Today is a significant weather day, especially for the South Island, as a wintry change sweeps northwards bringing snow down to sea level in places and heavy snow up in the mountains.

Both main islands have snow coming in the next 24 hours with heavy falls above about 300 or 400m. But flurries are possible to sea level either today or overnight tonight and into Monday across the eastern South Island and even potentially the lower North Island on Monday.

This isn’t an Antarctic blast, instead cold air from over the Southern Ocean will spread up and across the country while at the same time a small area of low pressure will form in the upper South Island/Cook Strait area. This small low will then feed more moisture into this bitterly cold southerly – and help twist the winds more southerly which makes Canterbury more exposed and makes rainfall and snowfall accumulation higher.

Milder westerlies will blow for the upper North Island but the cold front sweeps over the island during the afternoon and evening, with southerlies spreading up the island later in the day or overnight and into Monday.

Peak cold will be from Sunday PM to Monday PM across New Zealand.

We will have another update this morning with updated maps too.

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