MIAMI • Irma picked up strength, becoming an "extremely dangerous" Category Five hurricane as it approached the Caribbean yesterday, the Miami-based National Hurricane Centre (NHC) reported.
"Preparations should be rushed to completion in the hurricane warning area," the centre said.
The monster hurricane, the most powerful on the five-level Saffir- Simpson scale, is about 440km east of the island of Antigua, packing maximum sustained winds of 280kmh.
Irma was expected to make landfall along the string of French islands that includes Guadeloupe before heading to Haiti and Florida.
The storm was moving towards the west at 22kmh, and is expected to drop between 10cm and 20cm of rain when it hits land.
"These rainfall amounts may cause life-threatening flash floods and mudslides," the NHC warned.
The storm is also expected to "cause life-threatening surf and rip current conditions".
In preparation for the storm, the government of the economically struggling Puerto Rico has declared a state of emergency and activated the National Guard.
The US territory, home to about 3.4 million people, has 456 emergency shelters prepared to house up to 62,100 people.
RSAF Chinooks have flown 14 sorties
Defence Minister Ng Eng Hen said in a Facebook post yesterday that the RSAF's four Chinook helicopters which are assisting the Texas Army National Guard in Hurricane Harvey relief operations had so far flown 14 sorties to deliver relief supplies.
"Hurricane Harvey's destructive force and floods... displaced nearly 1 million people and killed nearly 50 people," said Dr Ng.
"Having been based in Texas for 21 years, it was only natural for the RSAF to offer help to assist in this crisis, as we feel very much a part of that community."
The helicopters are based at the RSAF's Peace Prairie detachment in Texas.
Some 34 RSAF personnel, comprising pilots, aircrew and engineers, have been deployed for the mission.
Puerto Rico also froze prices on basic necessities, including food and water, medicines, power generators and batteries.
Telemundo TV station WIPR in Puerto Rico showed long lines of shoppers stocking up on bottled water, flashlights and other essentials.
The executive director of the state power authority, Mr Ricardo Ramos, said the grid is vulnerable due to lack of investment, and parts of the territory could be without power for three to four months.
"We're preparing for the worst- case scenario," he added.
In Florida, Governor Rick Scott said on Twitter late on Monday that President Donald Trump has "offered the full resources of the federal government as Floridians prepare for Hurricane Irma".
The NHC cautioned it was too early to forecast the storm's exact path or what effects it might have on the continental United States, but warned of likely effects hitting some areas by later this week.
"There is an increasing chance of seeing some impacts from Irma in the Florida peninsula and the Florida Keys later this week. In addition, rough surf and dangerous marine conditions will begin to affect the south-eastern US coast by later this week," the centre said.
Irma will be the second powerful hurricane to hit the US and its territories in as many weeks, after Hurricane Harvey in Texas and Louisiana.
AGENCE FRANCE-PRESSE, REUTERS