Hurricane Ian briefly reached maximum Category 5 status before weakening to a Category 4 storm as it blasted ashore last September in southwest Florida, eventually causing over $112 billion in damage in the U.S. and more than 150 deaths directly or indirectly, the National Oceanic and Atmospheric Administration reported Monday.
The report, which NOAA releases for all major tropical storms, also says Ian was the costliest hurricane in Florida history and the third-costliest ever in the U.S. as a whole. In addition to Florida, Ian impacted Georgia, Virginia, the Carolinas and Cuba before it fell apart Oct. 1.
The NOAA report elevates Ian to one of the most powerful tropical cyclones on record as a Category 5 with winds estimated at 161 mph (259 kph) on Sept. 28 after passing by the Dry Tortugas islands. Although it weakened to a Category 4 storm when it struck Florida later that day with winds of 150 mph (241 kph), the storm is now on the list of deadly monsters such as Camille, Hugo, Andrew, Katrina, Wilma and Michael.
In addition to the winds, Ian produced major storm surge across the southwestern Gulf coast of Florida. For example, the peak storm surge at hard-hit Fort Myers Beach was between 10 and 15 feet (3 and 4 meters) above ground level. At nearby Sanibel, the surge was a high as 13 feet (3.9 meters).
“Ian made landfall in a region extremely vulnerable to storm surge,” the NOAA report says. “In southwestern Florida, the catastrophic storm surge and wind left a huge swath of complete destruction.”
Storm surge drowning was the leading cause of death during the storm with 41 deaths, with 12 additional fatalities due to inland flooding in central and eastern Florida. There were 66 deaths in Florida directly attributable to the storm, NOAA concluded.
The U.S. total of 156 fatalities includes indirect deaths such as heart attacks, electrocution from power lines, inability to reach medical help and vehicle accidents. Of those, 84 were in Florida.
Victims ranged in age from 6 to 101 years old, but the median age of storm-related deaths was 72, NOAA found.
“It is possible this is a reflection of demographics in the counties of southwest Florida but is consistent with other hurricane landfalls where the oldest die at the highest rates,” the report says.
More than 4.4 million customers, or about 9 million people, lost power in the U.S. during Hurricane Ian from Sept. 28 to Oct. 1, NOAA found. Florida led the way in power outages with more than 3 million customers, with thousands more in South Carolina, North Carolina and Virginia.
More than $109 billion of the estimated $112 billion in storm damages happened in Florida, with more than 52,000 structures impacted in Lee County alone and 5,369 completely destroyed. Inland flooding from swollen rivers, some at record levels, damaged or destroyed hundreds of buildings in several central Florida counties.
The highest rainfall total from Hurricane Ian was almost 27 inches (68 centimeters) at Grove City, Florida, just north of the landfall location at Cayo Costa. Rainfall between 10 and 20 inches (25 and 50 centimeters) was widespread across Florida.
As for Hurricane Ian forecasts, NOAA says the track errors were lower than those over the previous 5-year period while still acknowledging some difficulty in determining the exact location of expected landfall. There have been questions raised following the storm if the warnings were sufficient to allow people, especially the elderly, enough time to escape.
“In general, storms that parallel a coastline tend to be more challenging to predict because a small change in heading can cause large differences in the landfall location,” the NOAA report says. “Ian was an example of this particular challenge.”
The quick intensification also was difficult to predict. NOAA noted that in this area, the forecast errors were higher than those over the past five years. Storm surge watches, meanwhile, were issued beginning at 48 hours before the onset of tropical storm winds at Fort Myers Beach and the prediction of peak surge rose from a maximum of 7 feet (2 meters) to 12 feet (4 meters) a day before Ian made landfall.
NOAA also noted that its forecasters conducted 282 media interviews the last week of September and that the National Hurricane Center website was accessed about 224 million times during the storm period.