Wind blows coconut trees during the passage of Hurricane Matthew in Port-au-Prince, Haiti, Tuesday, Oct. 4, 2016. Hurricane Matthew roared into the southwestern coast of Haiti on Tuesday, threatening a largely rural corner of the impoverished country with devastating storm conditions as it headed north toward Cuba and the eastern coast of Florida. (AP Photo/Dieu Nalio Chery)
Wind blows coconut trees during the passage of Hurricane Matthew in Port-au-Prince, Haiti, Tuesday, Oct. 4, 2016. Hurricane Matthew roared into the southwestern coast of Haiti on Tuesday, threatening a largely rural corner of the impoverished country with devastating storm conditions as it headed north toward Cuba and the eastern coast of Florida. (AP Photo/Dieu Nalio Chery)
PHOTO: Dieu Nalio Chery/AP
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Story highlights

Florida governor says residents need to prepare to be hit by major hurricane

Georgia, South Carolina and North Carolina issue state of emergency declarations

Are you affected by Hurricane Matthew? If it is safe for you to do so, WhatsApp us on *+44 7435 939 154* to share your photos, experiences and video. Please tag #CNNiReport in your message.

(CNN) —  

Gas lines in Florida. Traffic jams on South Carolina highways. Tourists in North Carolina told to pack.

Hurricane Matthew’s outer bands weren’t even close to the United States on Tuesday, but the powerful storm’s potential path was already causing headaches, triggering a hurricane warning for parts of Florida.

With the Category 4 hurricane expected to brush up to the US East Coast later this week after its deadly assault on the Caribbean, state officials warned residents and visitors to start preparing for some miserable times. Up to 1 million people could face evacuation in South Carolina.

Matthew is an “extremely dangerous” storm, Florida Gov. Rick Scott said, one that made landfall in western Haiti on Tuesday morning. It then headed over eastern Cuba with winds of 140 mph, according to the National Hurricane Center, before losing some of its force. The Bahamas are next.

The forecast is that Matthew will ride along the US coast from Florida through the North Carolina Outer Banks from Thursday evening through Saturday. It could make landfall at any point and all areas should be on guard.

But the hurricane center said long-range forecasting can be imprecise.

“When a hurricane is forecast to take a track roughly parallel to a coastline, as Matthew is forecast to do … it becomes very difficult to estimate impacts this far in advance,” the center said.

Here are how Southern states are preparing for potential effects as Matthew moves north:

Florida braces for ‘direct hit’

Gov. Rick Scott told reporters Tuesday that evacuation orders could come later in the day.

“We have to be prepared for a major hurricane,” Scott said. “We have to prepare for a direct hit.”

The governor told residents along the state’s Atlantic coast: “If you are able to leave early, leave now.”

Scott plans to activate 500 additional National Guard members by Wednesday morning.

The storm has killed seven people in the Caribbean and Scott said his goal is to make sure no one dies in his state.

“If Matthew directly impacts Florida, there will be massive destruction that we haven’t seen in years,” he said.

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CNN forecasters predict the storm could hit parts of Florida starting Thursday night.

The National Hurricane Center issued advisories for parts of the Florida coast. A hurricane warning is now in effect for Lake Okeechobee and from north of Golden Beach to the Sebastian Inlet .

A hurricane watch extends from north of the Sebastian Inlet to the Volusia/Brevard county line, including Boca Raton, West Palm Beach, Fort Pierce, Vero Beach and Cape Canaveral.

A tropical storm watch has been issued from the central Florida Keys northward to Golden Beach, including Marathon Key, Miami and the Fort Lauderdale metropolitan area.

Scott declared a state of emergency for his entire state.

CNN affiliate WSVN reported long lines at gas pumps at a Costco in North Miami Beach. A reporter with the Sun Sentinel tweeted a photo of one station that had cars waiting but no gas.

Hurricane Matthew pummels Haiti

Are we prepared for a major hurricane?

Georgia

Gov. Nathan Deal has issued a state of emergency in 13 coastal counties.

“We urge residents in these areas to remain calm but vigilant as they prepare for potential impact,” Deal said.

South Carolina

South Carolina Gov. Nikki Haley, in declaring an emergency, said the state would begin medical evacuations ahead of Hurricane Matthew on Tuesday and coastal evacuations on Wednesday afternoon.

South Carolina Department of Emergency Management Director Kim Stenson said Tuesday morning that more than 1 million people might be affected by evacuation orders.

The department of transportation was already using lane reversals as traffic coming out of coastal cities like Charleston increased. Interstate 26 heading west was bumper-to-bumper Tuesday night, according to CNN affiliate WSPA and a CNN producer.

Schools and government offices in 25 counties will be closed Wednesday. Some schools will be used as evacuation shelters.

Hurricane Matthew pummels Haiti

North Carolina playing it by ear

Gov. Pat McCrory has declared a state of emergency for more than half of the state’s 100 counties.

“Many of our central and eastern counties are already saturated from storms during the past few weeks,” Emergency Management Director Mike Sprayberry said. “We are preparing for additional flooding, downed trees and widespread power outages in the coming days.”

• Gov. Pat McCrory said the forecast had changed, to North Carolina’s detriment. “What we feared is now happening in North Carolina. The (hurricane forecast) model has changed dramatically,” he said. “The immediate concern is life-threatening rain and water (from storm surge).”

CNN’s Taylor Ward, Dave Hennen, Holly Yan and Steve Visser contributed to this report.