The destructive energy of Hurricane Irma is about twice that of all bombs dropped in the Second World War, reported The Independent.
Louis Uccellini, director of the National Weather Service, said all hazards associated with the storm will be dangerous and added that he was concerned about Florida, starting with the Florida Keys.
Another hurricane expert, Kerry Emanuel of MIT, calculated and said Irma hold 7 trillion watts of energy which is twice that of all bombs used in World War II.
The hurricane has cut a swathe of deadly destruction as it roared through the Caribbean on Wednesday, claiming at least nine lives and turning the tropical islands of Barbuda and St Martin into mountains of rubble.
One of the most powerful Atlantic storms on record, the rare Category Five hurricane churned westward off the northern coast of Puerto Rico early Thursday on a potential collision course with south Florida where at-risk areas were evacuated.
Guadeloupe prefect Eric Maire called the situation in St Martin “dramatic,” saying the island — which is divided between the Netherlands and France — was without drinking water or electricity, and warning the death toll was almost certain to rise.
To the southeast, Barbuda, part of the twin island nation of Antigua and Barbuda, suffered “absolute devastation” with 95pc of properties damaged, and up to 30pc demolished, according to Prime Minister Gaston Browne.
Threat to Florida
Category Five is the highest on the scale for hurricanes in the Atlantic and hurricanes of this intensity are rare.
They can cause severe flooding, tear off roofing, shatter windows and uproot palm trees, turning them into deadly projectiles.
Irma follows hot on the heels of Hurricane Harvey which devastated swaths of Texas and Louisiana in late August. Irma was hitting the Caribbean even as two other tropical storms, Jose in the Atlantic Ocean and Katia in the Gulf of Mexico, were upgraded to hurricane status.
Florida Governor Rick Scott said Irma posed a severe threat to the entire state.
The governor has activated 1,000 members of the National Guard and another 6,000 reserve troops will be reporting for duty no later than Friday morning.
A US aircraft carrier with a field hospital and dozens of aircraft able to conduct rescue or supply missions have been put on standby.