A week of unseasonable warmth, humidity and sticky nights for New Zealand is set to end in a series of spring storms.
While much of the country will be warmer than average by as much as 10C - especially through the South Island’s interior - the weather is then forecast to go downhill in the days ahead.
NIWA says more "unseasonable warmth and humidity" is coming this week with 30C readings possible by Friday and the weekend. But this will be followed by heavy rain.
"Have a look at this plume of tropical moisture that will extend from Australia's Top End to Te Tai Tokerau Northland," NIWA says.
"On Friday/Saturday, it's forecast to move across the North Island, causing locally heavy rain and flash-flooding potential."
WeatherWatch says the heaviest rain will be on the West Coast and Taranaki with up to 200mm possible between Thursday to Sunday. Windy weather will also push through with gales in coastal and mountainous areas.
Then on Sunday a Southern Ocean southerly will reset temperatures to normal or even below-normal.
"In New Zealand those most impacted by the cooler air will be in the lower South Island this weekend and again early next week too," WeatherWatch says.
"Overnight lows next week in southern New Zealand will be closer to freezing for a time inland. Northern New Zealand will see a few degrees drop but nothing too major."
