Lanes on the Auckland Harbour Bridge may close tomorrow morning as wind gusts of up to 90km/h threaten to hit the city during peak commuting times.

A severe thunderstorm watch has been issued for Northland from 7am tomorrow as wild weather that has battered parts of the South Island sweeps north.

NZ Transport Agency Waka Kotahi (NZTA) said drivers in Auckland should be prepared for the possibility of lane closures or reduced speeds on the bridge tomorrow morning.

Between 6am and 10am, wind gusts are forecast to hit 70-80km/h, with the potential to reach 90km/h.

The North Island gets its share of wet weather from this evening to Friday

These winds could trigger an amber alert, NZTA said.

Drivers of high-sided vehicles and motorcyclists were advised to avoid the Auckland Harbour Bridge and use the western ring route on State Highways 16 and 18 as they headed to work tomorrow.

The bridge would remain in a 4x4 configuration in the morning.

Closures or restrictions will be posted on NZTA social media channels.