Hurricane Ivan was the ninth named storm, the sixth hurricane, and the fourth major hurricane of the 2004 Atlantic hurricane season. It was a classic Cape Verde hurricane that reached Category 5 strength at its peak, and early in its path reached unprecedented intensity at low latitudes - Category 4 at only 10.6N.

After briefly being downgraded to Category 3 intensity, Hurricane Ivan struck Grenada directly on mid-day September 7 with Category 3 winds. It traveled across the Caribbean Sea, reaching Category 5 intensity before passing close to the Jamaican coast and Grand Cayman and crossing the western tip of Cuba. After moving into the eastern Gulf of Mexico its strength lessened to a Category 4, and it continued on a track towards the north-northwest, making landfall in the U.S. near Gulf Shores, Alabama.

After landfall, Ivan moved north and then turned east, bringing heavy rainfall to large areas of the southeastern United States. It then later looped south and west through Florida, and regenerated into a tropical storm for a short time in the Gulf of Mexico before moving into into Louisiana and Texas.

Formation and Track

On September 2, 2004, Tropical Depression Nine formed about 555 miles (890 km) southwest of the Cape Verde Islands. The depression strengthened gradually to tropical storm status about 610 miles (980 km) southwest of the Cape Verde Islands, moving west-northwesterly at around 16 mph (25 km/h), and was given the name Ivan on September 3.

Early September 5, Tropical Storm Ivan's winds strengthened to hurricane status 1210 miles (1950 km) east-southeast of the Lesser Antilles. By 5pm EDT, Ivan had rapidly strengthened to a strong Category Three hurricane on the Saffir-Simpson Scale with winds of 125 mph (200 km/h). Such rapid strengthening was unprecedented at such low latitudes in the Atlantic basin.

Hurricane Ivan passed just west of Grenada in the Caribbean Sea on September 7, 2004 at 3:45pm EDT. At the time, Ivan was a Category 3 storm. As Ivan traveled west, it weakened to Category 2. But on September 7, shortly after passing over Grenada on its way into the Caribbean Sea, it re-attained Category 4 intensity with winds of 135 mph (215 km/h). St. Vincent, Grenada and Barbados were thereafter battered by the hurricane for several hours.

As Hurricane Ivan was passing just north of the Windward Netherlands Antilles and Aruba on September 9, sustained wind speed increased to 160 mph (260 km/h) thus classifying Hurricane Ivan as a Category 5 hurricane. Following this milestone, Hurricane Ivan fluctuated between category 4 and 5 status, which is typical of intense hurricanes.

The storm continued west-northwest, heading straight for Jamaica. As Hurricane Ivan approached the island late on September 10, it began a westward jog which kept the eye and the strongest winds to the south and west. After clearing Jamaica, it resumed its more northerly track, regaining Category 5 intensity with sustained wind speeds of 165 mph (270 km/h).

Ivan spent most of September 11 traveling west at Category 4 strength, staying just off the southern coast of Jamaica. Ivan's intensity continued fluctuating, with the storm temporarily re-attaining Category 5 strength before passing within 30 miles (45 km) of Grand Cayman at Category 4, bringing hurricane force winds onto the island.

After passing the Cayman Islands, Hurricane Ivan regained Category 5 strength again and brushed the western tip of Cuba late on September 13, with its eyewall coming on shore. With most of its central circulation staying offshore, Ivan was able to pass through the Yucatan Channel with no loss of strength. Once over the Gulf of Mexico, Hurricane Ivan lost some strength, dropping back to a 140 mph (225 km/h) Category 4 hurricane, but maintained that intensity as it traveled north to the coast of the United States.

Around 3am EDT September 16, Ivan struck the U.S. mainland near Gulf Shores, Alabama. At the time, Ivan's maximum sustained winds had dropped to 120 mph (210 km/h). This drop in strength was accompanied by a disruption of Ivan's eyewall. In fact, the southwestern portion of the eyewall had all but disappeared in the hours before landfall.

Hurricane Ivan continued inland, maintaining hurricane strength until it was over central Alabama. Late on the 16th, Ivan weakened to a tropical depression over northeastern Alabama. On September 18, remnants of Ivan drifted off the mid-Atlantic coast of the United States into the Atlantic ocean as the associated low pressure disturbance continued to dump rain on the east coast of the United States.

Ivan lost tropical characteristics on September 18 while crossing Virginia. The remnant low crossed the coast of New Jersey later that day and advisories were discontinued. Nevertheless, on the morning of September 21, some of its remnants combined with a low-pressure system to pelt Cape Breton Island of Nova Scotia, Canada with hurricane-force winds, flooding some roads, felling trees, and leaving thousands without power.

Ivan reformed into a tropical depression on September 22, 2004 in the Gulf of Mexico after having traveled in a circular motion through the southeastern United States. On the evening of September 23, the revived Ivan made landfall near Cameron, Louisiana as a weak tropical storm. Ivan weakened quickly as it traveled overland into southeast Texas.

Aftermath

Hurricane Ivan killed 65 people in the Caribbean, three in Venezuela, and 26 in the United States, including fifteen in Florida. 31 more deaths in the U.S. were indirectly attributed to Ivan. Tornadoes spawned by Ivan struck communities along concentric arcs on the leading edge of the storm. Blountstown and Panama City Beach, Florida suffered two of the most devastating tornadoes.

The heaviest damage along the U.S. coastline was observed in Baldwin County, Alabama on the western side of the storm, and Pensacola and Fort Walton Beach, Florida on the eastern and windy leading edge of the storm. Shattered windows from gusts and flying projectiles experienced throughout the night of the storm were common. Early estimates had put damage in the U.S. at $5 to 15 billion.

In Pensacola, the Interstate 10 bridge across Escambia Bay was heavily damaged, with as much as a quarter-mile (400 m) of the bridge collapsing into the bay. The causeway that carries U.S. Highway 90 across the northern part of the same bay was also heavily damaged. Virtually all of Perdido Key, an area on the outskirts of Pensacola, was essentially leveled. High surf and wind brought extensive damage to Orange Beach just over the border in Alabama.

Further inland, Ivan caused major flooding, bringing the Chattahoochee River near Atlanta and many other rivers and streams to levels at or near 100-year records. The Delaware River and its tributaries crested just below their all-time records set by Hurricane Diane in 1955. In Western North Carolina, many streams and rivers reached well above flood stage causing many roads to be closed. The Blue Ridge Parkway as well as Interstate 40 through the Pigeon River gorge in Haywood County, North Carolina sustained major damage.

The Caribbean Development Bank estimates Hurricane Ivan caused over $3 billion of damage on island nations, mostly in the Cayman Islands, Grenada and Jamaica. Hurricane Ivan caused an estimated $19 billion in damage in the U.S. alone, making it the second costliest hurricane on record, ranking just above Hurricane Charley's $16 billion but well below Hurricane Andrew's $26 billion. Hurricane Hugo, which had been the second costliest hurricane since 1992, dropped to sixth after Hurricane Andrew, Hurricane Ivan, Hurricane Charley, Hurricane Frances, and Hurricane Jeanne.