How to access and interpret the avalanche forecast.
By Rob Coppolillo
Who needs another thing to worry about when going out skiing? I know, it seems like there are icy highways, forgotten beacons, sketchy partners, and any number of stresses out there. I’m not here to add another to your list. Rather, by helping to interpret “avalanche problems,” I hope to make backcountry riding and sliding more straightforward.
“Get the Forecast, Get the Picture”
Several years ago English-speaking avalanche educators, researchers, and forecasters got together to try and standardize the lingo they use for describing avalanche hazard to the public. They were hoping to make “getting the forecast” and “getting the picture” easier for us.
You understand the need, too: one guy coming out of the hills says, “Yo, that was some funky windjack up there!” while the next guy might say, “I had to skicut that pillow at the start and it was knee deep!”
So, does that mean the skiing was good or bad? Dangerous or safe? Did they see any wind-affected snow? By trying to standardize our vocabulary, it cuts down on misunderstandings, between people talking about avalanche danger and between zones you might visit.
In 2012 the avalanche community from New Zealand to Canada and the United States got together and agreed on nine categories of “avalanche problems” to be described in avalanche bulletins. We were all starting to speak the same language when we “got the forecast” and “got the picture.”
This last point is critical: now you can bop up to Valdez on your G-Star, back down to Revy, then snag some El Nino pow at Taos, and no matter where you go you’ll see the same language and definitions when dealing with the local avalanche bulletin. Makes staying safer easier, eh?
Problem(s) of the Day
Forecasters and educators recognized that different avalanches behaved in different ways…pretty simple. Think about it in these terms, though: what’s more dangerous, your drunk Uncle Bob playing with a pellet gun at Thanksgiving dinner or doing stunts with a .44 magnum? Right—you’d probably rather he quit playing with both of them, but it’s a way bigger deal if the .44 goes off. Don’t ask me how I know this.
Brian Lazar and Ethan Greene (of the Colorado Avalanche Information Center) and Karl Birkeland (of the National Avalanche Center) were instrumental in developing the nine “problems” to be used in avy bulletins.
In a 2012 article they wrote, “The flavor of the avalanches we expect to encounter can be more influential in our risk-management practices than a given danger or stability rating.”
What they’re saying is that one avalanche might be a pellet gun, while another is a .44. For example, “Storm slabs” (one of the nine problems) tend to be far less deadly and destructive than “Deep Persistent Slabs” (another of them). This is not to say you can’t get nuked by a storm slab—six inches of sliding snow can easily push you off a cliff, for example. In general, though, Deep Persistent Slabs tend to be deadlier, harder to predict, and larger than storm slabs which are usually easier to predict and tend to heal more quickly.
So all the forecasters are doing for us is letting us know if we’re playing with a .44 or a pellet gun. You don’t want to get shot by either, for sure, but at least you know one will kill you deader than Uncle Bob and you might survive the other.
Great, but what do we do with this info?
What Lazar, Greene, Birkeland and others also realized is that not only are avalanches different, but our strategies to avoid them are, too.
For example, the definition of Storm Slabs describes the problem: “…they typically last a few hours or days…Storm Slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.”
The definition then continues to give us a specific risk-mitigation strategy.
It says, “You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm Slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.”
Focus your tour plan and mitigation strategies on what to do, rather than what not to do. You might “wait out” a Storm Slab, giving it a day to stabilize or sluff. A Deep-Persistent Slab, though, requires a more disciplined approach. This might mean sticking to less-than-30-degree terrain for the remainder of the season, at least on certain aspects. They’re called persistent for a reason, folks! To give another example, a Persistent Slab problem, on the other hand, might require a wider berth—literally, more physical distance between you and steep terrain or a start zone—than a Wind Slab.
So, each day your local avalanche bulletin delivers the forecast, describes the avalanche problems you’re facing—it helps you “get the picture.” With the problem you get an idea of how big, how destructive, and where these avalanches might occur, and you get specific ideas of how to lessen your exposure to them. All this information helps you to plan exactly how you’re going to avoid an avalanche.
Once you have the forecast and the picture, you can get down to planning specifically how to “get out of harm’s way,” or minimize your exposure to avalanches and minimize your time in the terrain associated with that day’s potential avalanches.
From our Storm Slab problem above, it highlights “slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the slide” as the most dangerous. Now you go to your topo map, Google Earth, your run atlas, and CalTopo.com to identify steeper slopes with terrain traps present. Avoid them!
You’ve gone from the problem, to the risk-mitigation strategy, to planning exactly where you will and won’t go. It’ll take some practice at first, but incorporate avalanche problems, and planning for them, into your process and you’ll be safer in no time.
A Repeatable Process
The folks who study risky jobs and sketchball environments tell us that the way to stay safe in such situations is to have a “repeatable process” when planning. This means a process you and your ski team can perform each and every time you go out. Does it have to take an hour? Probably not. Divide up duties and you can put together a safe, reasonable tour (with options for hero lines, safer options, and bail-outs, too) with just 15-20 minutes of work.
Research shows this is the best approach to working and playing in dangerous terrain. Get your process dialed!
Where to Get the Info
You’re psyched and ready to play along—Get the Forecast, Get the Picture, Get Out of Harm’s Way.
If you don’t already know where to find your local bulletin, then do a little research. Drop by avalanche.org and you’ll find a list of every avy center in the US and links to international sites as well. There are also several smartphone apps which will link you to avalanche centers all over the world. Look around and you’ll find tons of info.
Most avalanche centers have easy links to each avalanche problem, which will give you the definition and the risk-mitigation strategy. If you read the forecasters’ blogs, you can get even more detail and information.
Start reading your local avalanche bulletin every day and you’ll soon know the characteristics and mitigation strategies for each of the avalanche problems. You’ll be safer, a better tour-planner, and you’ll be one step closer to becoming a True Mountain Jedi. And everybody loves a Jedi, yo.
Rob Coppolillo is an IFMGA-licensed mountain guide and co-founder of Vetta Mountain Guides, based in Boulder, Colorado.