(Bloomberg) -- Florida is being swept by a line of thunderstorms set to crash down on Miami, as heavy rain that already has brought Fort Lauderdale its rainiest June day ever wrings out across southern Florida and is likely to push losses over $1 billion.

The thunderstorms dropped 3 inches (7.62 centimeters) in two hours on Fort Meyers, said Bob Oravec, a forecaster at the US Weather Prediction Center. “It’s another big day,” he said. “A very wet pattern.” 

There is a high risk of excessive rain across southern Florida, including Miami, the worst threat level, with a widespread area getting as much as 5 inches with some isolated spots getting up to 10 inches, the weather prediction center estimated.

On Wednesday, 9.54 inches fell in Fort Lauderdale, the most ever for a June day. The downpour closed ramps to the airport and flooded city streets. The wider deluge led parts of Interstate-95 to be closed, hundreds of flights to be canceled and Governor Ron DeSantis to declare an emergency in several counties including Miami-Dade, Broward, Collier, Lee and Sarasota.

The rain fell so hard and fast that it forced the weather service to issue its second-ever emergency flood warning for southern Florida’s east coast, said Sammy Hadi, a meteorologist with the agency in Miami. The National Hurricane Center is tracking the system responsible, but says it has not yet reached the level of a tropical storm.

“Regardless of whether it has a name or not, if it drops 9 inches in 24 hours there are going to be big problems,” Hadi said.

Damages are likely to top out at $1 billion or more, said Chuck Watson, a disaster modeler with Enki Research. That said, given the rising cost of homes and automobiles, storms are causing that scale of destruction more often. 

Parallels already are being drawn to April 2023 flooding in Fort Lauderdale that cost at least $1.1 billion in losses. It closed the city’s airport and brought more than 25 inches of rain in 24 hours, according to the US National Centers for Environmental Information.

The ocean around Florida is at a record warmth in some areas and the atmosphere is holding tremendous amounts of water vapor. In Miami on Wednesday, measurements recorded the second highest amount of moisture in the air for a June day, according to a Substack post by Michael Lowry, a hurricane specialist at WPLG-TV in Miami and former US National Hurricane Center scientist.

“With plenty of heat at hand, and so much water vapor, it didn’t take much of a disturbance to trigger heavy rains,” said Bob Henson, a meteorologist and author with Yale Climate Connections. “Getting two events in less than 15 months should be wake-up call for anyone who’s been dozing through the overlapping insurance and climate crises in South Florida.”

With more rain on the way, 444 flights flights already have been canceled in Miami, Fort Lauderdale and other Florida airports, according to FlightAware, an airline tracking service.

(Updates forecast starting in the first paragraph.)

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