Gale-force winds and heavy rain expected

File photo / NZ Herald

Gale-force winds and heavy rain are expected to lash the South Island tonight and parts of the lower North Island as the MetService issues severe weather warnings for conditions that could swell waterways and cause flooding.

High winds could also bring down trees and power lines in exposed areas of the Canterbury high country, Marlborough Sounds and Wellington, where gusts are forecast to hit 140km/h.

The MetService also warns of potential damage to insecure structures, and of hazardous driving conditions.

The bad weather is expected to extend into the central North Island.

Meanwhile, northern parts of New Zealand remain bathed in sunshine and are basking in warm temperatures which are expected to remain until the weekend.

The picture isn't so rosy down south as a front approaching from the Tasman Sea is forecast to bring heavy rain and northwest gales to the west of the South Island and alps region.

As much as 250-300mm of rain could fall in the higher parts of the alps, while 180-220mm could fall over Westland and Fiordland before the weekend.

The MetService says water levels could rapidly rise in Otago and Canterbury lakes and rivers, causing surface flooding and slips.

Later today, northwest gusts could hit 120km/h in parts of Southland, Otago and Canterbury, particularly in inland areas.

The winds move over the Cook Strait to Marlborough and Wellington tonight and to Wairarapa tomorrow, where they are forecast to last until evening.

Northern and eastern parts of the North Island will largely escape the bad weather. Temperatures in Auckland, Napier, Gisborne and Tauranga hit the mid to late 20s and could rise further on Saturday.

MetService's rain radar for Friday looks grim for much of the country.