Tropical Storm Ernesto was expected to become a hurricane later Monday, according to the Miami-based US National Hurricane Centre (NHC). Ernesto was located 305 kilometres east of Cabo Gracias a Dios on the Nicaraguan-Honduran border, and 655 kilometres east of Roatan, in Honduras's Bay Islands. The storm had sustained winds of up to 100 kilometres per hour with higher gusts, and was moving west at 15 kilometres per hour. Mexico's Yucatan Peninsula and Belize were on a hurricane watch. Ernesto was expected to pass north of the coast of Honduras later Monday and Tuesday, dpa quoted the NHC as saying in its latest report. "On the forecast track, the centre of Ernesto will be passing north of the coast of Honduras tonight and Tuesday and approach the east coast of the Yucatan Peninsula early Wednesday," it said. "Strengthening is forecast and Ernesto could become a hurricane by tonight." The hurricane season in the Atlantic started on June 1 and is to end November 30.