Student Research Would Improve High-Impact Flash Flood Warnings in Rural Va.

Originally published in the Morning Ag Clips

Written by Max Esterhuizen, Virginia Tech

March 10, 2026

BLACKSBURG, Va. — It was winter 2009. Snow blanketed southwest Virginia.

On Virginia Tech’s Blacksburg campus there was enough snow to cancel class — a rarity.

McKenzie Tate, now a senior in meteorology from Norton, Virginia, was glued to the television. She was enthralled by the impact nature could have on her home region, something she hadn’t seen before.

A loud crashing sound came from outside her window. Weighed down by the snow and ice, a tree branch crushed her swing set, demoralizing for a 5-year-old.

After the initial anger at Mother Nature wore off, fascination remained, along with a lifelong motivation to help people improve warnings for large-scale weather events.

Tate carried that passion for serving communities with her to Virginia Tech’s meteorology program, where she is working on a project to improve high-impact flash flood warnings in rural Virginia by studying the density of current National Oceanic and Atmospheric Administration (NOAA) rain gauges.

Over the past four years, the region has experienced multiple high-impact flooding events that caused widespread damage and loss of life. Yet the defining steep terrain in Appalachia also complicates how rainfall is measured and monitored.

These warnings require data – and NOAA rain gauges, with a few from the United States Geological Survey, have strict placement requirements. They need open, flat land with no nearby trees. In a region full of mountains, valleys, and forests, that’s difficult.

“There are very few NOAA rain gauges in the region,” said Tate, a recipient of the A.E. “Jim” Evans Scholarship. “For example, we estimated that Grundy, Virginia, is about 60 kilometers [37 miles] from the nearest NOAA rain gauge. What’s happening 60 kilometers away could be very different from what’s happening in a specific town surrounded by complex terrain.”

The team evaluated how well radar-based precipitation estimates perform in this complex landscape. During major storms, the National Weather Service relies heavily on radar-driven rainfall estimates. But in mountainous areas, radar beams can be partially blocked or distorted by terrain, increasing the likelihood of error, particularly in communities located far from radar sites.

By comparing national rain gauge records with NEXRAD radar data and Multi-Radar Multi-Sensor (MRMS) estimates, the researchers found that results are highly sensitive to the availability of ground-based observations. With fewer gauges available to correct radar-only estimates, errors can become more pronounced during short-duration, high-intensity storms, the type most likely to trigger flash flooding.

“In one case, we noticed a ‘blue bubble’ of lower precipitation around a station, surrounded by higher precipitation estimates,” said Tate, also a member of the Marching Virginians. “That suggested the density of stations affects how MRMS integrates observational data. MRMS uses radar and assimilates ground observations together. With fewer stations, the system has less ground data to refine its estimates, leading to generalization in areas farther from gauges.”

The findings highlight a broader challenge: Areas that are already vulnerable to flooding often have limited monitoring infrastructure. Expanding ground-based observation networks across Appalachia could improve rainfall estimates, strengthen warning systems, and help protect communities facing increasingly extreme precipitation events.

When doing background research for the study, Tate read in a 2011 study that central southern Appalachian region experiences some of the highest six-hour precipitation rates in the world.

“That makes it even more important to improve forecasting and communication,” Tate said.

Tate is working with Craig Ramseyer, associate professor in the Department of Geography, on the project.

“McKenzie’s research quantifies the spatial data inequity problems in far Southwest Virginia, specifically analyzing high temporal resolution rain gauges,” Ramseyer said. “These rain gauges are critically important for flood detection and measurement and yet, are sparsely available to forecasters making floods in the region hard to diagnose in real-time. McKenzie’s research serves as a critical building block for future funding proposals to install rain gauges in the towns and cities in Appalachia that are most in need of data for flood detection.”

Working on this project as an undergraduate clarified that Tate wants to focus on high-impact flood events in her career and steered her toward a meaningful career path.

“I love meteorology, but I care even more about helping people,” she said. “I volunteered with the meteorology club in Giles County after Hurricane Helene to assist with cleanup. These experiences reinforced that I want to combine science with communication, such as improving warnings and helping communities respond.”