Actually it is kinda hard to explain. The science community to really figure it out and explain it. The old Saltys will say they can predict it and some are not off by far. A Jubilee is a natural phenomenon that accrues along our Mobile bay mainly on the east coast centered usually around the Fairhope area and slightly above and below It is where a east wind blows on an incoming tide sometimes effecting the water where the salt meets the fresh water. Somehow it will effect the sediment they say laying on the bottom causing this to rob the oxygen from the water. Which in turns drives the crabs from the water and causes the Flounder, Ells Shrimp beach themself. If I recall right there are only two other places in the world which this happens
Here is a site you might want to take a peek at
Fairhope Jubilee Picture Photo