BOONE—Accurately forecasting snowfall can be a hit or miss proposition in North Carolina’s mountains as residents and visitors can attest.
Professors from Appalachian State University, UNC Asheville and N.C. State University hope to change that by collecting a range of data to refine computer models used by weather forecasters to predict snowfall.
The project is funded by an $84,740 grant from the UNC General Administration’s Competitive Research Fund.
Baker Perry, an adjunct assistant professor in Appalachian’s Department of Geography and Planning, is the lead researcher for the project. He will be assisted by Doug Miller from UNC Asheville and Sandra Yuter from N.C. State University.
The problem with creating accurate forecasts lies in the diverse mountain topography, Perry explained.
“It’s very challenging to forecast snowfall because the spatial variability is so pronounced here in the mountains,” he said. In Western North Carolina, elevations range from 1,000 to 6,684 feet.
“Computer forecast models don’t fully account for the effects of mountain topography,” Perry said.
The lack of weather observations and data collection in the mountains is another impediment to developing accurate forecasts, Miller said. “When we talk about an area that covers peaks and valleys, there are a lot of microclimates within a weather event that we can’t even observe,” he said. “We can’t forecast something that we can’t observe. That’s why the forecast process is so difficult.”
Another challenge is obtaining accurate temperature readings at the different levels of the atmosphere. “A lot of times the atmosphere is very close to freezing. Just a half degree difference in temperature makes all the difference in whether there will be a big snow, a major sleet storm, a freezing rain event or just rain,” Perry said.
Perry, Miller and Yuter have installed weather instruments at the base and top of Poga Mountain in Avery County (pronounced as Pogey Mountain by most residents).
The instrumentation includes a vertically pointing radar to measure the intensity and fall speed of precipitation at different levels of the atmosphere; a laser-equipped instrument that measures particle size and speed; and a gauge that measures liquid of solid precipitation.
A series of weather balloons will be released during snow storms to collect temperatures, relative humidity, and wind speed and direction at different levels of the atmosphere. Snow depth and the snow water equivalent will also be measured at the research site as well as across the region by volunteers who are part of the Community Collaborative Rain, Hail and Snow Network.
“There is essentially no data from this region on snow density, so that’s one of the things we are really focusing on,” Perry said. Current weather forecasting models tell how much liquid will be generated when snow or frozen precipitation is melted. “It’s the forecaster’s job to make some assumptions of what the snow-to-liquid ratio will be to come up with a snowfall forecast,” he said.
The data will be maintained on a Web site that will be used by researchers who will compare real-time weather data with predicted by existing computer models.
Miller’s work during the past year will help the researchers focus on what he calls “a list of suspects” –variables such as wind speed and temperature that create the region’s snowfall events.
“Being able to understand the different aspects of what we call weather is at the core of this project,” Miller said. “We believe there are some things that aren’t well understood in terms of the basic science.”
Undergraduate students from each university will assist with the project.
“For undergraduates, there is no better way to understand things then to get your hands dirty and in this case it’s to actually be involved in collecting, analyzing and displaying the data,” Miller said. “The experience will give them a good overall perspective on what we rely on ultimately to make our weather forecasts and it will give them a great foundation to help them as future weather forecasters or as graduate students.”
The project has been endorsed by officials with the National Oceanic and Atmospheric Administration, the State Climate Office of North Carolina, the N.C. Department of Transportation, and area ski slopes and tourist attractions.
“This is a region where terrain influences are complex, radar coverage is rather poor, real time ground reports are relatively sparse and impacts from snowfall are significant for the economy due to tourism,” Stephen J. Keighton with the National Weather Service in Blacksburg, Va., wrote in a letter of support.
Economic impacts related to transportation access and accurate snowfall predictions are pretty substantial for northwest North Carolina, said Crea Morton, president of Grandfather Mountain.
“The ability to accurately measure, study and predict precipitation is of great importance. This affects not only the tourism and other industries vital to the region, but, more significantly, the ability for Department of Transportation, business and citizens to forecast and react to potentially dangerous weather.”
(This story was written and published by ASU News and sent to us by Baker Perry, who is involved with the project)