Fresh weather warnings and watches have been issued for the Bay of Plenty and Northland in addition to those already in force for the top of the South Island.

MetService said a front was expected to move eastwards across New Zealand today and early on Thursday morning.

It would be followed by a low that moved onto the North Island.

An orange heavy rain warning was issued for the Bay of Plenty east of Whakatāne from 12pm today through till early on Thursday morning.

Rainfall totals were expected to reach up to 110mm, particularly around the ranges.

“Thunderstorms possible before dawn on Thursday,” the forecaster said.

previously issued orange heavy rain warning remained in place for the ranges northwest of Motueka, running through until 8pm today.

Up to 100mm of rain were possible, with MetService saying streams and rivers may rise rapidly.

“Surface flooding, slips, and difficult driving conditions are possible.”

A heavy rain watch was also in force for the western Bay of Plenty until 1am tomorrow, alongside a previously issued watch for the Richmond and Bryant ranges in the top of the South Island.

A strong wind watch has also been issued for Northland north of Whangārei on Thursday from 3pm to 10pm, where north-west winds may reach near severe gale levels in exposed locations.

NZTA has urged caution on the Auckland Harbour Bridge this evening with wind gusts of up to 95km/h forecast.

“Oblique wind gusts of 90-95 km/h are forecast for the bridge between 8pm and 10pm tonight, triggering an amber alert,” a spokesperson said.

“There is also an amber alert in place between 2pm and 7pm tomorrow with a low risk for a red alert.”

Under a red alert, all lanes on the bridge may close.

“We don’t take the decision to lower speeds, close lanes or close the bridge lightly. Our priority is the safety of road users and the bridge structure.”

Drivers of high-sided vehicles and motorcyclists were advised to avoid the bridge and instead use the western ring route on State Highways 16 and 18.

State Highway 6 reopened through the Lower Buller Gorge between Inangahua Junction and Westport at around 3pm today.

Multiple slips closed the stretch of highway on Monday, with motorists urged to use alternative routes via Reefton, Greymouth and the Great Coast Road.

NZTA said crews had made “good progress” in clearing slips and blocked culverts.

“While the road is now safe to travel, significant work remains for the crews in clearing further debris from rivers, culverts and drains,” a spokesperson said.

“Traffic management will remain in place at a number of sites throughout the Lower Buller Gorge, and motorists are urged to take care with further rain expected in the coming days.