Il Nuovo Postiglione - Hurricane Isaias set to strike Gulf Coast late Friday

Isaias is the first hurricane of an Atlantic season held in check by a historic El Nino, and is set to become the first hurricane to strike the US mainland since Milton in 2024.

Fueled by record-warm Gulf waters heated by climate change, it strengthened rapidly over the past day.

"Isaias is coming in right over us," Jane Drescoll, a 63-year-old resident of Pensacola, told AFP, clutching her hat as she spoke to AFP on the beach. She had stocked up on propane and water and said she had been through eight hurricanes since moving to the area a decade ago.

The storm's intensity could fluctuate through the afternoon, but forecasters expect it to slam into the western Florida panhandle at or near major hurricane strength -- meaning Category 3 -- before weakening over land.

The National Hurricane Center said Isaias was packing maximum sustained winds of 120 miles (195 kilometers) per hour, and was located about 195 miles south of Pensacola.

Mandatory evacuation orders are in effect in several Florida counties, and states of emergency have been declared in parts of Alabama, Florida and Georgia.

"The resources have been flowing, the preparations have been extensive and we are taking this storm very, very seriously," Florida Governor Ron DeSantis told a press briefing. "We know that this is going to be a major event in one way or another."

Storm surge combined with the tide is expected to flood normally dry areas, with the NHC warning that water could reach as high as nine feet (2.7 meters) around the Alabama-Florida border.

At least two airports in northwestern Florida were set to suspend operations.

Homeland Security Secretary Markwayne Mullin said federal authorities were coordinating with state and local governments. "To everyone in the storm's path: ask that you also do your part to stand ready. Now is the time to prepare," he posted on X.

President Donald Trump is scheduled to attend Saturday's college football game between the University of Georgia and the University of Alabama in Tuscaloosa, Alabama, but said this week he will "let the hurricane determine" his travel plans.

- Late arrival -

Isaias's late arrival is largely due to an El Nino of historic strength.

El Nino, the warm phase of the El Nino-Southern Oscillation (ENSO), creates strong vertical wind shear over the Atlantic that tends to tear storms apart.

In the Pacific, it has the opposite effect, weakening shear and giving storms room to grow. The Pacific has already produced several hurricanes this year, some of which peaked as Category 5.

Still, "there are some pockets where hurricanes are able to develop, and that's exactly what happened with Isaias," Marc Alessi, a climate scientist with the Union of Concerned Scientists, told AFP.

"Sea surface temperatures in the Gulf of Mexico are in record territory because of fossil fuel-driven climate change," he added. "Isaias was able to tap into all of that energy in the ocean to develop into a major hurricane."

Isaias has disrupted oil and gas production in the Gulf of Mexico, with platforms and rigs evacuated.

As of Thursday, about 63 percent of the region's oil production had been temporarily halted, taking nearly 1.3 million barrels a day off the market, according to the Marine Minerals Administration (MMA). About 57 percent of gas production was also suspended.

Chevron and Shell have shut down production at several Gulf sites.

E.Scozzafava--INP