TAMPA, Fla. (WFLA) — Hurricane Ian was posthumously upgraded to a Category 5 storm, according to a Tropical Cyclone report released by the National Hurricane Center on Monday.

The NHC report said Ian made landfall in southwest Florida as a powerful Category 4 hurricane, producing “catastrophic storm surge, damaging winds, and historic freshwater flooding across much of central and northern Florida.”

After making landfall, the storm moved into the Gulf of Mexico where favorable conditions helped propel it to a brief Category 5 strength storm. The report broke down data collected during the storm into several categories including winds and pressure, storm surge, rainfall and flooding, and casualty and damage statistics.

Winds and Pressure

The NHC says the eye of the 110-kt hurricane passed directly over the Dry Tortugas at 10 p.m. EST on Sept. 28, 2022. Afterward, Ian moved into the Gulf where “oceanic conditions remained very conducive for additional strengthening.” The storm later intensified to its peak of 140 kt — a category 5 hurricane — at 8 a.m., according to data from Air Force Reserve Unit and NOAA reconnaissance aircraft.

“It should be noted that the NHC best track intensities typically have an uncertainty of around ±10%, and that there is very little practical difference between a 140-kt category 5 and a 135-kt category 4 hurricane,” the report stated.

By the time Ian made landfall in mainland southwestern Florida, winds were estimated to be about 125 kt. Due to instrument failure, the NHC said no reliable surface observations exist from the coastal areas where the eyewall came on shore.

Rainfall and Flooding

Winds were not the only damaging effects of Ian. The NHC said Ian made landfall in a region “extremely vulnerable to storm surge,” adding that the exact track, strong winds, and large storm size contributed to the “widespread devastating impacts.”

Parts of Fort Myers Beach Peak experienced inundation levels of 10 to 15 ft above ground level.

In one location, a remote camera mounted by storm-chaser Max Olson captured the evolution of the storm surge. A timeline of images taken from the video footage revealed a home in the view of the camera floating off its foundation with large waves crashing over it. Another portion of the footage showed waves crashing over the camera, which was mounted roughly 12 ft above the road.

Counties north of Ian’s center track, including Sarasota, Hardee, DeSoto, Polk, and Manatee, experienced significant flooding when the Peace, Myakka, and Alafia Rivers, and Horse Creek all crested to record levels.

Casualty and Damage Statistics

According to the NHC report, Ian was responsible for at least 156 fatalities across the U.S. Of those, 66 are considered deaths directly caused by the storm.

Storm surge was the deadliest hazard, claiming 41 lives. There were 12 direct fatalities attributed to freshwater flooding in central and eastern Florida, eight were categorized as marine fatalities, four were related to wind, and one was due to rough surf.

A boat carrying 27 migrants from Cuba reportedly capsized off the coast of the Florida Keys in rough waters generated by the hurricane. Four passengers swam to shore and five were rescued from the water. Only seven bodies were recovered (accounting for seven of the eight marine deaths). A couple living on a separate boat that was set adrift from the Florida Keys remain missing.

Ian was also indirectly responsible for 90 casualties in the United States. The report stated the leading causes of death as the lack of access to timely medical care, accidents such a trip-and-fall during power outages, and cardiac events. Other causes included vehicular accidents, accidents related to storm preparations or clean up, carbon monoxide poisoning, suicide, and homicide.

According to the NOAA National Centers for Environmental Information, Ian was the third-costliest U.S. hurricane on record with an estimated $112.9 billion worth of damage. Of that total, $109.5 billion occurred in Florida, making Ian the costliest hurricane to ever affect the state.