'Beefy' 21-foot waves to batter New Zealand this week

A chart of the waves. Photo credit: Twitter/ NIWA weather.

South Island surfers can expect massive waves on Tuesday evening and Wednesday as the effects of wild weather in the Southern Ocean are felt in New Zealand.

The waves will hit up to 10 metres in the Southern Ocean but are expected to dissipate by the time they reach New Zealand's coast.

NIWA forecaster Chris Brandolino told Newshub the largest waves will be off the lower west coast of the South Island from Tuesday evening until midday Wednesday, reaching between 6-6.5 metres (20-21 feet).

On Thursday morning, the east of the South Island off the coast of the Otago Peninsula can expect some larger waves of their own at around 3-4 metres (10-13 feet).

Mr Brandolino said they're "certainly beefy" waves but they will also come with some chilly weather, thanks to a southerly expected to make its way across the South Island on Thursday.

New Zealand is currently heading into a period of increased wave activity, as the cooler winter months mean more unsettled weather off the coast.

While that weather may not necessarily make it over here, the waves it creates could, making for some great surfing.