KINGSTON, Jamaica - Packing winds near 140 mph, Hurricane Emily began passing Jamaica on Saturday, threatening to buffet its south-coast with dangerously high gusts after ravaging Grenada.

The second major hurricane of the Atlantic season was on track to pass close to Grand Cayman Island and then smash into the Yucatan Peninsula, where Mexican officials prepared to evacuate tourists.

Grenada declared a national disaster Friday, the day after Emily's 90-mph winds tore down at least 100 homes, blasted out windows, sheared off roofs and flooded two hospitals and scores of other buildings.

At least one person was killed, when his home was buried under a landslide.

Emily's winds strengthened to 135 mph with higher gusts Friday morning, making it "a very rare Category 4 hurricane in the Caribbean Sea in the month of July," said Stacy Stewart, a meteorologist with the U.S. National Hurricane Center in Miami.

Then it weakened to 105 mph, raising hopes, before it regained strength and expanded its reach, with hurricane-force winds extending up to 70 miles (110 kilometers) from the eye, with tropical storm-force winds stretching another 150 miles (240 kilometers).

The second major hurricane of the Atlantic season came unusually early and made its presence felt from hundreds of miles (kilometers) away, unleashing heavy surf, gusty winds and torrential rains in all directions of the Caribbean.

The U.S. National Hurricane Center warned Jamaica to expect hurricane-force winds to gust along the coast and possibly sustained hurricane-force winds in the mountains, where the storm could dump up to 15 inches (38 centimeters) of rain that could burst river banks and provoke life-threatening mudslides.

The southern Dominican Republic and all of Haiti's southwest peninsula, poorer countries where people build shacks along river banks, should beware of lesser amounts of rainfall, as well as the Cayman Islands, the center said.

Emily's next direct hit, according to the hurricane center's projections, will be Mexico's Yucatan Peninsula on Sunday night.

If it continues on the same path, it will travel across the Gulf of Mexico and make landfall again Wednesday somewhere near the U.S.-Mexico border, forecasters said.

Jamaicans formed long lines at grocery stores Friday to stock up on water, canned food and batteries, only a week after doing the same for Hurricane Dennis, which washed away several homes, damaged crops and flooded roads.