Tropical Storm Idalia appears on track to develop into a hurricane as it makes it way toward Florida's coast, forecasters said.

As of around 2 a.m. ET, the storm was moving over the southeastern Gulf of Mexico with maximum sustained winds of 70 mph, the hurricane center said.

"Rapid strengthening is predicted during the next day or so," it said, with the system forecast to become a hurricane sometime this morning.

Idalia is likely to become a "major hurricane," which is defined as Category 3 or above on the Saffir-Simpson hurricane wind scale, early tomorrow — the same day it is expected to reach the Gulf Coast of Florida, according to the hurricane center.