Heavy rain warning for Wellington as ‘atmospheric river’ flows across New Zealand

Bad weather hits Petone in Wellington. Photo / Daniel Bailey

Heavy rain has brought surface flooding to parts of Wellington and drivers are being urged to take care on the roads.

MetService’s orange rain warning is in place until midnight tonight, and covers the entire Wellington region from Horowhenua to the city, including the Tararua Range.

A Wellington City Council spokesperson said there is some surface flooding on the Hutt Road between Kaiwharawhara and Ngaurannga and the northbound lanes are down to one in few locations.

“Motorists are urged to take care and drive to the conditions. Council maintenance contractors are attending to these issues.”

The region can expect 100-130mm, with peak rates of up to 25mm/h.

Some large rain accumulations seen by some our rain radars in the past 24h with plenty more forecast this week.

Some top 24h rain totals from our weather stations 👇

Northland: 128mm Cape Reinga
Taranaki: 69mm Stratford
Wellington: 64mm Wainui Saddle
Westland: 81mm Franz Josef pic.twitter.com/5QjY2ocUSb

— MetService (@MetService) May 3, 2023

MetService warns this level of rain could bring floods, slips and could cause streams and rivers to rise. Driving could also be hazardous.

The rainfall has already caused the Seaview Wastewater Treatment Plant to discharge treated wastewater into the Waiwhetu Stream.

Due to heavy rainfall and high inflows, the Seaview Wastewater Treatment Plant discharged fully treated wastewater into the Waiwhetu Steam at 3:15 am this morning. Recreational water users should follow the advice of Land, Air, Water, Aotearoa (LAWA): https://t.co/fY9cCIkCEh

— Wellington Water (@WgtnWaterNZ) May 3, 2023

An atmospheric river is fuelling intense downpours on northern and western regions, and could bring more than double a month’s amount of rain.

Mōrena. Here's the last animation from above (🛰️) showing the atmospheric river flowing into NZ.

The bright, colourful cloud (🟣) indicates the most intense rain.

Also, note the lightning (⚡️). Thunderstorms that occur will enhance rainfall, increasing the risk for flooding. pic.twitter.com/epuzs2cV7a

— NIWA Weather (@NiwaWeather) May 3, 2023

The tropically charged storm is disrupting commuters in Auckland and may cause slips and flooding, as the ground is so saturated from previous rain that surface flooding is possible. However, the rain in Auckland will not reach warning levels.

The worst of the rain is expected to hit Northland, Taranaki, Nelson and northern Marlborough.