Big swells are hitting the West Coast and MetService is warning those in and on the water to be cautious.
MetService says a large belt of winds south of Australia are generating big swells, which have already arrived in the South Island and will spread to the coasts of Wanganui and up to Taranaki by this evening.
TVNZ weather presenter Dan Corbett with the latest update. (Source: Other)
It will reach north to the most northward western coasts by midnight tonight.
MetService said in a statement the waves with the longest wavelengths will arrive first and these waves are "paticularly powerful".
Swimmers and boaties should be cautious as the water levels will drop but when the next peak arrives "it can be quite unexpected".
The swell will also rise rapidly when it arrives.
"These powerful waves could catch even the most experienced sea dwellers off guard with their long peak to lull times," the forecaster said.
SHARE ME