Heavy rain and thunderstorms lashed parts of the Cook Islands over the weekend, flooding areas around Rarotonga.

The island saw several residents experience localised flooding due to the heavy downpour, with thunderstorms threatening from above.

According to the Cook Islands Meteorology Service, Rarotonga can expect more showers and possible thunderstorms to continue during the week, with some areas on flood watch.

Cook Islands Meteorology Service director, Arona Ngari, said the southern half of the country could expect to see the most wet weather, with the northern part of the country expecting occasional showers but remaining dry and normal.

“We are expecting some showers and thunderstorms for Rarotonga, but not as many as in the last three or four days,” said Ngari.

“Thunderstorms are expected around the island … taking place on the peripheral (side) of the island.

“By the time we get to Sunday, it looks like it (the wet weather) should end.”

Over the weekend, wind gusts reached up to 34 knots or 63 kilometres per hour from the east with 56.2 millimetres of rainfall recorded on Sunday – which is the highest amount of rainfall for the month.

The level of rainfall recorded on Sunday is 26 per cent of the total average projected for December.

Apart from the heavy rain, the Cook Islands Meteorology Service also said that humidity lends itself to thunderstorm development, with a low-pressure system moving slowly across the country, with the potential for further thunderstorms.

Ngari said a low-pressure system moving across the Cook Islands is the reason that the wet weather will continue and remain for a few more days.

“Normally moisture is increased when it comes from the north, so any wind direction from the north-west, northerly, and northeast will increase the moisture level and rate of humidity.

“When this is associated with cloud, well, this will bring rain.”

Ngari warns that people living in areas prone to flooding should be mindful of heavy downpours and keep an eye on what weather warnings are to be issued from the Meteorology Service.

Ngari says that people need to be careful when experiencing wet weather as anything can happen.

“They should be worried about flooding because at times when the amount of water comes in excess of what the streams can take it normally can overflow.

“That is why people are encouraged not to throw stuff in the streams and not to block the drainage. Because that seems to be the case in the past.

“People living in wetland areas should ensure that they put proper drainage in place, to ensure water flows without any blockage.”