Key Takeaways:
- Heavy rain warnings have been issued for Northland, Auckland, and the Coromandel Peninsula due to a strong, humid easterly flow.
- Up to 110mm of rain is expected in Northland, with northern and eastern areas possibly receiving 150mm or more.
- Auckland and the Coromandel Peninsula can expect heavy rain from early Tuesday, with totals between 80 and 120mm.
- A low of tropical origin is expected to approach the North Island on Wednesday, bringing heavy rain and strong east to northeast winds.
- Residents are advised to secure outdoor furniture, clear drains and gutters, and prepare for potential evacuations.
Introduction to the Weather Warning
Heavy rain watches have been upgraded to warnings as downpours close in on an already saturated Northland, parts of Auckland, and the Coromandel Peninsula. MetService has issued orange heavy rain warnings for Monday and Tuesday, with a strong, humid easterly flow set to deliver prolonged rain, possible severe thunderstorms, and localized downpours. The warnings come after Northland was slammed by torrential rain early on Sunday morning, causing significant flooding, slips, and road closures.
Expected Rainfall and Weather Conditions
In Northland, up to 110mm of rain is expected across a broad area between tonight and Tuesday afternoon, with northern and eastern areas possibly receiving 150mm or more. For Auckland north of the Harbour Bridge, Great Barrier Island, and the Coromandel Peninsula, heavy rain is forecast from early Tuesday, with totals generally between 80 and 120mm, but up to 140mm in eastern and higher areas. The rain is expected to be intense, with a low of tropical origin moving southeast and approaching the North Island on Wednesday, bringing heavy rain and strong east to northeast winds.
Preparations and Warnings
Civil Defence Northland is actively preparing for further heavy rain by monitoring forecasts alongside MetService and hydrologists, with planning and coordination meetings with councils and key stakeholders taking place. Residents are encouraged to secure outdoor furniture and loose items, clear drains and gutters, move valuables and vehicles away from flood-prone areas, relocate stock from low-lying land, and bring pets indoors. They are also advised to ensure they have food, water, medications, torches, and charged devices, as well as getting a grab bag and evacuation plan ready.
Previous Flooding and Damage
The recent flooding in Northland has caused significant damage, with up to 200mm of rain falling in localized areas, causing slips, road closures, and flooding. The settlement of akura was particularly affected, with flooding damaging homes and a recently renovated community hall. MetService meteorologist Devlin Lynden explained that a persistent moisture-laden easterly flow drawn down from the tropics had brought the rain to Northland, causing the air to cool and the moisture to condense and fall out as rain.
Road Closures and Rescue Efforts
The heavy rainfall has also caused significant disruptions to transportation, with State Highway 2 through the Waioweka Gorge, the main route between Gisborne and pōtiki, likely to remain closed for several weeks. The road was closed after heavy rainfall triggered dozens of slips, washed out sections of road, and forced more than 40 stranded people to be rescued by helicopter. Crews have spent the weekend clearing smaller slips to gain access to larger, more dangerous sites.
Uncertainty and Future Forecasting
The uncertainty of the situation means that there is a possibility of "significant changes" in the forecast, with MetService warning that the path and strength of the low originating from the tropics is very uncertain. The low is expected to pass over the central North Island, and may extend a trough onto the South Island, bringing heavy rain and strong winds to many northern and central parts of the country. Residents are advised to stay informed and up-to-date with the latest forecast and warnings.