Science of snow | Forecasting avalanche conditions

Photos courtesy Sierra Avalanche Center

“Know before you go” is the mantra of the Sierra Avalanche Center (SAC), an important resource for the back-country community. The organization, started in 2005, monitors the region’s back country providing invaluable daily reports on avalanche safety and conditions.
“The goal of our organization is to bring awareness of avalanche conditions to the community, create more community interaction and offer more education. Avalanche centers are a relatively new phenomenon,” says Holly Yocum, SAC board president.
The nonprofit works in partnership with the U.S. Forest Service forecasters and it relies on donations to provide forecasts every day of the season.

“If we didn’t do this, there’d only be three reports a week. With the additional support we can have forecasts seven days a week,” Yocum says.

“Tracks in the snow are not necessarily a sign of intelligent life. You don’t know what went into the thought process of that person. Was it the first snowfall? What was their mental decision making? Tracks are not an indicator of traveling well.”
– Brandon Schwartz, forecaster

There are three Forest Service full-time forecasters and two part-time Sierra Avalanche Center observers that operate in five national forests: Mt. Rose Wilderness, Humboldt-Toiyabe National Forest, Tahoe National Forest and Eldorado National Forest, covering an immense amount of terrain in California and Nevada. Forecasters need to be fit and strong to cover this amount of territory. Each day they must determine what areas to go to that will be representative of snowpack.

Brandon Schwartz is one of three local forecasters who starts the day at 4:30 a.m. He and his colleagues spend 1½ to 2 hours each morning building the avalanche advisory that is published by 7 a.m. The forecasters take time each day to do office work and then go back out into the field to validate their advisory for that day and gather data to build the next day’s advisory.

“This information is a starting point for decision making for people,” says Schwartz.
Forecasters monitor the snowpack on a daily basis, follow weather reports and evaluate wind slabs and conditions, as well as gauge nine potential avalanche problems.
When heading out into the back country there are many things to consider.

“Tracks in the snow are not necessarily a sign of intelligent life,” says Schwartz. “You don’t know what went into the thought process of that person. Was it the first snowfall? What was their mental decision making? Tracks are not an indictor of traveling well.”

Yocum agrees, “Following a ski track that has already been tracked out might be easier to follow but does not mean it is safe for you. You don’t know what that person’s skill level was or how the snow was set up when he or she skied the area. It is important to step back and look at different terrain that might be more difficult, but is important to consider.”
Schwartz explains that although people say they’ve never seen a slide in a certain area, it doesn’t mean that aspect will never slide. There are many factors that go into a determination. This kind of thinking is more about luck and less about understanding terrain and conditions. It only takes one time for an avalanche to occur and one can end up in harm’s way.

The Sierra Avalanche Center Web site provides daily forecasts, avalanche advisories and observations. There is also a resource and education section for training and events. A compelling 15-minute video on the site is designed for people new to the back country, which offers information about what you need to do before going into the back country and highlights the hazards and dangers of avalanches.

There is also a place on the site for the public to comment on what they encountered while in the back country.

“We appreciate when people submit information that not only helps the forecasters but also helps people heading out into the back country, informing them of where a slide or incident might have occurred,” says Yocum.

Don Triplat, executive director of SAC, has been skiing in the back country for the last 24 years.

“When I started out back-country skiing, I went out with people who had a lot of experience. They had the gear and could shepherd you through the terrain. It’s important to go with safe, responsible friends until you start to learn your way. There are lots of people recreating in the back country and more considerable danger. We need to be aware of what’s going on.”
He also explains that the target population with the biggest issue are males, ages 18 to 24. “They are the No. 1 accident victims and often have poor decision-making skills,” says Triplat.

Be prepared

Get the gear | Take a beacon, shovel, probe, avalanche bag and backpack. “You only have 10 minutes for survival if you are buried and you must rely on your partner or companions,” says Schwartz.

Get training | Take courses and become educated. There are four levels of training and many courses to help you learn and read back-country terrain.

Get the forecast | Read the daily avalanche advisory and forecast. “This is a starting point to make your plans,” says Schwartz.

Get the picture | Look for recent avalanche activity, instability, shooting cracks or collapsing snow pack. It is imperative to take into consideration new snow, wind slab, rain and rapid warming.

Get out of harm’s way | Avoid steep slopes. Don’t congregate under a steep slope. Travel down the hill one at a time.

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