MetService has upgraded its rain watch in Bay of Plenty to an orange heavy rain warning.

Areas west of Whakatāne, including Rotorua, could expect 100mm to 140mm of rain in the 24 hours from midnight tonight.

Streams and rivers may rise rapidly with surface flooding, slips and difficult driving conditions possible.

Showers were expected to develop in the region this morning, turning to rain this afternoon, possibly heavy, MetService said in its latest weather update.

Northeasterlies were forecast to pick up this morning.

A heavy rain watch is in place for areas east of Whakatāne between 6am Wednesday and 11am Thursday.

Landslide risk

Given the recent weather events and subsequent rainfall over the last few weeks, Tauranga City Council said there’s an increased risk of both new landslides occurring and additional damage at sites where landslides have already occurred.

“If you learn or suspect that a landslide is occurring or is about to occur in your area evacuate immediately if it is safe to do so.

A large slip in Tauriko after last month's deluge. Photo / Screenshot / Supplied

“Seek higher ground outside the path of the landslide. Getting out of the path of a landslide or debris flow path is your best protection.”

The council advised people who felt unsafe at their property to self-evacuate to family or friends. “Take animals and any medication you may need.”

Take care driving

It asked to people “take care while driving as road conditions may be slippery”.

“Watch out for slips and fallen trees. After heavy rainfall, streams and rivers may continue to rise. If you see rising water, do not wait for official warnings. Head for higher ground and stay away from floodwater.

Flooding on Oropi Rd, Tauranga, after last month's deluge. Photo / Supplied

“With the forecast for further adverse weather later this week and into the weekend, our teams will continue to check sites daily to ensure signage and closures remain in place.”

If residents need to report an issue, they’re advised to contact Tauranga City Council on 07 577 7000 and provide the exact location.

Cyclone risk

MetService said it was also monitoring two tropical cyclones active in Pacific waters.

Spokeswoman Heather Keats told Ryan Bridge TODAY that Cyclone Vaianu, currently northwest of Fiji, is set to hit the North Island this weekend.

“As it gets upgraded, it will then drop into our neck of the woods ... it’s looking to track directly over Northland and Auckland and will have likely have quite an impact on New Zealand.”

Keats said Vaianu was currently a Category 2 storm but was likely to be upgraded to a Category 3 – or higher – by this afternoon.

“When it comes down over Northland and Auckland this weekend, it will hold its Category 2, which is highly unusual.”

Another cyclone, the Category 3 Maila, is moving slowly in the Solomon Sea, and MetService says it “won’t have any bearing on New Zealand weather”.