FLORIDA, United States (AFP) — Hurricane Milton exploded in strength Monday to become a potentially catastrophic Category 5 storm bound for Florida, threatening the US state with a second ferocious storm in as many weeks.

Milton, which is also forecast to graze Mexico’s Yucatan peninsula as it churns eastward, rapidly intensified to the highest category on a scale of five, triggering evacuation orders and alarms about life-threatening storm surges in major population centres, including Tampa Bay.

Maximum sustained winds were estimated to be 160 mph (257 kilometres) per hour, the National Hurricane Center (NHC) said in its latest advisory.

“Milton’s remarkable rapid intensification is continuing” as it crossed the Gulf of Mexico, the NHC added.

While some weakening was forecast as it approaches the US coast, “the system is still likely to be a large and powerful hurricane at landfall in Florida, with life-threatening hazards at the coastline and well inland”.

The latest hurricane comes close behind deadly Hurricane Helene, and some Florida residents are fleeing for the second time in weeks.

Florida’s emergency management division has ordered mandatory evacuations for several low-lying areas.

The NHC warned of a major storm surge for Florida’s west coast beginning Tuesday night or early Wednesday, and said Tampa – a metropolitan area of more than three million people – could suffer an influx of water between eight and 12 feet (2.4 to 3.6 metres) above ground level.

Governor Ron DeSantis, who has declared 51 of Florida’s 67 counties under a state of emergency, said the race was on to clear damage from Helene ahead of Milton’s arrival.

“We need as much of this debris picked up as possible,” DeSantis told a press conference. “This creates a safety hazard, and it also will increase the damage that Milton could do with flying debris.”

The NHC also warned of storm surges raising water levels by five feet (1.5 meters) along Mexico’s Yucatan peninsula and large, destructive waves on the coast.

Rainfall of 10 inches (25 centimetres), with localised spots of up to 15 inches, are expected to cause havoc in Florida, bringing flash flooding.

Emergency workers were still struggling to provide relief in the aftermath of Helene, which killed at least 230 people in several states across the US south-east.

Rescue and recovery efforts after Helene have been hit by a wave of politically motivated false claims ahead of the November 5 presidential election.

Among the litany of disinformation is the falsehood pushed by Republican candidate Donald Trump that funds have been misappropriated by his rival for the White House, Democrat Kamala Harris, and redirected toward migrants.

Deanne Criswell, head of the Federal Emergency Management Agency (FEMA), dismissed the claims as false.

She also warned Monday that “these storms are bringing more water than they ever have and so while we have the wind risk, the water is what’s killing people”.

Researchers say climate change likely plays a role in the rapid intensification of hurricanes because there is more energy in warmer oceans for them to feed on.

President Joe Biden was briefed on Milton and said in a statement his Administration was readying “life-saving resources”.

Hurricane Helene hit the Florida coastline on September 26 as a Category 4 storm, dumping torrential rainfall and later causing massive flooding in remote inland towns in states further north, including North Carolina and Tennessee.

The storm was the deadliest natural disaster to hit the US mainland since 2005’s Hurricane Katrina, with the death toll still rising.

DeSantis said Florida has had power largely restored since last week, but that many electrical teams were deployed in other states badly hit by Helene.

He warned Milton will “remain a hurricane at some level all the way through, exiting the east coast of Florida”.