This Jubilee phenomenon only happens in the Summer, primarily in August. It is a pre-dawn phenomenon. And it only occurs in the Baldwin County section of Mobile Bay from just north of Daphne to Point Clear. It never happened on the Mobile County side; and apparently it does not occur in other bays. (Biloxi Bay, Pensacola Bay, and Pascagoula Bay have never recorded a Jubilee event, for example.)
These Jubilees are hard to predict, except for occurring in the summer, primarily in August, and pre-dawn. When one does occur, there's spreading of the word through the bay coastal towns, to Foley, and to Gulf Shores. People appear with bushel baskets and coolers. Package stores are induced to open; and people bring beer down to the waterside and pass cans to strangers in an impromptu festival! Sharing beer and cold drinks is part of the ritual. It's a spontaneous party that pops up at 3 or 4 A.M, and goes on for hours.
The participants are jubilant; and after a while go home and sleep a little late in the morning. That is why some Baldwin County businesses may open late without warning.