6 Signs of Exposure

Where am I to go, now that I've gone too far? — Golden Earring

Let's talk about terrain selection for a few minutes. A few years ago I wrote a rather long article on terrain selection, which I followed up with another article that explained the statistical basis for the model. I don't think anyone would argue about the importance of terrain selection, but the simple model of evaluating slope angles isn't quite enough.

With that in mind, I'm going to write a simpler post that discusses the six universal signals of exposure. The benefits of the six universal signals of exposure is that they're easy to use ( regardless of experience ) and they can easily be integrated into trip planning. This means you can evaluate exposure before you set foot on the snow.

The Model
LOCALE. A model for analysing exposure that gives you holistic information about exposure to avalanches.

Criteria	Description
Line-Of-Sight	Is line-of-sight limited? Do local terrain features obstruct your line-of-sight to terrain above or below? Is your uphill view blocked by rocks or trees? Can you see all the terrain above and below or only some of it? Pay attention and double-check your decisions when line-of-sight is limited for any reason. Limitations to line-of-sight can reduce your reaction time to zero. ( I personally feel like this is one of the most important, and overlooked, elements of terrain selection. )
Open	Is the terrain open enough to produce small, medium, or large avalanches? Are there open breaks in the forest that allow snow to travel unobstructed to your location? How much open terrain is present and where is the open terrain relative to your location? Large quantities of snow can accumulate in open areas near mountain tops before an avalanche and in valley bottoms after an avalanche.
Confined	Is the terrain confined relative to the size or speed of an avalanche of any size? Could a large, fast-moving avalanche overrun the valley floor? Are you in a gully where escape from a small but fast-moving avalanche could prove impossible? Small avalanches form deep deposits in confined terrain, such as hollows or depressions, where snow can accumulate. Estimate your reaction time before something goes wrong and double-check your decisions if reaction time is short. Reaction time is a very important part of your margin of safety because it can tell you a lot about the true degree of exposure for where you plan to travel.
Accumulation	Has snow accumulated above or below? Avalanches often start where snow accumulates, and then run downhill where they deposit snow on the valley floor.
ObstacLes	Are there obstacles above or below? This includes cliffs, crevasses, rocks, and trees. Obstacles above may block your line-of-sight, inducing hazard blindness, and can cause traumatic injuries during any phase of an avalanche. On the other hand, obstacles can block or redirect flowing snow and may offer protection at your current location.
StEep	Is the terrain steeper than 30 degrees? Avalanches start and rapidly accelerate on steep terrain. Steep terrain produces fast-moving avalanches that can release above you and travel toward your location. If you trigger an avalanche on steep terrain, you may be unable to escape from the flowing snow. Steep terrain can limit your line-of-sight, and indicate locations suitable for sluffs, cornice drops, serac fall, or rock fall—all of which can start avalanches above or around you.