The range of tropical storm warnings in the Caribbean has been extended to include Florida.

The US National Hurricane Centre warned that tropical storm Dorian could reach hurricane strength for a time before weakening.

“Heavy rainfall from intense thunderstorms are anticipated,” the Foreign and Commonwealth Office cautioned in an updated travel advisory

The tropical storm is tracking across the Atlantic and the eastern Caribbean and is expected to reach Puerto Rico and southern Florida.

Puerto Rico declared a state of emergency as the storm carried winds of 50mph 270 miles east of the island.

Hurricane Maria struck Puerto Rico almost two years ago, killing an estimated 2,975 people and causing a humanitarian crisis.

The latest storm is forecast to affect the Dominican Republic and Haiti today, with holidaymakers told to “exercise due caution and monitor local news and weather reports”.

British tourists in the region were advised to monitor the progress of approaching storms and follow instructions issued by local authorities, including evacuation orders.

Dorian passed near St Vincent and the Grenadines yesterday with no reports of serious damage.

But government offices, businesses and all non-essential services remain closed until today.

“The airport is open; if you’re visiting, follow the advice of the local authorities and your tour operator,” the FCO said.