Severe gales, heavy rain, big waves and storm surges are predicted for the weekend as a tropical cyclone heads for New Zealand.
The Ministry of Civil Defence and Emergency Management today warned that bad weather could be widespread.
"Cyclone Lusi is expected to transition into a subtropical weather system as it approaches New Zealand, but it is still expected to be a dangerous storm," Civil Defence Emergency Management director John Hamilton said.
"Severe weather is likely to affect many regions during this event, especially over the weekend, from Northland down to Canterbury."
Christchurch, which was particularly vulnerable because of its already saturated state, could be among the areas to be drenched by heavy rain.
MetService issued a severe-weather watch late this morning for the north of the North Island.
"Rain and easterly gales are expected to spread on to northern New Zealand from later Friday and southwards across the remainder of the North Island and upper South Island during Saturday," it said.
The rain was likely to be particularly heavy in Northland, Auckland and the Coromandel Peninsula. Easterly gales were also expected in those areas and could become severe.
"Also, in coastal areas from eastern Northland to western Bay of Plenty, heavy swells combined with very strong onshore winds and low atmospheric pressure could lead to large onshore waves and storm surge," MetService said.
"For the remainder of the North Island and upper South Island, expect a period of heavy rain during the weekend, especially in regions exposed to the east and northeast.
"Easterly gales are likely in most places, and the risk of these becoming severe is highest in the lee of ranges, such as the Kaimais.
"Although severe weather is likely, at this stage there is still considerable uncertainty regarding the track of the low and exact areas that will be affected."
Latest forecasts placed Lusi just west of the North Island on Saturday and across the Upper South Island on Sunday before moving away to the east on Monday.
Refining its forecast about 2pm today, MetService said the risk was high for heavy rain and severe easterly gales for Northland, Auckland and Coromandel from late Friday into Saturday.
For parts of the North Island south to Taranaki and Hawke's Bay, the risk was moderate.
On Sunday, there was a moderate risk of heavy rain for Nelson, Marlborough, Canterbury and North Otago, with a low risk for Manawatu, Wairarapa, Wellington and Buller.
A low risk was put on the prospect of severe southeast gales about Wellington, the Kapiti Coast and the Marlborough Sounds, with a moderate risk after that of severe northwest gales for the Marlborough Sounds, Wellington and Wairarapa.
By early afternoon today, Lusi was just east of Vanuatu and close to becoming a category 3 system (winds of 119kmh to 157kmh), MetService said.
It had the potential to intensify further in a favourable environment provided by warm tropical waters surrounding it.
Latest information on the cyclone was on the Fiji Meteorological Service website at www.met.gov.fj.
Lusi has already killed one person on Pentecost Island in Vanuatu, aid agencies report. The man was hit by a falling tree
Strong winds and heavy rain have affected most of Vanuatu's northern provinces.
Parts of Fiji's west are on alert for heavy rain from Lusi today.