Showers have already begun in what is expected to be two days of heavy rain and possible thunderstorms for the top half of the North Island.
Some rain alerts have been upgraded this morning as MetService forecasts up to 22 hours of rain as tropically fuelled disturbance sparks unsettled weather before the weekend.
MetService meteorologist Mmathapelo Makgabutlane said there is a low pressure system to the west of the country that was not going away.
“It is going to be bringing bands of rain over the next few days while it’s around,” she said.
🟧 Severe Weather Forecast 🟨
— MetService (@MetService) June 12, 2024
A band of heavy rain with potential for thunderstorms is heading our way.
BOP and Tasman are forecast to reach our warning criteria but areas under Watch could see a burst of heavy rain.
Get all the details here:https://t.co/HZ2TSD4U5z pic.twitter.com/MeSgG1Bojn
A heavy rain watch is forecast to come into effect for Northland from 1pm and last for 22 hours to 11am tomorrow.
The MetService says there is a moderate chance of it being upgraded to a warning.
Heavy rain watches are also coming into force for Auckland including Great Barrier Island and the Coromandel Peninsula from 8pm lasting 18 hours until 2pm tomorrow.
Rotorua and the Bay of Plenty region are now under a heavy rain warning from 3am until 8pm tomorrow.
Residents should expect between 80 to 110mm of rain to accumulate with peak rates of 15 to 25mm/h. Rates of 25 to 35mm/h are possible in localised downpours and thunderstorms.
While Taranaki is set to come under a heavy rain watch from 11pm until 7pm tomorrow. There is a moderate chance it could be upgraded to a warning.
A heavy rain watch is forecast to come into affect for Taupō from 6am to 9pm tomorrow.
Makgabutlane said even the places that are under heavy rain watches could see localised pockets of heavier rain in those areas.
Niwa said: “Two disturbances in the Tasman Sea will drag tropical moisture into New Zealand from Friday into next week.
“The combined system will produce rounds of heavy rainfall, particularly in the northern and eastern South Island, possibly swirling in the Tasman for up to a week.”
MetService meteorologist John Law said the heavy rain and possible thunderstorms would also likely bring windy conditions, “especially overnight, Thursday into Friday, into the northern areas”, Law said.
💧 From Friday into next week, two disturbances in the Tasman Sea will drag tropical moisture into New Zealand...
— NIWA Weather (@NiwaWeather) June 11, 2024
The combined system will produce rounds of heavy rainfall, particularly in the northern & eastern South Island, possibly swirling in the Tasman for up to a week! 😵💫 pic.twitter.com/yu1jtCbolL
For the South Island, heavy rain is set to come into force for Tasman from 6pm and last for 24 hours.
Expect 120 to 150mm of rain to accumulate and peak rates of 15 to 25mm/h.
MetService said there is a chance streams and rivers may rise rapidly with surface flooding, slips, and difficult driving conditions possible.