Northwesterlies are expected to reach severe gale strength in areas of Wellington and the Wairarapa, tonight.
The most severe winds are expected in Wellington, where MetService says gusts of 150km/hr are likely. Winds of this strength have the potential to topple trees and power lines and damage unsecure structures.
The gales are expected to continue until about midday Thursday.
The strongest gusts are expected in Wellington and the Wairarapa south of Masterton, and about the Marlborough Sounds, from 6pm today till 9am Thursday.