# Hail Storming (DD-633)

> Hail forms inside thunderstorm updrafts. According to NOAA's National Severe Storms Laboratory (NSSL), raindrops are carried up into very cold air and freeze. The young hailstones then grow by colliding with supercooled water drops, liquid colder than freezing, which freeze onto them. A stone grows on a seed of ice, snow or dust. Water that freezes instantly traps air bubbles and makes cloudy ice, while water that freezes slowly makes clear ice. The alternating layers reflect the changing conditions a stone passes through, not just simple up-and-down trips. Hail falls when the updraft can no longer hold up its weight, and stronger updrafts can hold bigger stones. Hail 2 inches (5 cm) or larger usually comes from supercells, storms with a rotating updraft. The largest U.S. hailstone fell in Vivian, South Dakota, on July 23, 2010: 8.0 inches across and about 1.94 lb (0.88 kg). Small hail falls at roughly 9-25 mph, while stones over 4 inches can top 100 mph. 'Hail alley', where Nebraska, Colorado and Wyoming meet, averages seven to nine hail days a year. Insurers count hail as a major part of the tens of billions of dollars in U.S. severe-storm losses each year. The footage shows hail falling past a porch and windows.

- Department: Nature (also Science)
- First published: 2025-08-07
- Last updated: 2025-08-07
- Permalink: https://detailenjoyer.com/case/hail-storming/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **July 23, 2010**: A record 8.0-inch hailstone falls in Vivian, South Dakota

Full timeline: https://detailenjoyer.com/timeline/?case=hail-storming

## Quick facts

- **DD-633-F01**: Hailstones grow by catching supercooled water drops. _(Write-up · Exhibit A (How it grows))_
- **DD-633-F02**: The largest U.S. hailstone was 8.0 inches across. _(Write-up · Exhibit D (The record))_

## Write-up

Ice that grows in the clouds. Storm updrafts keep hailstones aloft until they're too heavy.

1. **How it grows**: Updrafts lift raindrops into very cold air, where they freeze and then grow by catching supercooled drops.
2. **Why it falls**: Hail falls when the updraft can't hold it up anymore. Stronger updrafts can hold bigger stones.
3. **Supercells**: Hail 2 inches or larger is usually linked to supercell thunderstorms.
4. **The record**: The largest U.S. hailstone fell in Vivian, South Dakota, on July 23, 2010: 8.0 inches across.
5. **The cost**: Insurers count hail as a major part of the tens of billions of dollars in U.S. severe-storm losses each year.

## Related case files

- [Eye of the Storm (DD-712)](https://detailenjoyer.com/case/eye-of-the-storm/): Another storm-science case
- [Drone De-icing (DD-699)](https://detailenjoyer.com/case/drone-de-icing/): More trouble from ice
- [No Perfect Crystallizations (DD-288)](https://detailenjoyer.com/case/no-perfect-crystallizations/): I paired it with the other kind of ice that falls from clouds
- [Supercell (DD-612)](https://detailenjoyer.com/case/supercell/): Hail storms like these are often produced by supercells

## Reel vs. record

- **Growth**: hailstones grow mainly by colliding with supercooled liquid drops that freeze onto them, starting from a seed of ice, snow or dust. They don't simply freeze where they are.
- **Note**: 'Layers of ice': NSSL notes the clear and cloudy layers come from changing temperature and water conditions in the storm, not just from repeated trips up and down.
- **Missing**: hail falls when the updraft can no longer hold its weight, so stronger updrafts (especially supercells) make bigger hail.
- **Note**: 'Larger than baseballs': true, and the U.S. record is 8.0 inches across (Vivian, South Dakota, July 23, 2010).
- **Note**: 'Billions': in the U.S. alone, insurers count hail as a major part of severe-storm losses that run to tens of billions of dollars a year. Spelling: 'hailstones' is one word.

## Video: Hail Storming: Ice That Grows in the Clouds

- Duration: 21.1 s · Published: 2025-08-07
- File: https://detailenjoyer.com/assets/videos/DNEhkP0ymO_.mp4

### Transcript

DID YOU KNOW? Hailstorms form when strong updrafts in thunderclouds carry water droplets high into freezing regions of the atmosphere, where they accumulate layers of ice before falling as solid balls of hail. Depending on their size, which can range from pea size to larger than baseballs, hail stones can inflict immense damage upon impact, sometimes causing billions in agricultural and property losses. NOW YOU KNOW!

## Questions & answers

**Q: What do young hailstones collide with to grow?**  
A: Liquid drops below freezing freeze onto them. _(Source: Write-up · Exhibit A (How it grows) · NOAA NSSL: Severe Weather 101, Hail Basics; NOAA NSSL: Severe Weather 101, Hail Forecasting)_

**Q: When does hail fall?**  
A: Gravity wins over the updraft. _(Source: Write-up · Exhibit B (Why it falls) · NOAA NSSL: Severe Weather 101, Hail Basics; NOAA NSSL: Severe Weather 101, Hail Forecasting)_

**Q: Hail 2 inches or larger usually comes from which storms?**  
A: Supercells have strong rotating updrafts. _(Source: Write-up · Exhibit C (Supercells) · NOAA NSSL: Severe Weather 101, Hail Forecasting)_

**Q: How wide was the record Vivian hailstone?**  
A: 8.0 inches across. _(Source: Write-up · Exhibit D (The record) · NWS Aberdeen: Record setting hail event in Vivian, South Dakota on July 23, 2010)_

**Q: Which states meet in 'hail alley'?**  
A: Seven to nine hail days a year on average. _(Source: Write-up · Exhibit B (Why it falls) · NOAA NSSL: Severe Weather 101, Hail Basics; NOAA NSSL: Severe Weather 101, Hail Forecasting)_

## Sources

- [NOAA NSSL: Severe Weather 101, Hail Basics](https://www.nssl.noaa.gov/education/svrwx101/hail/)
- [NOAA NSSL: Severe Weather 101, Hail Forecasting](https://www.nssl.noaa.gov/education/svrwx101/hail/forecasting/)
- [NWS Aberdeen: Record setting hail event in Vivian, South Dakota on July 23, 2010](https://www.weather.gov/abr/vivianhailstone)
- [Gallagher Re: Natural Catastrophe and Climate Report (2025)](https://www.ajg.com/gallagherre/-/media/files/gallagher/gallagherre/news-and-insights/2025/natural-catastrophe-and-climate-report-2025.pdf)

## Cite this case file

Easterling, Marcus. "Hail Storming." The Detail Department (DetailEnjoyer), case file DD-633, last updated Aug 7, 2025. https://detailenjoyer.com/case/hail-storming/