Vanuatu's tropical depression is expected to intensify as it moves southeast towards Fiji.
A low to the southeast of Santo has brought heavy rain cloud and thunder to the island group.
A strong marine warning remains in place.
A forecaster at Vanuatu's Meteorological Services, David Gibson, says people have been told to take precautions.
"At the moment, there's a tropical low just to the south east of Santo the biggest island. In the short term its moving south east and with that it creates a lot of cloud and rain mostly above the northern parts and central parts of Vanuatu, and with that we are expecting flooding as well, of low lying areas."
David Gibson
The Honolulu-based Joint Typhoon Warning Center has already indicated the strong possibility of this low system near Vanuatu becoming a cyclone.
