PLYMOUTH — Ever get nervous about driving in winter weather? Wonder if those dark clouds overhead will bring flurries or perhaps something worse, like freezing rain? It’s a common concern, and a legitimate public safety issue–New Hampshire citizens need accurate forecasts, particularly when winter weather leads to hazardous road conditions.
A new experiment underway on the campus of Plymouth State University may help forecasting winter storms and hazardous driving conditions. According to PSU Associate Professor of Meteorology Sam Miller, the Snow Level Radar (SLR) experiment is a joint effort between Plymouth State’s meteorology program and the National Oceanic and Atmospheric Administration (NOAA), a US federal agency that studies the conditions of the oceans and the atmosphere.
“We often hear forecasters use the phrase, ‘wintry mix,’ which means it’s going to be rain, snow, sleet or a combination of those things. The problem is, over a distance of just a few miles there could be freezing rain, which can be very dangerous, or ice pellets, which are annoying but don’t create the same massive hazard to traffic that freezing rain creates,” Miller said.
For the next two years, the trailer-mounted SLR unit will be parked adjacent to Grafton Hall, a student residential facility on the PSU campus. The unit consists of two upright cylinders containing radar and a computer system that collects the radar data. Miller says the unit sends out a low-power microwave signal to determine what’s happening in the sky.
“The radar pulse goes up vertically, bounces off whatever precipitation happens to be falling, and then goes back to the unit and into a receiver box. The receiver feeds the information into a computer which then identifies how far the pulse went and what it bounced off of, whether it was liquid precipitation, if it was frozen, like snow, or if was it something that was melting,” noted Miller. “The SLR determines where melting occurs because snow falls from colder air into warmer air. The instrument detects the level in the atmosphere where the frozen precipitation melts and changes into rain,” noted Miller.
“It’s a state-of-the-art instrument that provides a different way to look at the atmosphere,” said Paul Johnston, a systems engineer at NOAA. “There are precipitation problems on the East Coast and with units like the SLR, we’re starting to learn how to address those issues.”
Brendon Hoch, an Information Technologist with PSU’s Department of Atmospheric Science and Chemistry, said the data could eventually lead to specific forecasts for a variety of people, such as motorists, ski area snowmakers and public safety officials.
“We hope to be able to determine whether we’re going to get a light, fluffy powdery snow or a wet heavy snow, and how much will accumulate,” he said. “Light snow will accumulate much deeper in depth, and that can affect plow operations for state highways.”
Michael Wessler, a junior meteorology major from Plymouth, added the SLR has been used almost exclusively on the West Coast. That PSU is now hosting the experiment is a boon to students who will be able to interact with this cutting-edge technology and equipment.
“It’s getting into an area of forecasting and meteorology that isn’t clearly defined or entirely understood,” Wessler said. “It’s exciting because we’re analyzing newer data and using new technology in a location that hasn’t been studied before.”
Hoch said the only cost to PSU for the SLR installation is a modest amount of electricity; he also asserts there is enormous value for the University both educationally and scientifically.
“It’s win-win. NOAA has a new location in which to test their instrument and PSU’s students and faculty benefit from access to this important data,” Hoch said.
The science of meteorology and weather forecasting has evolved dramatically over the past 30 years, primarily due to satellite and computer technology. Miller believes there is much more to learn and that’s what PSU hopes to accomplish with the SLR project.
“We’re taking theory and using it to improve what operational meteorologists do,” said Miller. “The reason we all do this is, ultimately, to make better weather forecasts.”