Episode 73 | Avalanche Awareness for Backpackers

[Backpacking Light]

Companion forum thread to: Episode 73 | Avalanche Awareness for Backpackers

In this episode of the Backpacking Light Podcast, you’re going to learn about avalanche awareness in the context of winter hiking, snowshoeing, and ski touring.

[Ryan Jordan]

I’m curious to learn what others take for avalanche safety gear, especially backpacking near the treeline where the risk starts to elevate vs. staying below the treeline the whole trip.

[Philip Tschersich]

Avoiding terrain capable of producing an avalanche weighs nothing. Understanding weather, snowpack, terrain, and human factors that lead to avy hazards weighs nothing.

But if you need to expose yourself to avy hazards, anything short of carrying a transceiver, probe, and shovel (and being darn handy with them) is not being responsible. That goes for you and everyone in your group. Pieps makes a very small and light transceiver (Micro BC), BCA makes a very light carbon probe (Stealth 260), and Arva makes a very light avy shovel (Ultra). I would only resort to such light gear if avy exposure was truly minimal and yet unavoidable.

If you are going solo you can skip all that stuff because no one is there to help you and you won’t need to assist anyone else. If solo, wearing a transceiver could be considered polite towards would-be SAR resources because it speeds up body recovery immensely.

[YoPrawn]

When solo, I stay away from avy terrain unless the snow is beyond obviously settled or iced up.

When with others, we stagger our walking distances to limit chance of one slide taking out everyone at once. Limit the number of people getting buried and increase number of rescuers.

Tree wells might not be such a big deal out here on the west coast? I’ve fallen into so many tree wells over my life, I don’t think I could even count them all. Maybe like 30+ times? Never got stuck once either skiing or snowboarding. Might have something to do with our tree types and snow firmness. We don’t get the uber dumps of champagne powder you guys in the Rockies get. Panicking probably makes it a lot harder to get out. I never knew they were dangerous growing up, and though they were actually fun to fall into while tree riding. LOL

Also, I ASSUME EVERYTHING CAN TURN INTO AN AVALANCHE! Even the smallest section of 35 degree slope I am traversing with only a 40 foot drop into a tree stand, might not look dangerous, but when a thick slab comes loose, it will bury you easily, or pummel you through the trees.

There was a man skiing a closed ski hill with his wife and kid a few years ago. Ski area was closed due to extreme snowfall and dangers. The guy took a little corner shortcut on a catback trail and was killed by a tiny avalanche just large enough to bury him. Tragic.

I also never go into any avalanche area with people I know are “DRIVEN” people who will ignore all signs in their pursuit of a goal. If I raise red flags about conditions and people ignore me, then I no longer do such things with those people. Driven stupidity is a major factor in snow deaths.

[YoPrawn]

Oh, and another thing not many people think of, is the risk of falling rock in winter, which is worse when a bad rock face freezes and thaws a number of times, letting rock come loose. Even if the snow looks solid, the rock above might have a higher chance of coming down if there is a melt and freeze cycle. This is pretty common here in the Olympic Mountains due to the rotten rock everywhere.

[Chad Lorenz]

I think an under appreciated hazard is overhead hazard, particularly in steep locations, such as the Rees-Dart loop in NZ and others. A few places in the PNW come to mind. It’s not enough to just avoid avalanche terrain, you also need to know what is above you and how it will react to the current weather patterns. Big terrain = big late season avalanche cycles.

[Eric Blumensaadt]

As a former alpine ski patroller in an avalanche-prone resort where a 105 mm Howitzer is used routinely all patrollers had to attend and pass the Avalanche 1 course, practice line probing with poles and finding and digging out a buried avalanche beacon in the newer “rotating shovelers” pattern with a V pattern of excavation.

If you backpack in avalanche danger areas, aside from Avalanche 1 training, you need:

1.)avy beacons (all turned to “transmit”) 2.)collapsable shovels  3.)probe poles/convertible hiking poles

4.)snow study kit (one per group)  5.)SATELLITE RESCUE BEACONS (several, in case one gets buried with a hiker)

Sounds like a lot of “bother” – until you need all of this training and gear, then it’s life saving.

BTW, having a woman in a hiking/skiing group seems to limit the “macho quotient” of a group where otherwise prudent people in an all male group may be quiet when the more macho men literally intimidate them into taking a risky route. MORAL: Take a few women in your group into avy terrain.

 

 

[Bryan Bihlmaier]

Another passive trigger to watch out for, especially when backpacking in early spring, is warming of the snowpack due to sun exposure (on solar aspects) and/or warm air temps. Loose wet slides, while slower moving than large slab avalanches, can be very damaging and injure or bury you just as easily. They are still faster than you are!
Always be aware of what’s above you (slopes that could slide, draws that could direct slides) and below you (gullies where you would be buried deeper, trees or boulder fields, cliffs, rivers). And especially watch for signs of wet snow instability: “roller balls” or pinwheels of snow, small slides from point-releases such as rocks or trees. If these are happening around you, immediately take the safest exit out of that terrain!
I’ve had a wet slide come down right next to me while I was transitioning my BC skis below a stand of trees, because I ignored the signs. Very scary and a rude awakening!

[Bryan Bihlmaier]

For runout zones, you should discuss what is called “alpha angle”.  It’s basically the angle, from horizontal, between where you are standing/ walking/ camping, and possible avalanche start zones above you (corniced ridge, change in slope angle, etc).  It’s a measure of how far an avalanche could potentially run from that slide path before stopping.
Unfortunately, the critical alpha angle is different for every region, because the snow types are different. It’s important to know what the critical alpha angle is for the region you are in, so you can be sure to stay out of runout zones.
For example, we recently had a very large avalanche here in Utah where I live that traveled 12.8° from the initiation point.

[Ryan Jordan]

Bryan – which avalanche was that? A 12.8° runout angle is ridiculous!

[Scott Roach]

Bryan, that sounds like the big slide on Gobblers know recently which ran an extraordinarily long distance on low angle terrain after propagating on steeper terrain. Scary stuff. Luckily it wasn’t human triggered and no one was there.

I’d say the 1st most important thing to learn is terrain avoidance. Learning safe corridors to travel and how to spot terrain traps is crucial 1st steps. Visability is key here and knowing what is above you as well.  proper avalanche search techniques are equally important but with terrain aviodance, someone with limited avalanche experience could still get out and enjoy winter travel. Once some knowledge is gained thru avalanche courses on evaluating snow should one consider going into avalanche terrain.

Ryan, to your point of staying below tree line, I would say that is a complicated issue. Lots of avalanches have started and/or run thru heavily tree’d areas.

[Ryan Jordan]

to your point of staying below tree line, I would say that is a complicated issue. Lots of avalanches have started and/or run thru heavily tree’d areas

For sure. Lots of heterogeneous tree cover and different degrees to which trees can stabilize slopes out there.

[Bryan Bihlmaier]

Ryan – sorry, I honestly mis-remembered the alpha angle on that slide and couldn’t find it to look it up. It was actually 17.2deg. 6-8’ deep, so pretty scary. Here’s the write-up.
https://utahavalanchecenter.org/avalanche/73452

Thank you for covering this concept in the related Member Q&A.

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