Repeated hurricanes near the mouth of a major river will at first be deflected , then deflected less (maybe even attracted) to the river-mouth .
The outflow of a large river like the Mississippi creates a bubble of low temperature around it's mouth . The river water is at a lower temperature than the Gulf of Mexico . A hurricane is fuelled by heat and will follow the heat contours from lower to higher energy . So a large river like the Mississipi will tend to deflect the the first hurricane . (Like Katrina).
A hurricane passing close to the Mississipi's mouth dumps a lot of warm rain and surge. A subsequent hurricane , as can be expected in a warming scenario , will thus encounter a greatly decreased deflection effect . If the heating of water in the flood-plains causes a warmer sea-temperature at the Mississipi's mouth than in the Gulf , following hurricanes would be attracted to the river mouth , instead of being deflected .
A near miss on the Mississipi's mouth will be followed by closer and closer hits until the end of the hurricane season .
High probability prediction:
Katrina will most likely be followed by at least two hurricanes this year , hitting Mississipi's mouth or close to it .