Whiteout can happen at any elevation and is of three types: Clouds (including dense fog), snowfall, and a combination of both. Whiteouts can be localized and happen regardless of the weather forecast. Whiteouts vary in consistency, severity, and duration.
Mild whiteout: Ground, terrain features, and team are visible within 50–100 meters. Typically, cloud whiteouts are mild and allow visibility of the ground. The degree of forward visibility changes frequently enough to keep moving along the planned route.
Severe whiteout: Ground and sky are indistinguishable, team members are not visible beyond 5–10 meters. A combination of dense clouds and heavy snowfall creates the most intense and challenging form of whiteout. Your ability to distinguish the ground from the space around you diminishes, and you can feel dizzy and off balance. In extreme conditions, there is a loss of depth perception. Depending on severity and terrain, you may need to stop until it passes or even set up a temporary camp.
It might be expected that whiteouts would be a likely cause of hikers getting separated from the team or lost. Even though we have sometimes hiked full days in mild whiteouts, it has never resulted in lost hikers, separation, or prevented us from reaching our destination. That said, whiteouts are often a significant source of anxiety for inexperienced hikers. Care has to be taken to manage this anxiety and prevent irrational behavior, panic, and conflict within the team.
When there are signs that visibility may drop, do the following:
- Close up the gaps between team members.
- Account for all team members.
- Take into account any nearby hazards such as cornices, avalanche-prone slopes, and steep drops.
- If conditions become extreme or if it is getting dark, everyone should ready their headlamps for red mode to make head-counts easier.
- Experienced hikers need to stay near the less experienced.
- If moving in severe conditions, toss an object on a utility cord in front of you to determine slope angle and detect drop-offs.
Let us know your thoughts and suggestions
Have I overlooked anything? I’m always looking for new ways to improve safety. Please share your ideas, experiences, and challenges below. Your comments and questions are welcome.
2 replies on “Whiteouts”
I have been on hikes in the WMNH where leaders carry long cords to help navigate cairn to cairn above treeline. And orange flags to mark important trail points on a traverse to a summit. These trails are above treeline and often have ~6ft high rock cairns to mark the way. On the way out we clean the snow off the rock faces so they are darker and easier to see on the way back.
This is an interesting point and something that could be useful for some winter backpackers, depending on where they are going and the conditions. So thanks Geoff for bringing this up. I have considered using small flags to mark off hazards such as cornices and ice holes near our camps. For us, marking routes is a bit impractical because we are often hiking 8–10 miles (12–16 km) a day, and whiteouts are intermittent, and where they happen is unpredictable. We are often creating our routes and are the only backpackers in the area for the season. Each time we go out, we are in a different area, so marking a route in advance is not something we can do. Each winter, we do a series of different routes, mostly just once. In some areas, the snow accumulation would bury flags before anyone is likely to follow. There are, for example, about six areas near Mount Baker that we go into, and there is over 50+ feet (15–16 meters) of snow there every year. That said, there probably are situations when markers would be helpful if we had them.