What made the Mayfield tornado so powerful? In this episode, we break down the unique setup that allowed the Quad-State supercell to tear across four states and produce some of the most intense tornado damage in recent memory.

Unlock your storm chasing potential by subscribing to the Chaser Academy!

Join our free community and connect with fellow storm chasers!

00:00 Atmospheric Setup

03:33 Wind Shear and Moisture

05:02 Triggering the Supercell

07:46 Tornadogenesis

10:27 Continuous or Cyclic?

12:27 Factors for Longevity

14:38 Comparing Historic Supercells

16:21 Key Ingredients for Marathon Supercells

On December 10, 2021, a violent supercell tore across four states, producing catastrophic damage and a long-tracked tornado that devastated Mayfield, Kentucky. But what made this event so unusual? In this episode, we take a deep dive into the Quad-State Supercell to understand why it lasted so long, why the tornadoes it produced were so intense, and whether this was truly one continuous tornado or a series of destructive segments.

We begin by unpacking the large-scale atmospheric setup. A broad, zonal jet stream with a weakly tilted trough may not sound like a classic outbreak pattern—but that’s exactly what set the stage. The subtlety of the setup actually favored discrete supercells over squall lines, giving individual storms space to grow. Add in a robust low-level jet, strong directional wind shear, and abundant warm-sector moisture, and you have a stealthy but volatile environment primed for high-impact tornadoes.

As the storm initiated near Little Rock, radar quickly showed signs of organization—rotation, mesocyclones, even a BWER (bounded weak echo region). Once tornadoes touched down near Bay, AR, the storm entered a long-duration phase of intensity. With consistent inflow, a surface low tracking northeast, and environmental parameters that remained remarkably stable, the supercell maintained strength deep into the night.

Was it one tornado the entire way? We explore the evidence. A likely brief lift in Tennessee, supported by radar and lack of surface damage, suggests two long-track tornadoes instead of one. We also examine the role of rear flank downdraft (RFD) surges and how they may have temporarily disrupted tornadogenesis.

Finally, we compare the event to historic long-track tornadoes, including the 1925 Tri-State Tornado and the 2006 Six-State Supercell, identifying key similarities—and important differences—that make the Quad-State Supercell a case study in how subtle atmospheric ingredients can lead to historic outcomes.