Paul, there were a lot of hailers on April 7, but I'm not sure if that is the day you mean. The storms that day were high-based, but I don't recall them as being particularly low-topped and don't have any photos that would definitively let you tell. If not that day, then I don't know.
EDIT - Yikes, I just noted that this was a really old, revived thread. Most of the links don't work on the new version of ST, but still an interesting discussion. Just did not realize I was replying to something so old!