Weather forecasters say a tropical depression north of the Pacific territory of Wallis and Futuna could become a tropical cyclone.
Terry Atalifo of the Fiji Metereorological Office said the depression is north-east of Wallis and tracking eastwards.
"We expect for this system to track just to the north of Samoa," he told Radio Australia.
"We are anticipating for this depression to most probably become a cyclone within the next 24 hours.
"The maximum category we are looking at at this stage is a category 2 with sustained winds of about 60 knots."
Mr Atalifo said they expect the system to stay "most probably" over waters to the north of Samoa, "and then it's going to track east-southeastwards so most probably it will be over waters most of the time."
Monday's forecast for Wallis and Futuna, a French territory, was rain and fresh to strong winds. Samoa was likely to begin experiencing fresh to strong winds with some rain.
There is a gale warning for shipping for the area just to the north of the depression.
© ABC 2013
16:28 EDT Hail is caused when raindrops are lifted up into the atmosphere during a thunderstorm and then supercooled by temperatures below freezing, turning them into ice balls.