Spurred on by record sea temperatures in the Gulf of Mexico, Tropical Storm Helene this morning mushroomed into a hurricane and is expected to continue to grow into a massive storm before slamming into the Gulf Coast of Florida.

While some have forecast a Category 3 hurricane, Accuweather chief meteorologist Jon Porter says Helene could strengthen to a Category 4 before making landfall along the Florida Gulf Coast with maximum sustained winds of 130-156 miles per hour.

Earlier today, AccuWeather warned families, businesses, emergency officials and government leaders to prepare for widespread and potentially catastrophic impacts from a strengthening major hurricane by early Thursday.

Informed observers say insured property at risk could swell to $15 billion.

US president Joe Biden declared an emergency in the state and ordered federal assistance to supplement state and local response efforts owing to the developing emergency conditions.

Models indicate that the hurricane’s growth will be because of supportive conditions and unusually warm sea surface temperatures, experts say.

Anna Neely, managing director, head of Catastrophe R&D, at Howden Re, said: “It is expected to intensify into a major hurricane, with potential landfall along Florida’s Gulf Coast by Friday, leaving property owners limited time to prepare.

“The storm's trajectory and intensification pattern resemble previous hurricanes, raising the question: how severe could the damage be?

“Recent history offers some guidance.

“In the best case, a big bend landfall could result in losses mirroring Hurricane Idalia’s $3-5 billion; but a significant swing in either direction – either towards the peninsula or panhandle may produce losses that exceed $10-15 billion, similar to hurricanes Michael or Irma.

“While exact impacts are still uncertain, the key factor is whether Helene will strike a low or high-population area, with billions potentially at risk.”

The governor of Florida, Ron DeSantis, declared a state of emergency in more than 60 counties. Voluntary or mandatory evacuation orders were issued for 13 state counties.

The National Hurricane Centre said hurricane and storm conditions were expected over northeastern portions of the Yucatan Peninsula of Mexico today, with tropical storm conditions hitting portions of western Cuba.

But because of the large size of Helene, there is a danger of a life-threatening storm surge along the entire west coast of the Florida peninsula and Florida Big Bend.

The NHC advisory said: “Devastating hurricane-force winds are expected across portions of Northern Florida and southern Georgia, where the core of Helene moves inland.

“Preparations to protect life and property should be completed by early Thursday, since tropical storm conditions are expected to begin within these areas on Thursday.

“Because of Helene’s expected fast-forward speed, damaging and life-threatening wind gusts are expected to penetrate well inland over portions of the southeastern United States, including in the higher terrain of the southern Appalachians.”

Federal authorities are on the ground as electric generators, emergency food and water supplies and search-and-rescue and power restoration teams were being deployed in Florida.

The National Oceanic and Atmospheric Administration had already predicted possibly 17 to 25 named storms this year, eight to 13 of which could become hurricanes.

Much like hurricanes Katrina and Irma, Helene is not just expected to be powerful, but large and fast. That means deeper inland targets will be affected, before the winds fall, including possible tropical-storm-force winds in the Atlanta metro area on Thursday night into Friday morning.