Hurricane Irma: Florida declares state of emergency as storm is upgraded to Category 4

Dangerous storm could clip the mainland United States hard upon the heels of Hurricane Harvey, which battered Houston in the last fortnight

A hurricane watch is in place in several of the Caribbean islands as well as in Florida (Getty)

Florida has declared a state of emergency in anticipation of a possible hit by Hurricane Irma, which is about to blast through the Caribbean and could also clip the US mainland.

Irma has been upgraded to a powerful Category 4 hurricane as the Caribbean islands in its path brace themselves for its arrival.

Florida Governor Rick Scott said: “Hurricane Irma is a major and life-threatening storm and Florida must be prepared. I have continued to be briefed by the Florida Division of Emergency Management on Hurricane Irma and current forecast models have Florida in Irma’s path – potentially impacting millions of Floridians.

“In Florida, we always prepare for the worst and hope for the best and while the exact path of Irma is not absolutely known at this time, we cannot afford to not be prepared,” he added.

Hurricane advisories have been issued for territories that dot the West Indies, including parts of the Leeward Islands, the British and US Virgin Islands and Puerto Rico in preparation for the intensifying storm that could pummel the area with life-threatening wind, storm surges and torrential rain by Tuesday evening, according to the American National Hurricane Centre (NHC).

A Category 4 hurricane on the five-step Saffir-Simpson scale means sustained winds of 130-156 miles per hour (209-251 kph) with “catastrophic” outcomes, including uprooted trees and downed power lines, water and electricity outages, and significant property damage causing uninhabitable conditions, according to the Miami-based hurricane centre.

Irma, which is carrying 130 mph (215 kph) winds, also threatens the US East Coast, said the NHC, which warned it was still too early to forecast the storm's exact path or what effects it might have on the continental US.

“There is an increasing chance of seeing some impacts from Irma in the Florida Peninsula and the Florida Keys later this week and this weekend.

“In addition, rough surf and dangerous marine conditions will begin to affect the southeastern US coast by later this week,” a statement from the centre said.

Irma will be the second powerful hurricane to hit the US and its territories in as many weeks.

Residents in Texas and Louisiana are still reeling from the catastrophic effects of the deadly Hurricane Harvey, which struck Texas last month and dumped several feet of rain, destroying thousands of homes and businesses.

Irma is predicted to gather in strength over the next 48 hours and could “directly affect Hispaniola, the Turks and Caicos, the Bahamas, and Cuba as a dangerous major hurricane later this week,” the NHC said.

In preparation for the storm, the economically struggling Puerto Rico government has declared a state of emergency and activated the National Guard.

“Despite the economic challenges Puerto Rico is facing, the approved budget has $15 million for the emergency fund,” Governor Ricardo Rosselló said in a statement.

The island nation of about 3.4 million people has 456 emergency shelters prepared to house up to 62,100 people.

To help residents prepare for the storm, the Puerto Rican government activated a price freeze on basic necessities, including food and water, medicines, power generators and batteries.

Reuters