NIWA recorded a huge 11.82 metre wave off the coast of Banks Peninsula on Thursday morning.
Meanwhile at Tory East, which is offshore of Marlborough, the maximum recorded wave was 7.49m and at Baring Head, near Wellington, the maximum was 6.45m.
The southerly blast that hit the country overnight is generating huge swells, which are heading up the East coast of the North Island.
And they've left a mess on the southern facing coastal roads around Wellington.
"Those are big waves - big winds make big waves, simple as that," NIWA meteorologist Chris Brandolino told Morning Report.
"What's going to happen ... is over the next six to 12 hours they are going to be cruising along right in parallel to the Wairarapa coast right up to Gisborne.
"Immediate coastal areas in northern and eastern Hawke's Bay some of those waves will sneak in and there could be 5 to 6m waves early to mid afternoon.
"The waves in Cook Strait, the waves off Banks Peninsula, they'll be decreasing as the day unfolds, likewise with the wind.
"Winds will remain quite strong and gusty in Wellington this morning [Thursday[ - but eventually ease very gradually this afternoon.
"Meanwhile, Hawke's Bay will find strong gusty winds throughout much of the day and they could gust upwards of 100kmh in exposed areas. So there could be some impact such as power outages, downed tree limbs, not too dissimilar to what we say Wellington.
"Overall, once this moves off to the north and east the weather should settle down."
RNZ
