Tropical Storm Arthur, first named storm of hurricane season, forms off Florida

It is the sixth year in a row that a named storm has formed before the official start of hurricane season on 1 June

Police on Hollywood Beach Broadwalk in Florida on patrol during the coronavirus pandemic (AP)

Tropical Storm Arthur, the first named storm of the hurricane season, has formed off the coast of Florida.

It is the sixth year in a row that a storm significant enough to be named has developed before the official start of hurricane season on 1 June.

The US National Hurricane Centre in Miami issued a tropical storm warning for North Carolina, where it is expected to drop one to three inches of rain on Sunday night and Monday morning. The warning applies to coastal areas from Surf City to Duck, including Pamlico and Albemarle Sounds.

Beachgoers are being warned to stay out of the water as the storm will cause life-threatening surf and rip currents. Some trees could be brought down and there could be power cuts.

Tropical Storm Arthur is expected to stay offshore from Florida, Georgia and South Carolina. It is expected to strengthen as it moves northeastwards but should change into a non-tropical low pressure system by Tuesday.

The centre of the storm on Sunday morning was 380 miles south-southwest of Cape Hatteras, North Carolina. It had sustained winds of 40mph and was moving north-northeast at 9mph.

Colorado State University hurricane researcher Phil Klotzbach told the Associated Press that while there may be a component of warming waters and climate change in other pre-June storms, Arthur is more of a subtropical storm system than a traditional named storm and its water is cooler than what's usually needed for storm formation.

Jonathan Kegges, a meteorologist at News 6 Team in Orlando, Florida, said an early storm did not necessarily signify a busy hurricane season ahead.

He said: "There have been 15 seasons prior to this one where a storm has formed before June 1. Nine of those seasons did produce an above average season, but four of them were below. The other two were average.

"The busiest hurricane season on record, 2005, saw the first storm develop June 8. 2004 was another awful hurricane season especially remembered by Floridians. The first named storm that season didn't happen until July 31."

The Associated Press contributed to this report