MetService meteorologist Paris Marshall said Northland is already experiencing heavy rain, including 30mm in one hour at Kaitaia around 5am.
Civil Defence Northland issued a warning to residents and holidaymakers to be prepared for more heavy rain and strong winds.
“The warning has been brought forward, with more heavy rain expected to redevelop later today, especially from Monday afternoon into the evening, with periods of intense rain and localised downpours likely. These downpours could be heavy and develop quickly in some areas.”
Motorists have been advised to slow down and watch for surface flooding, while locals have been asked to secure outdoor furniture and be ready for possible power outages.
The Civil Defence duty team is “continuing to monitor the system closely and will share updates as things develop”.
The Northland Regional Council (NRC) live monitoring showed several rivers rising quickly this morning. Gauges on the Victoria, Waitangi, Kaihū and Te Puhi rivers have recorded sharp hourly increases, reflecting the steady rain already falling across the region.
MetService warned that streams and rivers may rise rapidly, with surface flooding and slips possible.
Rainfall so far has been heaviest in the Far North and central inland areas, where NRC gauges for the past 24 hours show the highest readings for Kāeo at Bramleys (44.5mm) and Waitangi at Ōhaeawai (37mm).
Totals are expected to climb as the main rain band moves across Northland this afternoon and evening.
A strong wind watch also remains in place – the sixth for this year, with northeast winds expected to approach severe gale in exposed areas from later today. Gusty conditions may make travel more difficult, particularly on rural roads.
Marshall said Northland has already recorded gusts of up to 115km/h, with these winds expected to spread southward.
MetService’s wider warnings show that while Northland is facing a high-impact event, other regions – including parts of Tasman, Taranaki, Westland, Bay of Plenty and Gisborne/Tairāwhiti – are forecast to receive even heavier totals.
MetService describes the system as a “significant event affecting large parts of the country”. For Northland and Auckland, MetService says downpours of up to 40mm an hour are possible overnight, and residents in flood-prone areas are urged to be prepared before going to bed tonight.
Sarah Curtis is a news reporter for the Northern Advocate, focusing on a wide range of issues. She has nearly 20 years’ experience in journalism, most of which she spent reporting on the courts in Gisborne and the East Coast.