Mexico's popular Caribbean beaches braced Thursday for a hit from Rina, downgraded from a hurricane to a tropical storm but still threatening low-lying areas with heavy rain and wind.

As the tropical storm spun toward the coast of the Yucatan Peninsula, locals scrambled to tape up windows and officials hurriedly opened emergency shelters, with palm trees flailing from Rina's powerful gusts.

Rina was packing maximum sustained winds of 95 kilometers (60 miles) per hour as it spun just 55 kilometers southwest of Cozumel, the Miami-based National Hurricane Center (NHC) said.

The storm continued to weaken before it was due to make landfall late Thursday or early Friday near hotspots on the "Mayan Riviera" such as Playa del Carmen, Cancun and Cozumel, famous for its snow-white sands and clear sea.

The storm is expected to dump heavy rain in southeastern Mexico where flooding already has left some 200,000 people homeless since last week.

Cozumel public security chief Rudy Errosa said the resort island "remained on alert" as authorities maintained mandatory evacuation orders for tourists and locals in the path of the "erratic" storm.

About 2,000 tourists left the island on Tuesday and Wednesday, and about 850 mostly North American tourists remained, he added.

Hundreds of air travelers meanwhile were stranded after Cancun's airport canceled nearly half of its 192 scheduled flights.

"We advise passengers that the Cancun airport does not operate as a shelter, (but nevertheless) request that they stay put until their flights have been confirmed," airport management said in a statement.

In Playa del Carmen, travelers seemed unfazed as they ventured out-of-doors.

"I am not scared of hurricanes. I am calm," said Canadian tourist Alan Fontaine, adding that he planned to take photographs of the storm to show the contrast between the gray sky and the turquoise water.

Local public security chief Gerardo Alanilla said 10 shelters already had 1,700 occupants and that more would be opened as needed.

The NHC's latest bulletin said the storm would continue to weaken over the next two days, perhaps even becoming a tropical depression as early as Friday.

But it warned that a storm surge could raise water levels by as much as two feet above normal tide levels along the coast, bringing with it "large and dangerous waves."

The storm was expected to dump three to six inches (eight to 15 centimeters) of rain over the eastern Yucatan Peninsula and Cozumel through Friday, with up to 10 inches in some areas.

The US State Department has warned Americans in the area to consider leaving Mexico, as flights could be disrupted once the storm bears down.

Rina is the sixth hurricane and 17th named storm of the Atlantic hurricane season, which runs from June 1 to November 30.