Weather: Strong winds, heavy rain and snow on the way

Heavy rain, strong wind, low snow and potentially fog colours the national weather forecast for the coming days, with the South Island in line for the harshest weather.

MetService forecaster Aidan Pyselman said western parts of the South Island will be wet today, while better weather is forecast for the very top of the South Island and the North Island generally.

Heavy rain and wind warning for the lower South Island. Photo / Supplied

And while a weather system that moves northeast over New Zealand on Saturday is expected to bring heavy rain to many parts of the country, Pyselman said: "The North Island does not cop the rain like the South Island is going to cop it."

Fog and low cloud over the North Island again this morning shown in this night time enhanced satellite image, while high cloud is engulfing the South Island ahead of the next front. Fog is likely to stick around the upper North Island most of the morning. https://t.co/Yjbq0jgaoz pic.twitter.com/yhsejI4vse

— MetService (@MetService) August 4, 2022

A front sits over Southern New Zealand later tomorrow preceded by strong northwesterlies, which have prompted the issuing of a number of severe weather warnings for large parts of the South Island.

As a weather system moves in on Saturday, the heaviest rain is expected on the western coast of the South Island while the strongest winds are forecast around places like the Canterbury High Country, Southland and Otago.

Pyselman said it's possible wind warnings could be issued for areas like Marlborough, Wellington and Wairarapa as well.

The front continues to track up over the North Island late on Saturday and Sunday while at the same time a south- to southeast flow develops over the South Island, which is expected to bring cooler temperatures.

"That's where we are going to see potential rain for southern and eastern parts and some of that potential low snow for the South Island on Sunday."

Upper South Island snow accumulation for the next three days. Photo / Supplied

Pyselman said the snow could be quite widespread.

"It looks like [there could be snow in areas] from the bottom of [the] island right up into the Kaikōura Ranges ... and anywhere in between there could be some pretty low snow, but [no areas] have been pinpointed yet.

"I looks likely that we will see a decent change from these strong northwesterlies which have been pretty mild to a south-southeasterly, which is going to be pretty cold with the snow."