KINGSTON, Jamaica (AP) -- Hurricane Melissa intensified to Category 5 strength Monday as it neared Jamaica, where forecasters said it would unleash catastrophic flooding, multiple landslides and extensive infrastructure damage. It would be the strongest hurricane to hit the island since record keeping began in 1851.
Melissa, blamed for six deaths in the northern Caribbean as it headed toward Jamaica, is forecast to make landfall on the island on Tuesday and then Cuba later in the day before heading toward the Bahamas. It is not expected to affect the United States.
Category 5 is the highest on the Saffir-Simpson scale, with sustained winds exceeding 157 mph. Melissa would be the strongest hurricane in recorded history to directly hit the small Caribbean nation, said Jonathan Porter, chief meteorologist at AccuWeather.
Porter said that critical infrastructure, including Jamaica's main international airport and power plants, are located along the coast in the capital city here, where a storm surge of up to 13 feet was expected.
"This can become a true humanitarian crisis very quickly, and there is likely going to be the need for a lot of international support," Porter said in a phone interview.
On Monday morning, Melissa was centered about 135 miles southwest of Kingston and about 320 miles southwest of Guantanamo, Cuba, the U.S. National Hurricane Center in Miami said.
The hurricane had maximum sustained winds of 160 mph and was moving west at 3 mph, the center said.
Some areas in eastern Jamaica could see up to 40 inches of rain, while western Haiti could get 16 inches, according to the hurricane center. "Catastrophic flash flooding and numerous landslides are likely," it warned.
Mandatory evacuations were ordered in seven flood-prone communities in Jamaica, with buses ferrying people to shelter.
Hurricane deaths in Hispaniola
The slow-moving storm has killed at least three people in Haiti and a fourth person in the Dominican Republic, where another person remains missing. Two people died in Jamaica over the weekend as they cut trees ahead of the storm, according to the country's emergency management office.
"I want to urge Jamaicans to take this seriously," said Desmond McKenzie, deputy chairman of Jamaica's Disaster Risk Management Council. "Do not gamble with Melissa. It's not a safe bet."
Melissa was expected to keep dumping heavy rain over parts of Haiti as it moves northeast in upcoming days. A hurricane watch was in effect for the southeastern and central Bahamas and for the Turks and Caicos Islands.
A record storm for Jamaica
Melissa could be the strongest hurricane Jamaica has experienced in decades, said Evan Thompson, principal director at Jamaica's meteorological service. He warned that cleanup and damage assessment would be severely delayed because of anticipated landslides, flooding and blocked roads.
It would be the first time in recent history that a storm of Category 4 or higher makes landfall in Jamaica, Thompson said.
He noted that Hurricane Gilbert was a Category 3 storm when it hit the island in 1988. Hurricanes Ivan and Beryl were both Category 4, but they did not make landfall, Thompson said.
In addition to the rainfall, Melissa is likely to cause a life-threatening storm surge on Jamaica's southern coast, peaking around 13 feet above ground level, near and to the east of where the center of Melissa makes landfall, the U.S. center said.
"Don't make foolish decisions," warned Daryl Vaz, Jamaica's transport minister. "We are in a very, very serious time over the next few days."
Coto reported from San Juan, Puerto Rico.