New Zealand / Weather

Heavy rain watch as storm set to blow through 'quickly' - MetService

11:30 am on 18 May 2023

Repeated heavy rain events have hit the upper North Island this year so far. Photo: RNZ / Soumya Bhamidipati

Another unwelcome bout of bad weather is set to hit the upper North Island, starting in the Far North.

A heavy rain watch is in place for Northland, while Auckland, Coromandel and the Bay of Plenty can expect to be in the firing line later on Thursday and into Friday, with severe gale force winds forecast for some places.

The South Island's West Coast experienced its own bout of heavy overnight rain - continuing into Thursday - and there was snow in Central Otago.

Persistent rain in coastal Otago caused several rivers and streams around the Clutha District to flood.

An orange rain warning was in effect through to 2pm Thursday for eastern Otago from Oāmaru to the Clutha River-Mata Au.

Clutha District Council said it had crews working to minimise potential surface flooding, but it expected flooding to affect roads in most towns around the district.

Several local roads in Dunedin were closed due to flooding.

'Quite an active year so far'

MetService meteorologist Mmathapelo Makgabutlane told Morning Report the new system is more of the same subtropical flow Aotearoa has experienced this year.

'It does move through fairly quickly' - MetService meteorologist Mmathapelo Makgabutlane

"We've had quite an active year so far that has brought really heavy rain to the upper North Island, and that trend continues with this next system that we are expecting.

"It is coming from the subtropical regions so it is warmer as it's moving through so people will be feeling that in the temperature, but what will be most felt will be that rain as well as the wind.

"The one saving grace from this system in particular is that it does move through fairly quickly, so that means that over widespread areas probably not as much rain as we would have seen last week.

"However, that said, we do expect localised areas to still be in with a possibility of that heavier rain, especially considering the fact that we could see some potential thunderstorms embedded in that rain band."

Northland and other regions have already soaked up a lot of rain, which raises the chance of more flooding problems.

"The ground's very sodden, so it might not actually take those high rainfall accumulations that we would see to bring surface flooding."

Whangārei deputy mayor Phil Halse, who is also a retired dairy farmer, said his region had already been hammered by rain and they did not want more.

"Well, here we go again. We've been continually hit for the last six months with these heavy cyclone rains and heavy rainfall.

"Farmers and our commercial growers of fruit and horticulture are really, really suffering at the moment."

'We're playing catch-up' - Whangārei Deputy Mayor Phil Halse

Northland is still cleaning up from Cyclone Gabrielle, he said.

"At the moment our mayors in Northland have got together and just asked the government for $185 million just for road damage to repeair the roads.

"It's not improving our road network, it's just patching up what we've got.

"We're playing catch-up all the time."

Makgabutlane said that for anywhere that was already under a heavy rain watch or upgraded to a warning, "those impacts such as flooding and possible land slips are still a possibility".

As the system moves through the country it would head towards Bay of Plenty and Tai Rāwhiti, and while those areas were not under a watch, that could change, Makgabutlane said.