Significant disruptions to both power and road networks could be possible overnight, as a low-pressure system crosses over the top of the North Island.
A trough passes through tonight, followed by a gale-force south-westerlies that could rise to severe gales tomorrow for Northland, Auckland and Coromandel.
With winds up to 110km/h likely in Auckland, it could force the Harbour Bridge to close if the strong winds persist into rush hour.
Extra precautions taken by Waka Kotahi come in light of the incident last year where a gust of wind toppled two trucks travelling on the bridge, causing damage to the bridge that took weeks to fix.
Wind gusts are forecast to reach 80-90kph from the early hours of tomorrow morning through to midday.
"If the winds do arrive, drivers of high-sided vehicles and motorcyclists are encouraged to avoid the bridge and use the Western Ring Route on State Highways 16 and 18," a Waka Kotahi/NZTA spokesperson said.
The high winds could cause headaches for commuters, disrupting public transport networks, with a possible safety risk to buses on the bridge.
Power company Vector also has extra crews on standby ahead of the wild weather.
Head of Field Services, Marko Simunac says it’s hard to predict what, if any, impact the winds will have on power at this stage.
“We understand that power outages can be frustrating, and so our team will work as quickly and as safely as they can to get power back up and running if this happens.”
He says Vector crews may have to be stood down overnight if the conditions become unsafe to operate.
“We encourage Aucklanders to check their devices are charged, and keep a torch handy just in case.
“For your safety, please stay well away from downed lines and call 111 if you see any.”
A strong wind watch is in place for the upper North Island starting from 3am until 4pm tomorrow.
Power outages can be reported through the Vector outage centre on their website.