Weather forecasting, climate studies and landslide awareness could improve soon in Tennessee.
State lawmakers have just proposed legislation to establish a statewide “mesonet,” which could ultimately be a network of ground-level weather stations in every county in Tennessee.
The bill also tasks the Tennessee Department of Environment and Conservation with collecting and publishing data on landslides and floods on a public map.
“This is a great first step to go ahead and arm ourselves with data to understand how significant the problem is,” said bill sponsor Rep. Jason Powell, D-Nashville.
Many Tennesseans have become familiar with flood risks in recent years, but landslides are a new, less visible phenomenon for some parts of the state because of climate change and poor development practices.
After an eight-inch rainfall in March 2021, a roughly 300-foot-wide landslide split the backyards of six homes in South Nashville. WPLN News interviewed the families impacted by the landslide last year. Powell, who is the representative for these families, says his motivation for the legislation was to prevent any more people from waking up to the same shock.
The research needed to understand and prepare for landslides, such as calculating the rainfall amounts needed to trigger landslides in different soil types, requires mesonet data.
“We’ve been flying blind not having that type of data,” said Tennessee state climatologist Andrew Joyner.
Mesonet stations are equipped with upwards of a dozen sensors, for parameters like rain rates, soil moisture and air pressure, that can supply continuous, nearly instantaneous data to local, state and federal agencies.
Farmers use this data to schedule irrigation. Scientists can design better climate studies. And utilities make more accurate forecasts of electric load.
“It’s really limitless,” Joyner said.
Mesonets can even save lives. The infrastructure gives forecasters more details, basically, to understand weather at the “mesoscale,” the meteorological term for about every 20 miles.
During a heavy rainstorm, for example, forecasters can tell just how quickly rain is falling, how likely flooding is and what type of warning to issue. During the December 2021 tornadoes, the Kentucky Mesonet was feeding data to the National Weather Service every three seconds, allowing forecasters to observe the sudden drops in air pressure.
This infrastructure would have helped forecasters understand the now infamous Waverly storm, a flood that killed 20 people. Instead, forecasters relied on radar and an airport weather station about 70 miles away. The highest rainfall amount during the storm — nearly 21 inches in the town of McEwen — was not confirmed until several months later.
“You can guess with radar, but it’s just a guess,” Joyner said.
Stations can also help the state save money across a variety of sectors, including agriculture, energy, emergency management and transportation. The Oklahoma Mesonet created an app to help peanut farmers avoid disease on their crops based on local air temperature and humidity conditions.
Since weather data affects virtually all aspects of society, Joyner thinks the state will be able to quickly recover the costs of the mesonet and then save more.
“It’s such a good return on investment for the state,” he said.
Joyner has been leading a mesonet working group for about a year with state agencies like the Tennessee Department of Environment and Conservation and the Tennessee Emergency Management Agency, both of which declined to comment on the proposed legislation. TEMA just hired a new head meteorologist, Megan Schargorodski, the former manager of the Kentucky Mesonet.
Joyner thinks the bill could complement the existing efforts to get a Tennessee mesonet.