Forecasters on Monday said a tropical depression is likely to form in the next week from a system expected to move west, generally toward the Caribbean.

The system emerged off the coast of Africa last Wednesday and, according to an advisory from the US-based National Hurricane Center on Monday, has a 40 per cent chance of developing in the next two days and an 80 per cent chance of developing in the next seven days.

Islands of the eastern Caribbean are now within the cone of the system which at some point is expected to turn northwest.

The National Hurricane Center said a broad area of low pressure located over the central tropical Atlantic about midway between the Windward Islands and western Africa is producing a large area of disorganised showers and thunderstorms.

“Satellite data indicate that the low-level circulation continues to become better defined and, since environmental conditions are expected to remain conducive for further development, a tropical depression is likely to form within a few days,” the advisory stated.