Wellington has this morning been added to a severe weather watch as lines companies warn of possible outages as Cyclone Lusi heads towards New Zealand.

Wellington Electricity and Kapiti and Horowhenua lines company Electra have extra staff on call this weekend in case lines are blown down, causing power outages.

They warned people should be careful around downed lines.

Transpower is saying its equipment ''is built and maintained to hold up well in storm events''.

It did though have contingency plans this weekend, including stopping all planned work, securing and inspecting infrastructure, and having staff on stand-by in areas Lusi was likely to strike.

MetService severe weather forecaster John Law said Lusi was this morning about 900 kilometres north of Cape Reinga and moving south at 20kmh to 25kmh.

The best-guess scenario had it following a path off the west coast of the North Island before crossing the top of the South Island on Sunday, when Wellington would feel the brunt of it.

MetService has issued a severe weather watch for Auckland, Hawke's Bay, Taumaranui, Taupo, Taihape, Wellington, and Nelson.

Severe weather warnings have been issued for Northland, Auckland, Coromandel Peninsula, Bay of Plenty, Gisborne, Nelson and Marlborough.

The central plateau and Hawke's Bay could be in for strong winds and heavy rain on Sunday - particularly in the hills above Hawke's Bay.

A similar forecast was in place for other areas, such as Taumaranui and Taupo.

While Wellington would have a ''cloudy and fairly wet'' Sunday, the biggest factor would be the wind with gale-force northwesterly winds gusting ''easily'' up to 110kmh. Wellington's severe weather watch would likely be upgraded to a warning tomorrow, he said.

The Nelson region was also in for strong winds and heavy rain.

CIVIL DEFENCE GUIDE



- Develop a household emergency plan



- Get emergency survival items for your home and a portable kit



- Prepare your property for high winds



- Secure large, heavy objects and remove potential missiles



- Make sure your roof is secure



- Keep tarpaulins, boards and duct tape handy to repair windows



- Farmers should keep livestock in paddocks safe from floodwaters, landslides and downed power lines



Source: Waikato Region Civil Defence Emergency Management Group