A low-pressure system will bring a burst of rain to parts of New Zealand in the next few days ahead of a "classic spring cold front" that moves up the country this weekend.
WeatherWatch says the low will result in heavy falls on the West Coast and around the Nelson Ranges, before crossing the North Island with some localised heavy falls and moderate rainfall elsewhere.
"This is followed by a classic spring cold front that moves up New Zealand this weekend, starting with heavy West Coast rain on Saturday and falling apart over northern New Zealand on Sunday as a patchy broken-up rain band."
NIWA says the first weather system is scheduled to move in on Wednesday.
"When you're stepping outside to grab those takeaways on Wednesday evening in Auckland, you might get wet," the forecaster warned in a tweet.
MetService similarly warns of "tempestuous weather" in issuing its severe weather outlook.
"A trough moves eastwards across northern and central New Zealand during Thursday, bringing a period of rain and strong winds to many places. It is followed by southwesterlies and a brief ridge of high pressure," the outlook reads.
"An active cold front, preceded by strong and moist northwesterlies, is forecast to move northwards over the South Island from the Tasman Sea on Saturday, then weaken as it moves over the North Island on Sunday, followed by cold southwesterlies."
"Although widespread heavy snow isn't expected during the outlook period, snow may affect some of the higher South Island roads on Saturday and Sunday."
WeatherWatch says while previous springs have been "quite settled", weather patterns this year have seen the emergence of more lows, bringing wet weather into dry northern and eastern regions.
But over the rest of September, there's "more order in the chaos".
"By that we mean rather than systems coming at New Zealand from all angles, it will have more a westerly theme to it. This encourages bigger rainfall totals on the western side of New Zealand while drier and milder in the east," he said.
"New Zealand is also likely to receive an uptick in high pressure at the end of this month - and perhaps for the start of October too. October is expected to initially kick off mild with nor'westers as high pressure starts to depart New Zealand.
"Also, the spring equinox is this Thursday morning - after that point the days become longer than the nights and continue to grow longer up until late December as summer starts to move in."
