Auckland is bracing for a downpour from 5pm tonight with over 100 lightning strikes already hitting the Tasman Sea this afternoon.
WeatherWatch has forecast a "burst of downpours" moving in from the west, set to hit the North Island just south of Auckland Airport from about 4.45pm to 6pm this evening.
Isolated thunderstorms are forecast with the Pukekohe area most exposed at this stage.
The WeatherWatch lightening tracker has registered a cluster of lightening strikes just off Auckland's west coast in the Tasman Sea since 3pm today.
There will be "on again, off again" rain across the country for the coming week, but there may be some dry relief on Saturday.
Showers and rain have battered Auckland this morning, and the city was shrouded in fog for the third straight day.
The downpours have created surface flooding in some areas, making driving conditions hazardous.
MetService meteorologist Lewis Ferris said a rain band crossing the country today would clear by tonight - but temporarily.
"It's quite wet and stormy up in Auckland, there's some thunderstorm risk associated with that as it crosses over," Ferris said.
"That rain band clears the country tonight, but hangs around in western Fiordland area.
"We have the next feature that comes on tomorrow, which affects western areas of the South Island through the morning, but then moves up the country and crosses over."
Ferris said the outlook for the coming week across the country was similar to the week that has just passed.
A disturbed westerly flow over the country meant temperatures were "a little bit warmer than they typically are this time of the year".
There will be quite a lot of rain in the West, but eastern areas will stay quite dry.
"It's going to be on again, off again rain across the country through until Wednesday," Ferris said.
"Eastern areas of the South Island will be a bit dryer as they have been for the last week.
"Then moving into next week, we have a similar system that crosses on Monday and Tuesday, which is going to be quite similar. But we'll have more details as we get closer to that."
Ferris said Saturday would be the best bet for a bit of drier weather.
"They'll be showers in western areas, the eastern area will have a bit of a respite, and then it's not until Sunday that the next feature crosses over," Ferris said.
"Saturday is the best bet for the North Island. It's quite similar for the South Island in eastern areas. Saturday looks pretty good. Monday again is looking relatively dry for the North Island."
Rain developing morning, possibly heavy and thundery from afternoon, easing to a chance shower by evening. Northerlies dying out evening. 18C high, 8C overnight.
Rain developing morning, possibly heavy and thundery from afternoon, easing to a chance shower towards evening as northerlies change westerly. 16C high, 10C overnight.
Early fog. Rain from late morning, easing in the evening as northerlies die out. 15C high, 9C overnight.
Cloudy. Rain developing afternoon, easing evening then clearing. Northwest breezes. 16C high, 9C overnight.
New Plymouth Rain from about midday, possibly thundery and squally, clearing evening as strong northerlies change westerly. 15C high, 11C overnight.
Napier Cloud increasing, then some rain in the afternoon or evening. Northwest breezes. 17C high, 8C overnight.
Whanganui Becoming cloudy. Periods of rain from afternoon, easing evening as northerlies change westerly. 17C high, 11C overnight.
Wellington A morning shower or two, then rain from late afternoon to early evening. Northerlies. 13C high, 11C overnight.
Nelson Occasional rain developing late morning, chance heavy afternoon, clearing evening as northerlies tend westerly. 13C high, 4C overnight.
Christchurch Cloudy at times. Northeasterlies, strengthening for a time afternoon. 13C high, 3C overnight
Dunedin Cloudy, with early inland frosts. A few spots of afternoon rain. Becoming fine this evening. Northeasterlies dying away. 11C high, 7C overnight.