The Science of Hailstorms: How Giant Ice Balls Form in Summer Heat
Discover how powerful thunderstorm updrafts keep ice pellets suspended, allowing them to grow into destructive giants.
Hail in the Midst of Summer
Hailstorms can seem contradictory: ice falling when ground temperatures are 90°F. However, hail is born in the freezing heights of severe convective clouds.
1. Updrafts and the Embryo Layer
Inside a supercell thunderstorm, warm rising air (updrafts) can reach speeds over 100 mph. Water droplets are carried high above the freezing level, where they freeze into small ice pellets (hail embryos).
2. The Layering Process
As updrafts toss the ice pellets up and down through layers of supercooled water and freezing air, the ice collects fresh coats of water that freeze instantly. This creates a concentric ring pattern, like an onion.
3. Gravity and Destructive Impacts
When the hailstone becomes too heavy for the updraft to support, or the updraft weakens, gravity pulls it to Earth. Large hailstones can fall at speeds exceeding 75 mph, causing severe damage.
