Fiji's Metservice says a tropical depression is now unlikely to form into a tropical cyclone near Tonga, due to cooler weather conditions.
Vavau and Haapai islands will feel the effects of the weather system of heavy rain and strong winds.
The Fiji Metservice's Duty forecaster, Amit Singh, says they had expected it to develop into a cyclone outside Tonga waters.
But cooler weather is now likely to see the tropical depression weaken, rather than intensify.
"The chances for it to develop into a cyclone is now moderate, and we don't expect it to form into a cyclone over Tonga waters. This moderate chance meaning 20 to 50 percent chance."
Amit Singh says they will continue to monitor the situation overnight.
A tropical cyclone alert for Tonga has been cancelled, but a strong wind warning remains in force for all Tonga land areas.