The Storm Prediction Center is certainly a serious place. I assume this from the number of official sounding words in its parent organization: the United States Department of Commerce National Oceanic and Atmospheric Administration. Which I mention because I want you to take seriously that our government scientists have an official table for "object-to-size conversion for assessment and translation of severe hail reports." They would really prefer a measurement, thank you very much, but because there are so many estimators running around making colorful comparisons, they have a chart to compare hail size (in inches) to "object analog reported."
I mention this because that means "softball-sized hail" is a technical term. I had always wondered why the weather forecasts in Dallas said things like "quarter sized hail" instead of "hail of one inch diameter." It seemed so unscientific, even for meteorology. But now that we have experienced not just a hail storm, but break-the-bedroom-window-sized hail, I appreciate the standardization. Officially, then, hail comes in the following sizes: marble/moth ball, penny, nickel, quarter, half dollar, walnut/ping pong ball, golf ball, hen egg, tennis ball, baseball, tea cup, grapefruit, and softball.
It's a strange thing to be proud of, but I'm kind of excited that at softball-sized hail, 4.50 inches diameter, we topped the scale. The chart doesn't say what comes next. I assume that means there are physical/chemical properties that keep hail from getting any bigger, or that any bigger than softball-sized hail—-poodle-sized hail, for instance—no one would believe your folksy comparison anyway.