Normally with a low-pressure system, rain tapers off as the warm front moves north. However, a diffluence above Louisville pushed the storm northeast, setting its path inland and south of Cincinnati. A diffluence occurs when high-atmosphere winds are blowing away from each other. Mr. Wilkinson said. The massive storm capped several weeks of rainfall over large regions of the river basin.
Experts say that combination is what caused the Ohio River to flood.
At its peak March 5, the Ohio River at Cincinnati was pushing 690,000 cubic feet of water per second. To give a sense of scale, the Licking River that swamped Falmouth was moving at about 100,000 cubic feet per second at its peak March 4. Mr. Wilkinson said.