Cyclone Hola has formed this morning near Vanuatu as a Category 1 tropical cyclone - and one model has it tracking towards New Zealand.
Hola is over Vanuatu's Malekula island and is expected to bring heavy rain, damaging winds and rough coastal conditions to much of the country today.
Forecasts from Fiji and Vanuatu Met Services say the storm will grow to Category 2 by tomorrow.
One European model has Hola tracking west to northern New Zealand or the Tasman Sea.
However, American models consistently show the storm tracking past East Cape on Monday.
"It remains one to watch for New Zealand but for the next few days it will be Vanuatu and New Caledonia most exposed to Cyclone Hola," WeatherWatch says.
Hola is moving southwest at 8 knots and is intensifying over sea surface temperatures of 28-30C.
Vanuatu will have heavy rain today and mildly damaging winds and rough coastal conditions, especially to the west of the nation in the days ahead as Hola deepens.
Meanwhile, rain and thunderstorms may hit the North Island today.
A complex low over the North Island will likely bring rain or showers and possible thunderstorms and localised downpours to many parts today and tomorrow.
A heavy rain warning is in place for Wairarapa, including the Tararua District, from 6am to Thursday afternoon.
Up to 120mm-160mm is expected to accumulate, with up to 15-25mm an hour.
Downpours are also expected in Hawke's Bay and Taranaki, especially about Mt Taranaki.
Streams and rivers may rise rapidly, and flooding and slips are also possible, making driving conditions may be hazardous.
MetService meteorologist Brian Mercer said quite a few thunderstorms are also expected between Waikato and Manawatu.
"They should move further north into the Auckland region this afternoon and evening."
Conditions will ease over the South Island, which suffered the low yesterday.
"In the South Island it will generally be quite a nice day, with a little bit of rain in northern parts around Nelson and the Marlborough region," Mercer said.
"There is also cloud from Banks Peninsula northwards, but most of the rest of the South Island is fine this morning."
Southland and Otago will have a mostly sunny morning, then showers from early afternoon, and cloud will break to sunny spells in Canterbury this afternoon.
