 After entering the southern Gulf of Mexico , Hurricane Ivan weakened to Category 4 status by 0600 UTC on September 14 . As it gradually turned to the north , southwesterly flow from a large trough over the central United States increased wind shear over the hurricane . An eyewall replacement cycle , along with dry air and restricted outflow , contributed to the weakening . By late on September 14 the weakening trend ceased as the eyewall became better defined , and Ivan was expected to restrengthen slightly over an area of warmer water temperatures . The eye diameter expanded to 60 miles ( 95 km / h ) , though concurrently westerly wind shear and dry continued to increase . As Ivan approached the Gulf Coast of the United States , Hurricane Hunters reported erosion of the southern portion of the eyewall , and cooler waters just offshore contributed to further weakening . At around <unk> UTC on September 16 , Hurricane Ivan made landfall just west of Gulf Shores , Alabama with an intensity of 120 mph ( 195 km / h ) ; the strongest winds occurred over a narrow area near the southern Alabama and western Florida border . Its landfall was accompanied by a 10 – 15 feet ( 3 – 4 @.@ 5 m ) storm surge from Destin , Florida westward to Mobile Bay . 
