# Supercell (DD-612)

> A supercell is a thunderstorm with a deep, persistent rotating updraft called a mesocyclone. The National Weather Service (NWS) office in Amarillo says supercells are the least common type of thunderstorm but are especially prone to severe weather, including damaging winds, very large hail and sometimes tornadoes. NOAA's JetStream adds that they cause nearly all significant US tornadoes and most hailstones larger than a golf ball, and that their updrafts can exceed 100 mph (160 km/h). The key ingredient is vertical wind shear, a change in wind speed and direction with height. NWS Amarillo calls moderate to strong shear between the surface and about 20,000 ft the most critical factor. Shear creates horizontal spin, and a strong updraft tilts it upright and stretches it into a rotating column. Shear also tilts the storm, keeping its updraft and downdraft apart so rain-cooled air doesn't choke it off. That's why a supercell can last for hours. Wikipedia gives a typical life of 2–4 hours, sometimes more than 7. Fewer than about 30% produce tornadoes. In a 2017 study, Johannes Dahl showed that simple tilting of the environment's horizontal spin doesn't fully explain the rotation near the ground. Supercells are often classified as classic, low-precipitation and high-precipitation. The footage shows a time-lapse of a towering storm cloud over farm fields.

- Department: Nature (also Science)
- First published: 2025-07-11
- Last updated: 2025-07-11
- Permalink: https://detailenjoyer.com/case/supercell/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-612-F01**: A supercell's rotating updraft is called a mesocyclone. _(Write-up · Exhibit A (The mesocyclone))_
- **DD-612-F02**: Supercells typically last 2–4 hours. _(Write-up · Exhibit C (Built to last))_

## Write-up

A thunderstorm that spins. Its rotating updraft, the mesocyclone, can last for hours.

1. **The mesocyclone**: A supercell is set apart by its deep, persistent rotating updraft, the mesocyclone.
2. **Shear is key**: Moderate to strong change in wind speed and direction with height is the most critical ingredient.
3. **Built to last**: Shear tilts the storm, so its downdraft doesn't choke the updraft. Supercells typically last 2–4 hours.
4. **Severe weather**: Supercells cause nearly all significant US tornadoes and most hail larger than a golf ball.
5. **Still studied**: Dahl (2017) showed tilting alone doesn't fully explain rotation near the ground.

## Related case files

- [Hail Storming (DD-633)](https://detailenjoyer.com/case/hail-storming/): Hail storms like these are often produced by supercells
- [Eye of the Storm (DD-712)](https://detailenjoyer.com/case/eye-of-the-storm/): Another rotating storm system
- [Neptune (DD-126)](https://detailenjoyer.com/case/neptune/): I paired it with Earth's most powerful storms
- [Cloud Envy (DD-154)](https://detailenjoyer.com/case/cloud-envy/): I linked more weather
- [Linking Up (DD-302)](https://detailenjoyer.com/case/linking-up/): I paired it with the storms that make the most lightning

## Reel vs. record

- **Note**: 'Difference in wind speed and with height': wind shear is a change in wind speed and direction with height. NOAA says the ideal setup is winds turning clockwise as you go up.
- **Note**: 'Can last for hours': typically 2–4 hours, and some tornadic supercells last more than 7. Shear keeps the updraft and downdraft apart, so rain-cooled air doesn't shut the storm down.
- **Note**: 'Tilts and stretches horizontal spin into the storm's updraft': that's the standard explanation for midlevel rotation. Dahl (2017) showed it doesn't fully explain rotation near the ground.
- **Note**: 'Highly organized, powerful type of thunderstorm': and the least common type. Supercells cause nearly all significant US tornadoes, but fewer than about 30% produce one.
- **Missing**: supercell updrafts can exceed 100 mph (160 km/h), and the storms produce most US hailstones larger than a golf ball.

## Video: Supercell: A Thunderstorm That Spins

- Duration: 22.8 s · Published: 2025-07-11
- File: https://detailenjoyer.com/assets/videos/DL93y9fNHRz.mp4

### Transcript

DID YOU KNOW? A supercell is a highly organized, powerful type of thunderstorm distinguished by its rotating updraft called a mesocyclone. Unlike ordinary thunderstorms, which typically have short-lived vertical updrafts, a supercell's persistent, rotating updraft can last for hours. This rotation is caused by wind shear, difference in wind speed and with height, which tilts and stretches horizontal spin into the storm's updraft. NOW YOU KNOW!

## Questions & answers

**Q: What is a supercell's rotating updraft called?**  
A: Its defining feature. _(Source: Write-up · Exhibit A (The mesocyclone) · National Weather Service Amarillo: What is a supercell?; NOAA JetStream: Types of Thunderstorms)_

**Q: What is the most critical ingredient for a supercell, according to the NWS?**  
A: Change in wind speed and direction with height. _(Source: Write-up · Exhibit A (The mesocyclone) · National Weather Service Amarillo: What is a supercell?; NOAA JetStream: Types of Thunderstorms)_

**Q: How long do supercells typically last?**  
A: Some last more than 7 hours. _(Source: Write-up · Exhibit B (Shear is key) · National Weather Service Amarillo: What is a supercell?; NOAA JetStream: Types of Thunderstorms)_

**Q: Roughly what share of supercells produce tornadoes?**  
A: Per Wikipedia. _(Source: Write-up · Exhibit A (The mesocyclone) · National Weather Service Amarillo: What is a supercell?; NOAA JetStream: Types of Thunderstorms)_

**Q: How fast can supercell updrafts get?**  
A: About 160 km/h, per NOAA. _(Source: Write-up · Exhibit A (The mesocyclone) · National Weather Service Amarillo: What is a supercell?; NOAA JetStream: Types of Thunderstorms)_

## Sources

- [National Weather Service Amarillo: What is a supercell?](https://www.weather.gov/ama/supercell)
- [NOAA JetStream: Types of Thunderstorms](https://www.noaa.gov/jetstream/tstrmtypes)
- [Wikipedia: Supercell](https://en.wikipedia.org/wiki/Supercell)
- [Dahl (2017), Tilting of Horizontal Shear Vorticity and the Development of Updraft Rotation in Supercell Thunderstorms, Journal of the Atmospheric Sciences](https://doi.org/10.1175/JAS-D-17-0091.1)

## Cite this case file

Easterling, Marcus. "Supercell." The Detail Department (DetailEnjoyer), case file DD-612, last updated Jul 11, 2025. https://detailenjoyer.com/case/supercell/