Hurricane Helene forecast to be most powerful storm to hit US in a year

Storm forecasted to hit Florida's Gulf coast on Thursday as 40 million people under severe weather warnings

Tropical Storm Helene strengthened into a hurricane on Wednesday morning.

The tempest was labeled a category 1 hurricane and the US National Hurricane Center (NHC) said it was packing maximum sustained winds of 80mph (128km/h) as it churned in the eastern Gulf of Mexico just off the coast of the Yucatan peninsula.