MetService's rain radar, at about 7:30pm Saturday. Photo: Supplied/ MetService
MetService has added a yellow severe thunderstorm watch for Northland, which was already under a yellow heavy rain watch.
On Saturday night, the heavy rain watch was in place for the period until mid- Sunday afternoon.
Forecasters warned of: "periods of heavy rain, with thunderstorms and downpours possible. Amounts may approach warning criteria and possibly exceed them about isolated areas, especially in downpours."
The yellow severe thunderstorm watch added on Saturday through until about 3pm Sunday, to emphasise the risk posed by thunderstorm conditions in Northland. The storms could affect people at the top of Northland from 10pm Saturday, before spreading south to Dargaville and Whangarei by 6am Sunday.
"Downpours of 25 to 40mm per hour are possible in localised places - and may occur regardless of whether there is thunderstorm activity or not," forecasters said.
That could lead to hazardous driving conditions, poor visibility, flooding or slips.
The forecasters noted that the conditions bringing the heavy rain came with "a lot of uncertainty", and it was hard to tell how much rain could be on the way, and where it might fall.
️Rain has arrived in Northland.
— MetService (@MetService) April 26, 2025
Warm, moist air is being pulled over the country over the next couple of days by a low in the north Tasman Sea.
⛈️There is a risk of thunderstorms and downpours for the upper North Island during this time, so keep up to date with the latest… pic.twitter.com/WzCHTJRlHc
Many parts of Northland and Auckland have been hit hard by heavy rain, storms, and flooding this month, first in early April, then last week, by the rain-sodden and slow-moving ex-Tropical Cyclone Tam weather system.
Auckland and Coromandel Peninsula - and the areas surrounding them - could also have heavy rain and thunderstorms heading their way this weekend, too, MetService forecasters said.
"An active front will lie slow-moving close to the north of the North Island over the next few days... Warm, moist air is being pulled over the country ...by [the] low in the north Tasman Sea."
People are advised to stay up-to-date on the latest changes to the forecast, on MetService's watches and warnings page.
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