McMaster is expected to sign the evacuation order Friday, but he shared his plans Thursday to get people ready as soon as possible to the leave vulnerable coastal areas.
The governor also authorized up to 5,000 Georgia National Guard members to respond to the storm and expanded a state of emergency to 30 southeast Georgia counties.
Georgia Governor Nathan Deal issued a mandatory evacuation order on Thursday for the state's coast, including historic Savannah, as deadly Hurricane Irma rolled toward Florida and the southeastern United States.
The storm's exact path is uncertain, but it could affect Georgia and the Carolinas early next week.
Gov. Henry McMaster declared a state of emergency Wednesday, and while evacuations have not yet been ordered, residents along the coast have been told to prepare for that possibility. On Thursday afternoon, Deal added 24 more counties to that list.
Citing potential storm surge, Deal said a mandatory evacuation would take effect beginning on Saturday for Chatham County, which includes Savannah, and other coastal areas.
State emergency officials said they don't want people to panic but want those in hurricane-prone areas to be prepared. The Office of Residence Life and Housing is working with residential students who need assistance to relocate them to another institution in the University System of Georgia. Admission to the game is free.