Weather: Rainmaker brewing over Tasman Sea, no area safe, forecasters warn
A rainmaker is brewing over the Tasman Sea, threatening to bring deluges to the upper North Island later this week.
MetService meteorologist AlainBaillie said the rain will start moving over the country late tomorrow night from the Tasman Sea.
Baillie said the storm is made up of several “complex lows”, meaning it is a large weather system stretching the length of the country with multiple “centres”.
He said it is likely most areas of the country will see at least a little bit of rain, while others will see extended drenchings.
Heavier rainfall would affect areas in the upper North Island, including Auckland, Northland, Bay of Plenty, and the Coromandel Peninsula.
“[It also means] the rain distribution differs slightly between the models, so there’s quite a bit of doubt at this stage as to where the heaviest [rain will hit],” Baillie said.
The lower half of the country is also tipped to see heavy rain as the front crosses the South Island on Thursday night.
🌬️ A vigorous sub-tropical jet stream will drive the development of a strong, slow-moving low later this week...
— NIWA Weather (@NiwaWeather) June 9, 2024
🛑 This will coincide with an atmospheric "stop sign" (blocking high pressure) east of NZ, likely leading to widespread rain, some heavy - and it may last a while... pic.twitter.com/8xCQMsDY6j
Fiordland and the south of the Westland district are first in the firing line, followed by Dunedin and North Otago.
The National Institute of Water and Atmospheric Research (Niwa) said: “A vigorous sub-tropical jet stream will drive the development of a strong, slow-moving low later this week. This will coincide with an atmospheric ‘stop sign’ [blocking high pressure] east of New Zealand, likely leading to widespread rain, some heavy - and it may last a while.”
Baillie said the rain will continue into the weekend and possibly linger into Monday and Tuesday next week.
The Tasman Sea is forecast to become more active as areas of low pressure swirl about 🍥.
— NIWA Weather (@NiwaWeather) June 9, 2024
Later this week & upcoming weekend, rain & wind may become more widespread, affecting much of the country.
Heavy rain & thunderstorms will also be a threat. pic.twitter.com/eOPCQ31r69
“There’s going to be periods of rain and showers after that main front goes through,” Baillie said.
The weather system will also push the unusually warm temperatures out to make space for chillier nights.
MetService meteorologist John Law said temperatures were “very warm for this time of year” over the last few days, but that will not last.
“We have been spoilt with some very unseasonable temperatures but it was a brief blip and we’ll be back to something much more familiar for this time of year.”
While New Zealand should expect heavy and widespread rain later in the week, Law said we are looking at a much better few days beforehand.
“[Today] and Wednesday look pretty good, with much more settled weather.
“It’s worth keeping an eye on the forecast because I think things will go downhill for the rest of the week.”