Visible by satellite, the loop current is the rush of hot Caribbean water that pushes into the Gulf between Cuba and Mexico. It bends toward the southwest coast and then whirls around east, forming a hairpin turn before swooping back out into the Atlantic via the Florida straits.

The forecast refers to the potential for rapid intensification over the Gulf of Mexico, which is when a storm gains 35 mph or more in a 24-hour period.

Tropical Storm Helene formed on Tuesday and is forecast intensify into a major hurricane before making landfall on Florida’s Gulf coast by Thursday afternoon. Here’s the latest