MANAGUA, Nicaragua — An unusually late-season Tropical Storm Otto swirled over the Caribbean just off Central America on Wednesday and headed toward a possible landfall as a hurricane in Nicaragua.

Heavy rains from the storm were blamed for three deaths in Panama, and officials in Costa Rica ordered the evacuation of 4,000 people from its Caribbean coast.

In addition, areas of heavy rain well to the north may trigger flooding in parts of Honduras and Belize.

Nicaragua ordered evacuations in low-lying areas of its sparsely populated Caribbean coast, an order that could cover about 7,000 people.

The country’s disaster prevention agency said classes would be canceled in the area south of the town of Bluefields, which was hit hard by Hurricane Joan in 1988.

The U.S. National Hurricane Center said the westward-moving storm had weakened slightly overnight down to tropical storm status, with winds of 70 mph. But it said the storm would likely recover hurricane force before it makes landfall Thursday.

It would be the first Atlantic tropical cyclone on record to make landfall on Thanksgiving Day, according to Weather Underground.

The storm caused heavy rains in Panama as it moved roughly parallel to that nation’s northern coast.

Jose Donderis, Panama’s civil defense director, said a landslide just west of Panama City early Tuesday trapped nine people. Seven were rescued, but two were pulled from the mud dead. In the capital, a child was killed when a tree fell on a car outside a school.

Panamanian authorities canceled school and began to release water from the locks and lakes feeding the Panama Canal. They also said the Sixaola River, which runs along the border between Panama and Costa Rica, is being monitored for potential flooding.

Costa Rica’s National Emergency Commission said it was evacuating 4,000 people from the area where the storm was expected to hit and where rivers could overflow. The effort was expected to involve evacuations by plane, boat and road in the low-lying coastal areas.

Costa Rican President Luis Guillermo Solis said Otto could damage the country’s important coffee and agriculture sectors.

“Families who live near rivers or areas of landslides: Be alert and in contact with the local emergency committees,” Guillermo Solís said in a statement.

Nicaragua also feared damage for impoverished farmers there; Otto could threaten coffee crops that are almost ready for harvest.

Otto “could seriously jeopardize food security for small-holder farmers who rely on maize, beans, cocoa, honey, coffee and livestock for their livelihoods,” said Jennifer Zapata, a regional director for Heifer International, a U.S.-based antipoverty group.

On Wednesday, the hurricane had top sustained winds of 70 mph and was moving west at 7 mph, the U.S. hurricane center said. Otto was centered about 180 miles east-southeast of Bluefields.