point release slides but nothing too out of place for spring conditions. The spring snow just felt sticky and slow as usual.

So we left the park that night with the plan to come back early the next day. We never made it back in the park. Half-hour after we left the park gates a massive slide came down and buried the road to the park entrance! For more reasons than one, the slide caused by rapid warming was a trip ending red flag.” – Ralph Backstrom

Rapid Warming is one of the most prominent causes of snow instability and a major avalanche danger red flag. Warming causes instability in the snowpack due to a process known as ‘Creep Tension’. When the temperatures spike, the top layers in the snowpack go through a process of viscous deformation and become a separate layer that’s effected by gravity differently than the rest of the snow pack. The warm layers will ‘creep’ down the slope as they are pulled by gravity faster than the rest of the snowpack. This difference in motion between the surface and the base introduces tension.

This diagrma shows the effects of gravity on a snowpack, the red arrows are creep, the blue arrows are settlement and th eblack arrows are the movement of the entire snowpack and it’s base, known as glide, diagram by www.avalanche-center.org

When the warm surface layers start to ‘creep’, this added tension in the snowpack makes it easier to set off weaker under layers. Surface loads and stresses also penetrate deeper into the snowpack when the surface layers are warm making skier-triggered avalanches more likely.

Backstrom, Iguchi and the crew dig a snow pit in Yellowstone National Park.

Convex features are especially prone to ‘creep’ as they are already under tension. If you detect any signs of rapid warming such as roller balls, point release slides off rocks, trees shedding snow or an obvious temperature swing, convex slopes and other known avy paths should be carefully avoided. One of the other important things to remember about the rapid warming red flag is that it might be the only red flag you see that day. Unlike the other red flags that tend to appear simultaneously (new snow, winds, natural avalanches), rapid warming may be the only red flag observation you make before the avalanche danger increases significantly.

Rapid warm up caused an avalanche that buried the road into Yellowstone, Red Flags don’t get much more obvious.

Share Story
Published on
21 December 2012
6
Mar
Trip Reports
Hunza - Splitboarding In Pakistan With Julien ’Pica’ Herry
Story By Julien ’Pica’ Herry. Photos By Jeremy Bernard. Jones Ambassador Guide Julien ’Pica’ Herry shares the story behind Hunza, the new adventure film by Invade Media documenting the magnificent mountains and culture of the Hunza Valley in...
Julien ’Pica’ Herry
26
Feb
Meet The Team - Videos
Out Here Ep. 2 - Splitboarding In The Wasatch With Chris Coulter
Thrilled to debut the second episode of the OUT HERE video series! Made in partnership with Spark R&D, the OUT HERE series shares the backcountry snowboarding adventures of Jones x Spark R&D ambassadors as they explore the outer reaches...
Chris Coulter
22
Feb
2019 Splitboard Demos In the Eastern United States
Calling all shredders on the East Coast of the United States! Very excited to share some upcoming (and rare) opportunities to demo a splitboard in your neck of the woods. Join us at one of these events and learn what the thrill of earning your...
Seth Lightcap
25
Jan
Splitboard Skills Courses In Tahoe And The Tetons
You want to ride dream lines? What are you waiting for? Learn to splitboard! With a split in your quiver and the proper backcountry skills a lifetime of amazing riding experiences awaits you. Finding the right partners to teach you the protocols...
Brendan Burns, Iris Lazzareschi
7
Jan
Introducing The Ultra Mind Expander
It wasn’t a matter of if, it was a matter of when... Introducing the 2019 Ultra Mind Expander LTD, a new super charged version of the Mind Expander that Jeremy Jones and surf shaper Chis Christenson have been dreaming about for years. The Ultra...
Jeremy Jones, Jimmy Goodman
18
Dec
Meet The Team
From The Pipe To The Peaks - The Evolution Of Elena Hight
How do you top a fifteen year competitive freestyle snowboard career and a mantle full of the biggest trophies in the game? If you’re two-time US Olympic Halfpipe team member Elena Hight, the next chapter of your shred career starts with a long...