NZ weather: Auckland motorists warned Harbour Bridge could close as heavy rain, gale-force winds, thunderstorms lash parts of North Island

Wild weather is on the way with parts of the North Island to get a soaking with heavy rain, thunderstorms and strong winds expected on Sunday and Monday.

MetService said a "large, deep, complex low-pressure system" is moving slowly southeast towards northern New Zealand on Sunday and Monday.  

An associated front is forecast to move slowly southwards over northern New Zealand on Monday, with heavy rain and easterly gales preceding the front. Large waves are also expected to affect the eastern coasts of the upper North Island. 

The wild weather has seen Waka Kotahi New Zealand Transport Agency issue a warning that the Auckland Harbour Bridge could close on Sunday or Monday.  

Waka Kotahi warns motorists wind gusts could reach 75-90km/h from 5pm on Sunday through to 12pm on Monday. 

"This would trigger an amber alert with the possibility of reduced speed limits and some lane closures on the bridge," Waka Kotahi said.  

Wind gusts may also reach 90-95 km/h from 2am until 10am on Monday.  

"Under a red alert, all lanes on the bridge may close," Waka Kotahi said.  

"Motorists are urged to drive to the conditions, look out for the electronic message boards which will indicate lane closures and reduced speeds and stay within their lane while travelling across the bridge. 

"Drivers of high-sided vehicles and motorcyclists are advised to avoid the Auckland Harbour Bridge and use the western ring route on State Highways 16 and 18." 

Weather warnings and watches

This has seen MetService issue several weather warnings and watches for the upper North Island.  

An orange heavy rain warning is in place for Northland from 12pm on Sunday through to 6am on Monday.  

MetService warns thunderstorms are possible on Monday morning with 120mm of rain expected at peak rates of 25mm/h on Sunday afternoon. 

A heavy rain warning is also in place for the Coromandel Peninsula from 6pm on Sunday through to 3pm on Monday. 

The forecasting agency warns the area should expect 150mm of rain at peak rates of 25mm/h with thunderstorms possible.  

The last heavy rain warning is for Tairawhiti/Gisborne from Tolaga Bay northwards from 3am to 9pm on Monday, with 150mm of rain expected at peak rates of 25mm/h.  

MetService said all the areas under an orange heavy rain warning should expect driving conditions to be "hazardous".  

"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous," MetService said.  

A heavy rain watch is also in place for Auckland, Great Barrier Island and Bay of Plenty north of Tauranga.  

MetService warns heavy rain may approach warning criteria and thunderstorms are possible on Monday.  

A strong wind watch is also in place for Auckland south of Whangaparaoa, the Kaimai Range and eastern Waikato.  

It comes after Coromandel residents were warned to brace for impact as the remnants of Cyclone Lola sweep towards New Zealand. 

Thames-Coromandel Civil Defence controller Garry Towler said this event could be significant, especially for people on the eastern side of the Coromandel. 

"There are a combination of factors that are adding to our concerns about this event," he said. 

"It is the remnants of a cyclone, we have king tides, storm surge, heavy rain, gale force winds and ongoing land instability issues as a result of [Cyclone] Gabrielle."