Tropical Storm Eta strengthened quickly Sunday as it barreled west through the Caribbean en route to Nicaragua and Honduras, which it is expected to pound with potentially deadly wind and rain, the U.S. National Hurricane Center (NHC) said.

Eta is forecast to become a hurricane overnight and plow into the northeast coast of Nicaragua and adjacent portions of eastern Honduras early Tuesday, the Miami-based NHC said.

Latest projections say Eta will by then be a Category 2 hurricane on the five-step Saffir-Simpson scale, blowing winds of up to 177 kph (110 mph). That is stronger than the NHC had earlier predicted.

"Once inland, Eta should quickly weaken over the mountainous terrain of Nicaragua and Honduras," the NHC said.

By midafternoon, Eta was 495 km (305 miles) east-northeast of Puerto Cabezas, Nicaragua, moving west at 24 kph (15 mph) and blowing sustained winds of 105 kph (65 mph), the NHC said.

Through Friday afternoon, Eta's rains threaten to cause serious flooding and landslides in Central America. Jamaica, southern Haiti and the Cayman Islands may also be hit.

By then, Eta is likely to have dumped 381-640 mm (15-25 inches) of rain on central and northern Nicaragua and much of Honduras, with up to 889 mm (35 inches) in some areas, the NHC said.

Nicaragua's government has issued a hurricane warning from the Honduras-Nicaragua border to Sandy Bay Sirpi. Honduras has put out a tropical storm warning from Punta Patuca to the border with Nicaragua.