MetService meteorologist Andrew James told the Herald a clearer picture would be painted after the weekend.
"There's still plenty of uncertainty around the exact timing of impact and location of impact, so it's still a long way out," he said.
"Some computer models are indicating there is a reasonable chance the system will track southwards to the Tasman Sea.
"Effects are possible for around Aotearoa to the end of next week but it's still a long way out."
Meanwhile, a front was expected to drag a southerly change up the country tomorrow.
Strong winds and cooler air would come with the front, with a brief spell of rain for southern and central areas anticipated.
The front would then be followed by a ridge of high pressure, bringing a settled period of weather for a few days from Sunday.
"Temperatures might already feel cool for some, but this has just been a return to average after running warm for a couple of weeks," James said.
"This front briefly dips overnight low temperatures below average for some parts of the country, with the upper North Island still seeing reasonably warm days."
Most of the rain would fall in the South Island but wouldn't be prolonged as the front was due to weaken as it moved northwards.
"We don't expect anywhere north of Taupō to see any rain, so dry conditions persist for northern areas."
