Hurricane Florence is forecast to bring “life-threatening” weather conditions to the US states of North Carolina and South Carolina, with coastal Georgia and Virginia also threatened.
The Foreign and Commonwealth Office updated its travel advice to the US east coast region and warned that the storm is expected to intensify in the coming days.
Florence has the potential to make landfall on Thursday morning in coastal North Carolina as a “major hurricane” bringing 140 mph winds.
The FCO said: “Follow the advice of local authorities in North Carolina, South Carolina, Georgia and Virginia, including any evacuation orders, and monitor news and social media for more information.”
At the same time the first major hurricane alert of the traditional late summer storms season in the Caribbean was issued, including multiple islands popular with British holidaymakers.
Hurricane Isaac is forecast to strike on Thursday affecting at least two dozen islands from St Lucia and Barbados to Antigua, Barbuda, the Dominican Republic, Grenada and the British Virgin Islands.
Although September is low season in the Caribbean with major hotels stuck for the month, islanders will be anxious to avoid a repeat of catastrophic Hurricane Irma which left a trail of devastation across parts of the region a year ago.
Meanwhile, Hurricane Olivia is approaching the Hawaiian Islands as a category storm 1 with 85 mph sustained winds.
Tropical storm conditions are expected in the next 24-36 hours, with warnings in place for Hawaii and Maui and a tropical storm in place for Oahu.
“You should follow the advice of local authorities. For more information check with the Hawaii Emergency Management Agency and the Central Pacific Hurricane Center,” the FCO said.