Hurricane Ida was so powerful it made the Mississippi River flow backward! How strong were the winds of Hurricane Ida? So strong they made the Mississippi River flow backward. According to the U.S. Geological Survey, the storm created a ‘negative flow’ at the point where the river empties into the Gulf of Mexico – sending the water backward for about two hours. A similar phenomenon happened during Hurricane Katrina in 2005 and Hurricane Isaac in 2012.