Hurricane Ian made landfall in Florida as a Category 4 storm. Heavy rain, high winds and flooding are impacting the state.
Climate change added at least 10% more rain to Hurricane Ian, a study prepared immediately after the storm shows.
Thursday's research, which is not peer-reviewed, compared peak rainfall rates during the real storm to about 20 different computer scenarios of a model with Hurricane Ian's characteristics slamming into Florida in a world with no human-caused climate change.
"The real storm was 10% wetter than the storm that might have been,'' said Lawrence Berkeley National Lab climate scientist Michael Wehner, study co-author.
Forecasters predicted Ian will have dropped up to two feet of rain in parts of Florida by the time it stopped.
First responders with Orange County Fire Rescue use an inflatable boat to rescue a resident from a home in the aftermath of Hurricane Ian on Thursday in Orlando, Fla.
AP Photo/Phelan M. Ebenhack
Wehner and Kevin Reed, an atmospheric scientist at Stony Brook University, published a study in Nature Communications earlier this year looking at the hurricanes of 2020 and found during their rainiest three-hour periods they were more than 10% wetter than in a world without greenhouse gases trapping heat. Wehner and Reed applied the same scientifically accepted attribution technique to Hurricane Ian.
A long-time rule of physics is that for every extra degree of warmth Celsius (1.8 degrees Fahrenheit), the air in the atmosphere can hold 7% more water. This week the Gulf of Mexico was 0.8 degrees warmer than normal, which should have meant about 5% more rain. Reality turned out to be even worse. The flash study found the hurricane dropped double that β 10% more rain.
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Ten percent may not sound like a lot, but 10% of 20 inches is two inches, which is a lot of rain, especially on top of the 20 inches that already fell, Reed said.
Other studies have seen the same feedback mechanisms of stronger storms in warmer weather, said Princeton University atmospheric scientist Gabriel Vecchi, who wasn't part of the study.
MIT hurricane researcher Kerry Emanuel said in general, a warmer world does make storms rainier. But he said he is uncomfortable drawing conclusions about individual storms.
"This business above very, very heavy rain is something we've expected to see because of climate change," he said. "We'll see more storms like Ian."
Princeton's Vecchi said in an email that if the world is going to bounce back from disasters "we need to plan for wetter storms going forward, since global warming isn't going to go away."
Photos: Aerial images show devastation left by Hurricane Ian across Florida
Damaged homes and debris are shown in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
This aerial photo shows damaged homes and debris in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
This aerial photo shows damaged homes and debris in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A damaged home and debris is seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A damaged causeway to Sanibel Island is seen in the aftermath of Hurricane Ian , Thursday, Sept. 29, 2022, near Sanibel Island, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged homes are seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged homes are seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged ships and debris is seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Smoldering homes are seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach. Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Area where homes once stood is seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged boats lie on the land and water in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged boats lie on the land and water in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A man walks through a street among damaged homes and businesses and debris in Fort Myers Beach, Fla., on Thursday, Sep 29, 2022, following Hurricane Ian. (Douglas R. Clifford/Tampa Bay Times via AP)
Douglas R. Clifford
Damaged homes and businesses are seen in Fort Myers Beach, Fla., on Thursday, Sep 29, 2022, following Hurricane Ian. (Douglas R. Clifford/Tampa Bay Times via AP)
Douglas R. Clifford
Boats lay wrecked and piled up at Diversified Yacht Services in Fort Myers Beach, Fla., on Thursday, Sep 29, 2022, following Hurricane Ian. (Douglas R. Clifford/Tampa Bay Times via AP)
Douglas R. Clifford
Damaged boats and structures are seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
The remnant of a pier is seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Commercial business are seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A home burns on Sanibel Island in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A home burns on Sanibel Island in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A home burns on Sanibel Island in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Homes under construction are seen missing their roofs in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, on Sanibel Island, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damagd homes are seen in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A section of the Sanibel Causeway was lost due to the effects of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Steve Helber)
Steve Helber
Boats are stacked up against the Port Sanibel Marina Motel after Hurricane Ian ran through the area, Thursday, Sept. 29, 2022, in Fort Meers, Fla. (AP Photo/Steve Helber)
Steve Helber
Damaged structures are seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged boats are seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Livestock move in a flooded field in the aftermath of Hurricane Ian, Thursday, Sept. 29, 2022, on Sanibel Island, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged homes are seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, on Sanibel Island, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
Damaged and missing homes are seen in the wake of Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers Beach, Fla. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A mobile home community that sustained wind damage caused by Hurricane Ian is seen in this aerial view, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
Power company crew trucks drive on a flooded street on their way to help communities impacted by Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
Homes that sustained wind damage caused by Hurricane Ian are seen in this aerial view, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
A mobile home community sustained damage caused by Hurricane Ian as seen in this aerial view, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
Homes are surrounded by flood waters caused by Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
A mobile home community sustained wind damage caused by Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
A marina sustained damage caused by Hurricane Ian, Thursday, Sept. 29, 2022, in Barefoot Beach, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
Damage caused by Hurricane Ian is seen in this aerial view, Thursday, Sept. 29, 2022, in Barefoot Beach, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
Debris is piled up at the end of a cove following heavy winds and storm surge caused by Hurricane Ian Thursday, Sept. 29, 2022, in Barefoot Beach, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
A damaged causeway to Florida's Sanibel Island is seen in the aftermath of Hurricane Ian on Thursday, Sept. 29, 2022. (AP Photo/Wilfredo Lee)
Wilfredo Lee
A mobile home community sustained wind damage caused by Hurricane Ian, Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Marta Lavandier)
Marta Lavandier
In this photo taken by a drone, shrimping boats and powerboats lie strewn atop homes after the passage of Hurricane Ian, on San Carlos Island, in Fort Myers Beach, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
In this photo taken by a drone, boats lie scattered amidst mobile homes after the passage of Hurricane Ian, on San Carlos Island, in Fort Myers Beach, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
In this photo taken by a drone, damaged mobile homes lie scattered after the passage of Hurricane Ian, on San Carlos Island, in Fort Myers Beach, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
In this photo taken by a drone, the two-story Getaway Marina building, front, lies reduced to rubble as displaced boats rest along the roadside and a trailer park, at top, lies nearly devoid of homes, following the passage of Hurricane Ian, on San Carlos Boulevard in Fort Myers Beach, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
Cars drive on a flooded street caused by Hurricane Ian Thursday, Sept. 29, 2022, in Fort Myers, Fla. Climate change added at least 10% more rain to Hurricane Ian, a study prepared immediately after the storm shows. (AP Photo/Marta Lavandier)
Marta Lavandier
Rescue personnel search a flooded trailer park after Hurricane Ian passed by the area Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Steve Helber)
Steve Helber
Receding floodwaters surround homes near downtown, one day after the passage of Hurricane Ian, in Fort Myers, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
Displaced boats rest lie strewn along the San Carlos Boulevard, one day of the passage of Hurricane Ian, in Fort Myers Beach, Fla., Thursday, Sept. 29, 2022. (AP Photo/Rebecca Blackwell)
Rebecca Blackwell
A section of the Sanibel Causeway was lost due to the effects of Hurricane Ian Thursday, Sept. 29, 2022, in Fort Myers, Fla. (AP Photo/Steve Helber)
Steve Helber