Current predictions show the storm will reach Jamaica and Haiti late Monday. It will then head north Tuesday and Wednesday, moving east of the Bahamas. On Thursday and Friday, it will continue heading north and move parallel to Florida's coast.
By Wednesday, Matthew will have weakened to a Category 3 with 115 mph winds and continue to lose strength each day after hitting Haiti and Cuba. On Friday, it will have weakened to a Category 2 with 105 mph winds as it moves north miles off the coast of Jacksonville, forecasters predict.
Gov. Rick Scott urged Floridians to prepare for the storm and noted how quickly it can change paths and speed.
"This storm is catastrophic, and if it hits our state, we could see impacts that we have not seen in many years," he said in a statement Sunday. "Even though the storm's projected path is just east of our state, no one should take this lightly."
Officials along the coast of Volusia County already started their preparation.
"We're trying to secure all our non-essential equipment that we can do without but today we had a really busy beach day so we're still stuck in this in-between period and don't want to be scrambling at the last minute to get ready for this hurricane," Volusia County Beach Safety Capt. Andrew Ethridge said Sunday afternoon.
He and others have been moving traffic signs, lifeguard towers and road barriers to higher ground so they won't get swept away or damaged in the storm.
"Even if it doesn't hit us directly or just goes out to sea, we expect to see some erosion, high waves and high storm surge because of the storm," Ethridge said.
After the storm moves along Florida's coast, the Carolinas are likely to take a hit if the storm continues on its projected trajectory, an 11 p.m. update shows.
Matthew, whose speed dropped from 150 mph Sunday morning to 145 mph Sunday afternoon, remained in the Caribbean Sea on Sunday. Hurricane warnings were in effect in Kingston, Port-au-Prince and Santiago de Cuba.
Forecasters said the southern portion of Haiti and the southwestern portion of the Dominican Republic could see the worst of the storm. The region is expected to see anywhere from 15 to 25 inches of rain total. Some areas could see as much as 40 inches.
Officials with Haiti's civil protection agency said there were roughly 1,300 emergency shelters across the country, enough to hold up to 340,000 people. Authorities broadcast warnings over the radio telling people to swiftly heed evacuation warnings, trying to counter a common tendency for people to try to stay in their homes to protect them during natural disasters.
"The shelters are open but I don't believe we have anyone inside them just yet," said Joseph Edgard Celestin, a spokesman for the civil protection agency.
After passing Jamaica and Haiti, Matthew was projected to reach Cuba, potentially striking on Tuesday near the U.S. Navy base at Guantanamo Bay, where authorities were evacuating non-essential personnel, including about 700 family members of those serving there.
Everyone remaining behind was being told to take shelter, said Julie Ann Ripley, a spokeswoman. There are about 5,500 people living on the base, including 61 men held at the detention center for terrorism suspects.
The Associated Press contributed to this report.Orlando Sentinel