Weather: Cyclone Cody could cause flooding, power outages and challenging driving conditions

Kiwis are being warned of the potential danger Cyclone Cody could pose this weekend and early next week as it scrapes over the North Island, with flooding, power outages and challenging driving conditions all possible.

The large weather system is likely to approach New Zealand overnight Sunday and brush past the east side of the North Island over Monday. However, it's exact track is still unclear. On Thursday, MetService forecast it would make landfall over Bay of Plenty, but it's now expected to move east of the country. 

"Regardless of the track, there is high confidence of large easterly swells affecting eastern coasts of the North Island. Where the heaviest rain and strongest wind eventuates is more dependent on the track."

MetService on Friday issued a Heavy Rain Watch and a Strong Wind Watch for the 24 hours from midnight Sunday to midnight Monday. The rain watch applies to Gisborne and the Wairoa District, while those in the Bay of Plenty east of Whakatane and Gisborne north of Tokomaru Bay are told to be aware of the winds.

Waka Kotahi, the NZ Transport Agency, says people should check the forecast if they are driving this weekend and be prepared for "large swells on low-lying coastal roads, heavy rain and severe gales".

"We will be monitoring the situation closely and crews will be ready to implement any necessary road closures if the weather gets too dangerous for motorists," says national journey manager Helen Harris.

"With weather like this, we often see fallen trees, slips and debris on the roads. If the cyclone does hit the country as forecast, we can expect this to happen so people need to be prepared."

She said the driving conditions will be "challenging" so people should take extra care and avoid travelling if the weather gets really bad.

"Given strong gusts of wind are expected, people travelling in high-sided vehicles, caravans and motorcycles need to be particularly cautious and should consider delaying travel until the severe weather dies down, even if the roads are open.

"The weather can change quickly so people should check the forecast before heading out this weekend. We also encourage motorists to check our Waka Kotahi social media pages and Journey Planner webpage which is where we will provide updates about any incidents or closures on the state highway network.

"If you come across any hazards on the roads, such as fallen frees, rockfall or flooding, please report this to 0800 4 HIGHWAYS so that we can get a crew out there as quickly as possible."

WeatherWatch also says the cyclone's precise track is not yet locked in and it may not be known until Sunday how far the severe weather will reach. It notes there are estimates of 200mm of rain in the Gisborne ranges as well as forecasts of dangerous waves.

"Flooding risks and power outages are highly possible in eastern BoP, East Cape, Gisborne and maybe Hawke's Bay. Due to the uncertainty around the precise tracking the centre of Cody will make, it's harder to lock in severe risks further afield just yet.

"NZ is shaped north to south and Cody is tracking in from north to south – that means any "wiggle" or zig zag left or right (west or east) may have a significant consequence to your local forecast, especially for regions further to the west and on the margins of severe weather."

Auckland is just on the edge of the more severe weather, but could still see gale force southerlies on Monday.