Authorities along the Georgia coast ratcheted up preparations for Hurricane Matthew, a dangerous Category 3 storm described by Channel 2 Action News meteorologist Brian Monahan as the strongest storm in the Atlantic in about 10 years.

The National Weather Service announced at 5 p.m. that the hurricane was about 400 miles southeast of West Palm Beach, Fla., north of Cuba and about 205 miles from the Bahamas. The hurricane watch had been extended northward from Fernandina Beach to the Savannah River. A tropical storm watch was issued for the Florida Gulf Coast from north of Chokoloskee to the Suwannee River.Forecasters predict the hurricane will be near Florida’s Atlantic coast by Thursday evening. By Friday night, the center of Matthew is expected to be less than 100 miles from the Georgia coast, Channel 2 meteorologist Brad Nitz said.

On Tybee Island, government buildings were boarded up and a mandatory evacuation went into effect at 3 p.m.

“We want to make sure that people are preparing for the worst,” Tybee Island Mayor Jason Buelterman said. “We hope for the best but we have to be preparing for the possibility that this will be a direct hit.”

Shortly after 5 p.m. Wednesday, Amtrak announced the suspension of all of its service in the Southeast region.Passengers with travel plans can confirm their train's status, change their plans or review refund information on Amtrak.com, via smartphone apps or by calling 800-USA-RAIL. Service alerts, passenger notices and other announcements are posted at Amtrak.com/alerts.Reports of heavy traffic heading north along I-95 in Florida began at mid-afternoon Wednesday.

The Florida Department of Transportation suspended tolls on State Road 528 because of the evacuations in Brevard County and halted construction work on interstates and evacuation route roadways as Hurricane Matthew nears.Several closures were announced ahead of Matthew's arrival in Georgia.

The Okefenokee National Wildlife Refuge announced it will be closed Thursday due to expected impact by Hurricane Matthew. "Although Okefenokee National Wildlife Refuge is not immediately on the coastline, we are expecting tropical storm force winds and approximately 5 inches of rain during the day on Friday based on the most recent weather predictions," the organization said in a news release. Georgia departments of driver services in Chatham, Effingham. Bulloch, Liberty, Glynn and Camden counties will be closed Friday and Saturday. The agencies may decide Thursday morning to close Thursday as well. Ports in Miami, Jacksonville, Fort Lauderdale and Cape Canaveral are closed to cruise ships until further notice.

Anyone expecting to visit government and public service buildings should check for potential closures before heading out.

Matthew had already swept across a remote area of Haiti, and government leaders said they weren’t close to fully gauging its impact, The Associated Press reported. At least 11 deaths had been blamed on the storm, five of them in Haiti.

With sustained winds of 125 mph, Matthew was bearing down on the southern Bahamas Wednesday amid forecasters’ predictions it would be near Florida’s Atlantic coast by Thursday evening, according to The AP. The hurricane was spreading high winds, pounding rain and a dangerous storm surge ahead of it on its approach to the Bahamas.

By Friday night, the center of Matthew is expected to be less than 100 miles from the Georgia coast, Channel 2 meteorologist Brad Nitz said.

Georgia has not had a direct hit from a hurricane in more than a century.

RELATED: See Hurricane Matthew’s projected path.

Though he urged people not to panic, Gov. Nathan Deal declared a state of emergency Tuesday for 13 counties. Governors in three other states — Florida, South Carolina and North Carolina — also declared states of emergency and prepared evacuation plans. In Florida, mandatory evacuations were ordered in Brevard County, and voluntary evacuations were activated in St. Lucie County.

“If you’re able to go early,” Gov. Rick Scott during a Wednesday morning news conference, “leave now.” The mandatory evacuations were scheduled to begin at 3 p.m.

Deal has not issued an evacuation order but said the hurricane’s course could change at any time and force a change in that plan.

Georgia’s state of emergency includes Brantley, Bryan, Bulloch, Camden, Charlton, Chatham, Effingham, Evans, Glynn, Liberty, Long, McIntosh and Wayne counties. Coastal Georgia faces a 20 percent chance of getting hurricane force winds, a designation that applies to sustained winds of at least 74 mph, Nitz said.

Georgia Southern University in Statesboro canceled all Friday classes and events. Classes and events at Savannah Art of College and Design are canceled through Sunday.

Airports were operating as normal, according to the Federal Aviation Administration website, but Delta Air Lines warned that Matthew could affect flights going to and from Florida and parts of the Caribbean.

Delta is offering travelers change fee waivers for travel to and from Jamaica, the Bahamas, Haiti, Turks and Caicos, and the coastal United States.

Matthew could also affect the University of Georgia’s football game against the University of South Carolina on Saturday night. School officials are monitoring the weather conditions to decide if they’re going to have to move the game or cancel it.

"We are in communication with the National Weather Service, local weather authorities and the SEC regarding potential weather issues,” South Carolina school officials said on Twitter.

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National Hurricane Center 

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Other Hurricane Matthew coverage