On Friday we have a front moving off the upper South Island in the morning, before reaching the North Island during the afternoon and evening.

In the North Island we have a cloudy day, patchy rain in most western regions becomes heavy by the afternoon, with possible thunderstorms especially about the Waikato.
Heavy rain and any thunderstorms ease by evening.
Wellington sees strong to gale northerlies during the day with cloudy skies, and any spells of rain at times clear by evening.
Along the East Coast (Gisborne southwards) we see thick high cloud with gusty northwest winds, a few spells of rain at times spreading from the west afternoon onwards then clearing later in the evening.

Heayv rain develops on the West Coast of the South Island and perhaps about Nelson (more so in the west however) is accompanied by thunderstorms – though this eases in the morning to showers, as west to southwest winds pick up.
A few showers or morning spells of rain fall in Canterbury and Marlborough before clearing, then sunny areas develop with winds tending southwest for a time.
In the morning and early afternoon, NW winds about North Canterbury through to Marlborough will be quite strong with gusts to gale possible especially inland then easing. As mentioned above winds tend southwest in Canterbury but mainly up to about Banks Peninsula then dying away in the afternoon.

Showers for Southland for much of the day, winds brisk to strong from the west.
Otago sees morning showers clear then some sun develops, further showers move in again in the evening, winds brisk from the WSW during the day.

– Aaron Wilkinson & Drew Chappell, WeatherWatch.co.nz