A front has parked itself over the South Island this weekend and is dumping heavy rain over the West Coast.
"The front that affected western South Island yesterday has slowed down over northern Westland and Buller. It looks set to stick around until tomorrow afternoon, when it gets taken up by the next approaching front," MetService says on Saturday.
"All of this means it's looking to be a rainy weekend for the upper South Island, with heavy rain in parts of northern Westland and Buller.
"The approaching front has plenty of juice in it, bringing possible heavy rain for Mt Taranaki and the Tararuas as it makes headway up the North Island tomorrow."
A heavy rain warning has been issued for the ranges of Buller and Westland in the area around and north of Otira.
"Rain with some heavy falls, especially from this (Saturday) evening. Expect 120-160mm of rain to accumulate during this time, with peak intensities of 10 to 20mm/h from this evening," MetService warns.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
The cloudy weather stretches up into the North Island too, with a MetService photo showing a "moody start to the first weekend in spring" in Wellington.