As mountain snow becomes perilous, forecasts are critical

NOAA and U.S. Forest Service partner to keep the public safe from avalanches


An avalanche occurs at an elevation of 10500 feet at Elk Point, UT in the Wasatch Mountain range.

An avalanche occurs at an elevation of 10,500 feet at Elk Point, Utah, in the Wasatch Mountain range.

(Photo: Bruce Tremper/U.S. Forest Service Utah Avalanche Center)

Are you a fan of snow sports? Each winter people venture into the mountainous back country for outdoor fun such as skiing, snowboarding, snow-shoeing, and snowmobiling. But as any adventurous skier or snowboarder knows, keeping informed by the latest weather and snow conditions is critical – especially where the potential for avalanches is high.

On average 28 people die in avalanches in the United States each year. It goes without saying that as the number of outdoor enthusiasts increases, so does the risk that more people will be hurt or killed in avalanches.

But this doesn’t have to be. NOAA’s National Weather Service partners with the U.S. Forest Service Avalanche Centers to help keep the number of fatalities as low as possible.

Bruce Tremper, director of the U.S. Forest Service Utah Avalanche Center, triggers a controlled avalanche while conducting field observations.

Bruce Tremper, director of the U.S. Forest Service Utah Avalanche Center, triggers a controlled avalanche while conducting field observations. Avalanche Center staff deliberately set off controlled avalanches to reduce the hazard avalanches pose to human life and property; they are conducted when no one is in the avalanche-prone area. Controlled avalanches can be started with explosives, artillery fire or by ski checking. Ski checking, done by a team of trained specialists, is performed by skiing along fracture lines high on the slope.

(Photo: Bruce Tremper/ U.S. Forest Service Utah Avalanche Center)

We know snow

National Weather Service meteorologists provide U.S. Forest Service avalanche forecasters with critical weather information daily: precipitation, new snow totals, temperature, wind, snow water equivalent, cloud cover and solar radiation data. Avalanche forecasters combine this key weather data with their own knowledge of terrain and snowpack to create a more comprehensive avalanche forecast. Avalanche forecasters then issue warnings and avalanche danger ratings on a daily basis. If snowpack data is unavailable, avalanche potential can be estimated based on weather information alone.

“The National Weather Service role in avalanche forecasting is multifaceted,” says Larry Dunn, meteorologist in charge of the Weather Forecast Office in Salt Lake City, Utah. “National Weather Service forecasters initially provide avalanche forecasters with weather data for their forecasts. Then we help disseminate those forecasts to the public and media via weather.gov and NOAA Weather Radio.”

Bruce Tremper conducts a field observation of a ski slope prior to creating his avalanche forecast.

Bruce Tremper conducts a field observation of a ski slope prior to composing his avalanche forecast.

(Photo: Bruce Tremper/U.S. Forest Service Utah Avalanche Center)

Warnings and avalanche danger ratings

Avalanche danger falls into five warning categories:

Currently, avalanche forecasters do not have computer models that forecast avalanches with any degree of accuracy. Good weather information from the National Weather Service and each avalanche forecaster’s experience and knowledge are crucial in composing each daily forecast. Field-based observations on the mountain are essential to creating an informed forecast.

“The partnership between the National Weather Service and Avalanche Centers is extremely valuable and benefits both agencies, but more specifically can save the lives of outdoor enthusiasts,” says Bruce Tremper, director of the U.S. Forest Service Utah Avalanche Center.

Before heading into the backcountry, Tremper suggests you consult both the National Weather Service weather forecast and the avalanche forecast for your mountain area. He also recommends using proper safety gear and taking an avalanche safety class.
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Learn more about avalanches and forecasting by visiting the Colorado Avalanche Information Center and U.S. Forest Service National Avalanche Center  webpages. 

Posted Feb. 11, 2014 NOAA logo.