Editor’s note: This past weekend, an unprecedented tornadic storm crossed through multiple southern states, causing catastrophic damage and loss-of-life across the region, including at least 70 deaths in Kentucky alone. The impact of this tornado—or potentially series of tornadoes—on local communities cannot be overstated. As scientists, members of our meteorology team are working to better understand the data and insights as new information is uncovered. While the National Weather Service continues to perform official damage assessments on the ground, this article provides some early context for our readers, particularly insurance carriers, to help make sense of this devastating event.


Analyzing the Quad-State Tornado with weather forensics

Athenium’s tornadic storm tracker uses real-time Multi-Radar Multi-Sensor (MRMS) and dual-polarization Doppler radar (from the National Weather Service) to pinpoint rotation maxima (the center of rotation) for active tornadic storms in near-real-time. These areas indicating active tornadic storms are then analyzed for debris signatures. This enables our solution to provide critical weather forensics data to insurance carriers in less than two hours after a tornado occurs. These insights help inform disaster response efforts and allow insurers to deploy boots on the ground quickly and effectively.

During the Quad-State Tornado(es), debris was lofted up to 30,000 feet in the air, which is one of the highest debris signatures ever recorded, indicating an updraft capable of supporting significant (EF2+) to violent (EF4+) tornadoes. Damage signals were present in radar data as the storm approached Mayfield, KY, Princeton, KY, and Earlington to Bremen, KY. This continuous track of tornadic circulation recorded by radar throughout the storm lifecycle may indicate the longest tornado ever recorded, exceeding the length of the Tri-State Tornado that crossed from Missouri to Indiana in 1925.

Mayfield Madisonville Kentucky tornado EF2+ damage map

Athenium’s weather forensics shows significant debris near Mayfield, KY & EF2+ damage signatures near Madisonville.

The tornado damage assessment process

As of Monday, December 13, expert teams from NOAA are closely examining the tornado path, with wind damage experts analyzing the destruction to determine official damage ratings. These insights will help uncover whether this was a single, continuous tornado or a series of tornadoes across the region. However, this process is time-consuming – survey teams arrived on Monday, December 13, and it may take a week (or more) to complete the full assessment.

For those looking to better understand this event and its potential impacts on communities, property and infrastructure, the real-time event data is now available in our forensics tool, Dexter. Once the official surveys from the National Weather Service are complete, these will also be available in the dashboard by clicking the “Display EF-Scale Damage Rating” link at the bottom of the left-hand panel.

This data first entered our web dashboard at 8:40 PM Central Time on December 10, 2021, with hourly updates for the five hours that the supercell moved across Arkansas, Missouri and Tennessee. The full tornado was resolved by 1:40 AM Central Time on December 11, 2021. Since that time, the tornado forensics data has been quality-checked by our team to ensure it is ready for consumption at scale by our clients.

If you or your insureds were impacted by this event, please reach out for details on how to access our forensics data by emailing info@athenium.com.

To learn more about our weather forensics solution for insurance carriers, please visit the Dexter page here.

On the horizon

On December 11, 2021, a storm chaser near Jonesboro, Arkansas snapped a photo of two tornadoes on the horizon. This phenomenon often occurs in tornadic supercellular thunderstorms as the atmospheric circulation for one storm dissipates and reforms further along the direction of storm motion. Athenium’s tornadic storm tracker (found in our weather forensics solution, Dexter) documented this slight “recycling” of the supercell, with the tornado track splitting across Interstate 555 southeast of Jonesboro while still showing two different rotation signals, at around 7 p.m. Central Time.

After this recycling event, however, the tornadic storm had a continuous path, crossing through parts of Arkansas, Missouri, Tennessee and Kentucky. This data, along with anecdotal storm chaser analysis, suggests that a single tornado could have remained on the ground for nearly 240 miles, with several observed tornado reports at various points along its path. If that proves to be the case, it would make the Quad-State Tornado a true outlier, with just a 1 in 10,000+ probability. In addition to the human-observed tornado observations, multiple radar signatures of tornadic debris and significant tornadic debris (EF2+) were present in Kentucky.


About the author

Dr. Jonathan Fairman is the senior scientist of meteorology at Athenium Analytics. He’s an expert in atmospheric phenomena across all scales, from severe convective storms to global climate change. He leads development across all of the Athenium Analytics atmospheric products, with recent work on AtlasForecast and DexterTornado. Jonathan was born in Cleveland and holds BS and MS degrees in atmospheric science from The Ohio State University and a Ph.D. from The University of Alabama in Huntsville. He’s also a classically trained trumpet player and performs with ensembles throughout New England when he’s not thinking about the weather.