MIAMI - Forecasters say Tropical Storm Rina has formed in the Caribbean Sea off the coasts of Honduras and Nicaragua and could become a hurricane by Tuesday.

The U.S. National Hurricane Center reports Monday that the storm's centre is located about 305 kilometres southwest of Grand Cayman.

It has maximum sustained winds of 72 kph and is moving northwest near 9 kph.

Forecasters expect Rina to gain strength in the next two days and say it could become a hurricane by Tuesday night. The storm is forecast to bring at least 2.5 centimetres of rain along the northeast coast of Honduras and more than 6 centimetres over the Cayman Islands.