Tropical Storm Idalia strengthens as it threatens to strike Florida

Residents along Florida’s Gulf coast were warned of an “increasingly dangerous situation” on Monday as Tropical Storm Idalia continued to bulk up off the coast of Cuba and threatened to strike the state later in the week as a major hurricane.

With the storm moving north on a path almost parallel to Florida’s west coast, the location of its landfall, expected early Wednesday, was difficult to predict, forecasters at the National Hurricane Center (NHC) in Miami said in a late-morning briefing.

But there was growing confidence in the intensity of Idalia, which was strengthening in the abnormally hot water of the Gulf of Mexico.

“Steady to rapid intensification is predicted beginning Tuesday while Idalia traverses the warm waters of the eastern Gulf and the upper-level environment becomes more favorable,” NHC officials said.

Winds of 115mph are expected at landfall, making the storm a category 3 hurricane. Any hurricane higher than a category 2 is considered major.

Forecasters were also predicting storm surge of up to 11ft, which could bring significant inland flooding in vulnerable areas north of Tampa.

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Idalia would be the first hurricane to strike Florida since Nicole in November 2022, and the first major cyclone since Hurricane Ian ravaged the south-west of the state and killed almost 150 people last September.

Joe Biden approved a federal emergency declaration for the state on Monday, pledging his “full support” during a conversation with Republican governor Ron DeSantis. The president said the federal emergency management agency (Fema) had deployed personnel and resources to Florida ahead of the storm.

The heavily populated Tampa Bay area remained on the southern edge of the NHC’s “cone of uncertainty”. But DeSantis, who broke off from his presidential campaign in Iowa to return to the state and oversee preparations for Idalia’s arrival, warned of possible widespread impacts.

“There really doesn’t seem anything to prevent it from continuing to strengthen. And we’ve seen this before, with Hurricane Michael that continued to gather strength,” he said at a Monday morning press conference at the Florida emergency operations center in Tallahassee.

“This is going to be a major impact and Floridians should expect that this storm will be a major category 3-plus hurricane, so please prepare accordingly.”

DeSantis said 1,100 national guard personnel had been activated, with high-wheeled vehicles and aircraft, and other state agencies were on standby for rescue missions.

Additionally, he said, thousands of electricity workers were lined up to restore power lost in the storm, and schools in a number of counties in Idalia’s predicted pathway would be closed until at least Thursday.

Forty-six of Florida’s 67 counties were under an emergency declaration after DeSantis added 13 more on Monday, freeing up resources for recovery and relief efforts.

“If you are in the path of this storm, you should expect power outages,” DeSantis said at a briefing Sunday. “There’s a lot of trees that are going to get knocked down, the power lines are going to get knocked down, that is just going to happen, so just be prepared for that and be able to do what you need to do.”

In the NHC’s early briefing Monday, hurricane specialist Eric Blake said the environment was “conducive for significant strengthening” of Idalia.

“The risk continues to increase for life-threatening storm surge and dangerous hurricane-force winds along portions of the west coast of Florida and the Florida Panhandle, beginning as early as late Tuesday,” he wrote.

He urged residents to “prepare for possible significant impacts, and monitor future updates … for this increasingly dangerous situation”.

The rise in intensity in Atlantic hurricanes has increasingly been blamed on the climate crisis, with researchers warning earlier this year that “extremely active” seasons are twice as likely as they were in the 1980s because of global heating.

Earlier this month, forecasters at the National Oceanic and Atmospheric Administration’s climate prediction center (CPC) upgraded their outlook for the 2023 Atlantic hurricane season to “above normal”, reflecting “unprecedented” sea temperatures off Florida and elsewhere.

“The main climate factors … are the ongoing El Niño and the warm phase of the Atlantic multi-decadal oscillation, including record-warm Atlantic sea surface temperatures,” said Matthew Rosencrans, lead hurricane season forecaster at the CPC.

In its 10 August update, the center said it now expected six to 11 hurricanes before the Atlantic season ends 30 November, of which two to five are predicted to be major hurricanes.

With category 4 Hurricane Franklin currently swirling in the Atlantic but posing only a passing threat to Bermuda, Idalia would become only the third hurricane – and second major cyclone – of the season.