Sport's big weekend under threat from North Island 'weather bomb'

Cameron Brown has won the Taupo Ironman 10 times. Photo / Andrew Warner.

A big weekend of sport is in jeopardy with stormy weather set to sweep across the North Island.

The Black Caps third one-day international against South Africa, the Taupo Ironman and the TV3 Derby Day are all under threat by the violent and fast-developing storm, expected to cross the North Island on Saturday.

Weatherwatch.co.nz Philip Duncan said the international cricket match at Eden Park and horse racing at Ellerslie Racecourse would be hit by gale force winds and possibly frequent showers brought in by the "weather bomb".

He said competitors at the Kellogg's Nutri-Grain Ironman New Zealand in Taupo would have to steel themselves for wind gusts of up to 120km/hr.

However, the worst of the driving rain brought by the storm would likely be over by the time the events' kicked off, he said.

Eden Park marketing manager Tracy Morgan was hopeful there would be enough breaks in the weather to allow some cricket.

"At this stage we're hoping that we'll get enough nice weather so we can still get some play in. All we can do is plan on the basis that we will get some play."

Organisers were planning to cancel or change the course of the Kellogg's Nutri-Grain Ironman New Zealand in Taupo if the weather did not clear.

And a worker at Ellerslie Auckland Racing Club said a decision on whether to postpone the TV3 Derby Day would be made at 7am tomorrow.

If winds were too strong, the event would be postponed until Sunday, she said.

"At this stage we're 99.9 per cent sure it's going to go ahead... We're hoping it will blow through overnight."

Metservice has issued a severe weather warning for most of the North Island and the top of the South Island, with heavy rain expected from Mt Taranaki to Mt Ruapehu, the ranges of eastern Bay of Plenty and Gisborne, Wellington, Wairarapa and the Kaikoura Ranges.

Gales are also forecast from Taranaki and the Waikato across to Bay of Plenty and down to Wellington as well as Buller, Nelson and Marlborough.

Vector is advising customers of the possibilities of outages as the stormy weather hits early tomorrow.

Chief executive Simon Mackenzie said crews have been put on alert and all efforts will be made to respond to outages as soon as possible.

"We do not expect too many issues but recommend that customers always be prepared for the possibility of an outage during inclement weather," he said.

WEATHER BOMB

* Due to make landfall this evening.

* Gale-force winds in much of the North Island.

* Destructive winds in some places.

* Heavy rain tomorrow.

* Clear skies and dry on Sunday in most regions.

* Big seas and hurricane-force winds offshore in Hawkes Bay and Wairarapa on Sunday.