A heavy rain warning has been issued for Northland. Photo: 123rf.com
A swathe of weather warnings are in force for the top of New Zealand as northern regions brace for torrential rain, gales and huge seas, with some parts at risk of flooding.
Skies are darkening and the wind ramping up as the first tropically charged storm of 2023 bears down on the top half of the North Island.
The Summer Haze concert Matakana in north Auckland, scheduled for tomorrow, has been cancelled due to the stormy weather forecast.
Organisers said they cancelled the day-long festival because the safety of crew and attendees could not be gauranteed.
Those tenting in holiday hotspots are being warned to be extra prepared for heavy rain and windy weather that is expected to kick in later tonight and, for some areas, hang around until the weekend.
A heavy rain warning has been issued for Northland from 1am Wednesday, as the subtropical low edges closer by the hour.
A heavy rain watch is in place for Bay of Plenty Thursday 3am to Friday 6am, and for Nelson from midnight Thursday for 24 hours.
A heavy rain watch for Auckland and Great Barrier from 9am tomorrow to Thursday 9am.
In Northland the rain is expected to arrive overnight and fall for 30 hours non-stop.
Meanwhile, a strong wind watch has also been issued for Auckland, Bay of Plenty, Coromandel, Great Barrier Is, Northland, Taihape, Taranaki, Taumarunui, Taupo, Waikato and Waitomo.
A gale warning is in place for Auckland's Waitematā Harbour as winds rise to 75km/h today, worsening to 85km/h west of Waiheke Island on Wednesday afternoon.
They said one international Jetstar flight from Gold Coast was diverted to Christchurch, but had now landed in Wellington.
"A subtropical low over the Tasman Sea is expected to direct a strong and moist northeast flow over central and northern New Zealand on Wednesday and Thursday, with some areas likely to receive warning amounts of rain and possible severe gale northeasterlies.
"Also note that large northeast swells could bring hazardous conditions to exposed coasts," MetService posted on its website.
"Heavy rain could cause slips, surface flooding and damage to roads. Severe gales could make driving conditions hazardous, especially for motorcycles and high-sided vehicles. Temporary structures such as tents could be affected."
A number of flights in and out of Wellington airport have been cancelled, delayed, or diverted because of cross winds.
An Air New Zealand spokesperson said the wind was flowing in two directions at different altitudes, making it difficult for arriving flights to land.
A spokesperson for Wellington Airport said some departing flights had also been cancelled today as a flow-on effect.
MetService warned the top of the country can expect to see up to 160mm of rain in a day in northern and eastern regions, while hilly areas in the east could expect up to 250mm.
It said this level of heavy rain could see streams and rivers rise rapidly and flooding and slips possible. Driving conditions might also prove hazardous in the region.
Seas are forecast to rise along the eastern coastline from Northland to Coromandel and not expected to ease until Friday.
Thames Coromandel District Council is warning the thousands of holidaymakers visiting the region to prepare for the incoming deluge.
"Hatch a wet weather plan, especially if you are camping," said Civil Defence controller Garry Towler.
"Check your tents drainage, make sure they are tied down, and have a place to go if things get uncomfortable."
Northland Civil Defence this afternoon urged people to relocate items from flood-prone areas, secure outdoor future and structures, including tents, and have supplies on hand in case of power cuts or road closures.
"This subtropical low may cause streams and rivers to rise rapidly as well as surface flooding and slips, which may impact driving conditions and lead to road closures. The strong winds may also add to these potential hazards, as strong wind gusts can damage trees, powerlines, unsecured structures, and temporary structures such as tents."
The storm is expected to bring heavy rain to the West Coast of the South Island on Thursday.
- NZ Herald/RNZ