Weather Explainers

Ask A Met: Are Hurricanes Too Warm To Freeze?

Each week, our meteorologists answer a question from readers.

This week's question comes from Morning Brief reader Therese, who noted that she had read a previous column about the hypothetical situation of dropping frozen peas into a cloud. "Now that I've read about peas and hail," Therese asks, "I wonder if hurricane-force winds support hail formation? Or are hurricanes too warm to freeze?"

Meteorologist Jonathan Belles: Hard hailstones aren't common in hurricanes, but ice is increasingly thought to be at least somewhat common in a different form – graupel. Graupel is a softer form of hail that is some weird cousin of sleet.

See, hurricanes are very tall weather features that take air from very tropical locations near the surface to very cold heights and on the way upward, air attempts to freeze in those updrafts. Hurricanes, especially of the rapidly intensifying variety, are known to have very quick upward motions within them.

It is those same crazy upward motions in thunderstorms that you often find in the Great Plains in May that create gorilla hailstones. But in the warmer tropics, it is often too warm to get a hard hailstone. On the micro scale, supercooled water droplets rise quickly, bumping into other supercooled and warmer water droplets. The supercooled ones freeze on contact while the warmer ones just add a layer of water, just chilling there. That's where we get soft hail.

Several hurricane hunter flights have had to be stopped mid-flight because the planes get impacted by graupel storms as the scientists investigate hurricanes.

Do you have a question to ask the meteorologists at Weather.com? Send us an email and we’ll pick a new question each week from readers to answer.