Surge could rise to as much as 20ft in some spots after huge storm strengthened as it careened across Gulf of Mexico

Hurricane Helene made landfall along the Florida coast on Thursday night as a powerful and potentially disastrous category 4 storm, bringing chaos to a wide swathe of the Gulf coast and threatening high winds, storm surges and drenching rainfall.

Helene was located about 70km east-southeast of Tallahassee, Florida, with maximum sustained winds of 225 kph, the Miami-based UA National Hurricane Center said late on Thursday.