US coast braces for impact as tropical storm strengthens into a hurricane with urgent storm surge warning issued - here's where it'll make landfall

Tropical Storm Debby has been upgraded to a Category 1 hurricane by the National Hurricane Center, and it continues on a collision course with the Florida coastline.

The agency issued a storm advisory at 11pm warning that the hurricane has winds of 75 miles per hour, presenting a 'major flood threat' to the southeastern US this week.

A hurricane warning is now in effect for the Florida gulf coast from the Suwannee River to the Ochlockonee River. 

Hurricane Debby is likely to threaten multiple areas of Florida with flooding, but the exact timing of rainfall is still undetermined.

Current models show rain starting on Sunday and lasing until the middle of the week, estimates that could shift depending on the speed and intensity of the storm.