Tropical Storm Helene strengthens amid hurricane warnings for Florida and Mexico

Sandbags are filled at a public site while residents prepare their homes for potential flooding in Tarpon Springs, Florida, as Tropical Storm Helene approaches (Douglas R Clifford/Tampa Bay Times via AP)

Tropical Storm Helene was rapidly strengthening in the Caribbean Sea and expected to become a hurricane on Wednesday while moving north along Mexico’s coast toward the US.

It prompted residents to evacuate, schools to close and officials to declare emergencies in Florida and Georgia.