The Met Office has raised the alert level to red.
It warns of periods of heavy to intense showers and/or thunderstorms are likely. Heavy/intense downpours are expected to result in street/flash flooding.
Gusty winds in excess of 65 km/hr can be expected. The risk of landslides/landslips is very high in areas so prone. Sea conditions are also likely to become occasionally rough.
"Adequate preparations should be made to safeguard life and property. If you live in areas that are susceptible to flooding, especially areas along the main river courses and tributaries, please be prepared," the statement says.
Trinidad and Tobago and Grenada are currently under a Tropical Storm Warning.