A front moving up the country tonight and tomorrow is bringing rain and thunderstorms to the south.
A front is expected to move rapidly north across the lower and central South Island today, preceded by unstable westerlies.
It brings with it a risk of thunderstorms over coastal Southland, Fiordland and Westland, which may produce brief heavy rain, hail and strong winds.
The thunderstorm risk also extends over inland Southland, parts of Otago and Canterbury near the Alps and about the coast up to about Banks Peninsula, also Buller and western Nelson - but thunderstorm activity is set to ease as the front progresses further north.
Some precipitation is expected with the front, mainly for the west, while eastern areas will stay mostly dry. Some brief showers are possible though.
Road snowfall warnings are also in place for Lewis Pass (SH7), Arthur's Pass (SH73), Porters Pass (SH73), Lindis Pass (SH8), Crown Range Rd, and Milford Rd (SH94).
These snowfall warnings are in place until 10am tomorrow.
However the South Island is in store for a mainly sunny day on Thursday, with any cloud in the east and south quickly breaking away.
North Westland may have a few morning showers, which will clear then sunny areas increase. Marlborough and Nelson will see cloudy areas hang about for much of the day.
The upper North Island is in for a mix of sun and cloud, with a few showers affecting the east coast and western areas south of Taranaki for a time.
There is a mild day in store for most, with temperatures forecast above single digits everywhere but Central Otago.
On Friday a ridge of high pressure covers most of New Zealand, bringing mostly settled weather, but it will be short lived with another front hitting on Saturday.