By Michael Daly of 
File image. Photo: RNZ / MARIKA KHABAZI
Heavy rain is forecast for the upper half of the North Island, and for the west of the South Island along with Tasman and Nelson.
The first of the heavy rain started falling on Saturday morning in parts of the West Coast and Tasman, and some lighter rain also fell during the morning in parts of the Auckland region and Northland.
MetService warned heavy rain could start around Mt Taranaki from 2pm Saturday and continue through the night.
In Tasman west of Motueka, rainfall intensity could get up to 25mm an hour during late afternoon and evening Saturday, with the heavy rain gone by midnight.
Auckland and Northland have a chance of heavy rain from midnight through to noon Sunday.
MetService is forecasting scattered rain through the rest of Saturday for Auckland city, with rain on Sunday morning turning to showers around midday.
Rain is expected to develop during Saturday afternoon in Wellington as northerlies strengthen, easing to showers before dawn Sunday.
Christchurch could have some brief afternoon rain Saturday, with strong northeasterlies gusting to 100kph on Banks Peninsula. Sunday's forecast is for dry weather, with afternoon sunshine.
For areas of the North Island between Auckland, Taupō and Kawerau - including Hamilton and Tauranga - periods of heavy rain are possible from 4am to 4pm Sunday.
MetService is warning of heavy rain, with possibly as much as 140mm falling in 21 hours, for the Bay of Plenty east of Kawerau and Tairāwhiti north of Ruatoria. That warning runs from midnight to 9pm Sunday, with peak rates up to 25mm an hour possible during Sunday morning and afternoon.
Severe Weather Watches and Warnings
— MetService (@MetService) August 18, 2023
The west coast of the South Island and the northern half of the North Island have a variety of Heavy Rain and Strong Wind Watches and Warnings out.
Rough details in the image, but full info is over at https://t.co/qHyE5zzql5 pic.twitter.com/iA07H2SKw2
Parts of the central North Island hill country could also have some heavy rain overnight and through Sunday morning.
Other areas with a chance of heavy rain through the rest of Saturday and into the night are Buller, the Bryan and Richmond ranges, and Fiordland north of Doubtful Sound.
Due to forecast snow, Waka Kotahi said SH94 Milford Road would be closed between Hollyford and Westgate at 4.30pm Saturday. Before then, drivers should adhere to signs telling them not to stop and as an avalanche hazard was in place.
In north Taranaki, SH3 - the coastal route - had been closed during Saturday by a slip south of Mokau. Work was under way to clear the slip, but at lunchtime Saturday Waka Kotahi was saying no detour was available and drivers should avoid the area.
* This story was first published by Stuff
