The icy balls that rained down on Manhattan Wednesday night might have been hail or just ice pellets, said climatologist Mary Knapp.

Q: Was the frozen precipitation that fell on Wednesday night hail or something else?

A: If you were awake at about 11 p.m. Wednesday in certain parts of Manhattan, you might have heard a thunderstorm that briefly rained down little icy balls.

The balls themselves were loud enough on the roof and windows to get me out of bed and down to my front porch to check it out. They were round and up to a quarter of an inch in size.

I certainly thought it was hail. On Thursday morning, though, when news editor Greg Doering called K-State climatologist Mary Knapp, our expert for all things weather, she said she wasn’t sure, but it was more likely graupel.


Knapp said graupel is basically little frozen balls of snow. She said it also could have been ice pellets, which is apparently not just a description but a term for a distinct form of precipitation. Ice pellets are essentially a bigger form of sleet.

I really wanted to know for sure. Fortunately, the ice balls were still frozen on the ground for inspection.

I gathered some and set out to inspect them on my kitchen counter. This is journalism, folks.

Graupel is sometimes called “soft hail,” and Knapp said if it was that, it would crumble when you press it or cut it.

I cut one of the little balls in half. It was definitely one solid piece of ice, so not graupel.

The difference between hail and ice pellets is a little more difficult for a layperson to discern.

Ice pellets form when a layer of above-freezing air is sandwiched by layers of below-freezing air. Snow falling through the warm layer melts and then refreezes into ice pellets. They tend to be translucent.

Hail forms in thunderstorms with strong updrafts that carry water droplets to a level well above freezing.

As the winds carry the hail through areas of water droplets and water vapor, it gives hail layers of transparent and translucent ice. Hail also must be at least one-fifth of an inch.

I tried to cut more of the tiny balls in half to inspect them for a layered cross-section, but to be honest, they were too small and melted too quickly to say definitively.

I couldn’t see any layers, though, and the balls seemed to be translucent, so that seems to point to ice pellets, not hail. They also just barely meet the size requirement for hail.

Now the precipitation did occur during a thunderstorm, and those are known to produce hail, but it’s less common for that to happen in February.

So the answer: inconclusive. But when in doubt, I’d go with Mary Knapp.

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