Then less than a month later a weak tropical storm named Rita followed Katrina into the Loop Current. Thirty hours later it was a Category 5 monster.
Both Katrina and Rita later weakened — which often happens — to Category 3 storms by landfall.
In the last several years, meteorologists have focused more attention on the Loop Current, which is only a couple of hundred miles long and not even 100 miles wide. The evidence linking it to the worst storms is beyond circumstantial, Shay said.
The meandering Loop Current, located in the southeastern gulf, provides loads of hurricane fuel. It was a key stopover for nearly all the Gulf Coast killers of the past, including Katrina and Camille, said Florida International University professor Hugh Willoughby, former director of the government's hurricane research division.