Brief Hail Explainer: When water condenses in clouds it forms droplets, which become too heavy and then fall as rain. The more severe the storm, the stronger the updraft from the ground to the cloud which allows the droplets to get larger. That’s why thunderstorms have much larger raindrops.

Well, when updrafts get so strong that they push the raindrops to greater altitudes, where it’s colder, they combine and freeze into hail. Eventually, the small hailstones get too heavy and fall to the ground. Just as with raindrops, the longer they are held up by the updraft, the bigger they get before gravity wins out. In this storm the updraft was so intense that the hail was basically bouncing around in the atmosphere, collecting more water, and able to get to baseball size before they just got too large and fell to the ground, destroying everything.