Miami (CNN) -- Rina strengthened to a Category 1 hurricane off the coast of Central America on Monday, as officials in Nicaragua searched for more than two dozen missing storm evacuees.
A navy boat ferrying people between the Miskito Cays and Puerto Cabezas, on the eastern coast, was reported missing on Sunday, according to Vice Adm. Roger Gonzalez of the Nicaraguan navy. Twenty-seven people were on board, he said.
Forecasters warn that the storm will strengthen further before making landfall later this week.
Readings from a reconnaissance aircraft showed the storm had 75 mph maximum sustained winds, according to the National Hurricane Center in Miami. As of 5 p.m. ET, Rina was centered about 195 miles southwest of Grand Cayman island and 355 miles east-southeast of Chetumal, Mexico.
The storm was moving west-northwest at 3 mph, the forecast center said, and could strengthen to a Category 3 hurricane in the next 48 hours.
Earlier Monday, forecasters said Rina's projected path had shifted course, menacing Mexico with the possibility of strong winds and heavy rainfall. The storm is expected to dump between 2-4 inches of rain over the Cayman Islands.
Rina could make landfall this week in Mexico's Yucatan Peninsula -- home to Cancun and many of Mexico's top tourist spots.
"It is too early to speculate what, if any effects Rina will have on the U.S., but after the storm makes landfall in the Yucatan, the combination of land interaction and high shear that is forecast into the Gulf of Mexico is expected to weaken Rina as it begins to turn towards the northeast towards Cuba, or perhaps South Florida or the Bahamas," said CNN meteorologist Dave Hennen.
Flood-soaked Central America also braced for more rain Monday as Rina lumbered toward land.
In Nicaragua and Honduras, where flooding and mudslides have affected thousands and killed dozens of people, authorities issued alerts warning residents that more precipitation could be on the way.
October marks the end of the rainy season in the region and is when the area is most susceptible to flooding because the ground is already saturated, CNN International weather anchor Mari Ramos said.
Heavy rains have hit Honduras for several weeks, killing at least 29 people, according to government statistics.
In Guatemala, 39 people have been killed and thousands remain at risk, the state-run AGN news agency reported.
Civil protection officials in El Salvador reported 34 rain-related deaths. And Nicaragua has reported at least 12 deaths.
Journalist Samantha Lugo contributed to this report.