Cook Islands tropical depression track map. Photo: Cook Islands Meteorological Service
A category one cyclone is expected to make landfall overnight in Rarotonga and heavy rain could cause flash flooding.
Tropical Depression TD10F is moving south-west of Palmerston Island, located north-west of Aitutaki, at 28 kilometers per hour, and is building to a cyclone within the next six to 24 hours.
Gale force winds of up to 90kmh and coastal inundation warnings are in place for southern Cook Islands as well as heavy rain warnings.
Cook Islands meteorologist Tino Naea urged people to prepare and "secure their properties" for when the cyclone will make landfall in Rarotonga late evening or early morning.
Naea urged drivers to be cautious on the roads with poor visibility, thunderstorms and heavy rainfall which could lead to flash flooding in low coastal areas.
Cook Islands Emergency Management spokesperson Matt Blacka said people were aware of the warnings and were preparing.
Blacka's main concern was potential flooding impacts.
He also cautioned "damage to trees and crops and perhaps disruptions to some roads around Rarotonga depending on the high tide tonight", which is 2am local time.
"The cyclone has been tracking to its course and so far behaving," he said.
Naea expected the cyclone to "slowly die out" once it makes landfall as a category one in Rarotonga.
This is the third cyclone to pass through the Cook Islands this year.
Find more updates here from Cook Islands Meteorological Service.