Parts of the country may be in for thunderstorms on Friday, though wet weather will be easing up for some of the hardest hit parts of the North Island.
Gisborne and Hawke's Bay, which have been hammered with rain this week, should expect to see it easing off, MetService meteorologist April Clark said.
Meanwhile Taranaki, Waitomo and Taihape areas were most likely to be experiencing thunderstorms.
The South Island was becoming "more unstable", with rain expected to hit inland, as well as some low cloud in Southland, she said.
A huge storm that knocked out power to South Australia this week is expected to cause flooding and slips when it reaches New Zealand.
The storm will have lost most of its impact by the time it reaches the country, as its low will move to the south of the country.
The part of the storm that will hit is expected to bring heavy rain which may cause flooding, MetService meteorologist Peter Little said.
"It does move through reasonably quickly on Sunday," he said.
While there would be heavy rain, it was not expected to be prolonged, so any flooding caused by it would not be serious.
Westerly winds should follow the storm, allowing eastern areas to dry up a bit.
The Fire Service went to about 20 weather-related callouts yesterday, mostly to blocked drains.
More than 200 lightning strikes were also recorded from Northland to Taranaki between 3.30pm and 4.30pm yesterday.
Main centres outlook
Whangarei: Sunny breaks with possible showers in the afternoon. Light winds. High 19C
Auckland: Showers, some possibly heavy and thundery in the afternoon. Light winds. High 18C.
Hamilton: Showers, some possibly heavy and thundery in the afternoon. Easterly breezes. High 17C
Tauranga: Rain with heavy falls. Easterly winds. High 16C
Wellington: Fine spells developing in the afternoon. Light winds. High 16C
Christchurch: Cloudy. Drizzle clearing by the afternoon. Northeast winds. High 14C
Dunedin: Mostly cloudy with possible showers. Northeasterlies. High 15C
- Source: MetService