According to the latest news - http://www.stuff.co.nz/national/4132085/Massive-storm-heading-for-New-Zealand - a storm the size of Australia will be lurking 1000km south of New Zealand, the edges of which will bring some remarkably foul weather our way.
See also - http://www.stuff.co.nz/national/4134305/Wind-rain-bitter-cold-to-hit
The MetService has issued a Severe Weather Warning for a good chunk of the country - Wellington included.
Northwesterlies are expected to rise to gale overnight, and severe gale about Wellington, Wairarapa & Marlborough Sounds tomorrow morning, with gusts of 120kph. Winds that strong can lift roofs, topple trees and powerlines, and make driving dangerous, especially if you are on a motorbike, or driving a high-sided vehicle.
It'll be raining too, and also likely to be bitterly cold (many places are expecting snow to low levels), so keep an eye on vulnerable farm stock if you have them.
With all the rain we've had lately I'd expect a few slips around the place, so if you come across one that is causing problems, or surface flooding, don't hesitate to ring the council - 04-237-5089 (24hrs)
Take care out there!