MetService National weather: December 24th - 26th.
Summer thunderstorms dumped heavy hail and torrential rain caused flash flooding this afternoon in the upper South Island.
The severe storm struck parts of the Tasman District just before 4pm, with campers on the Abel Tasman National Park and holiday hotspot Kaiteriteri in line for a direct hit.
Heavy hailblanketed Motueka, with one Motueka Valley resident saying homes had lost power as the powerful storm lashed the region.
"There'll be huge damage to any orchard in its path."
Kate Gaskell sent photos of the golden sand Tata Beach in Golden Bay being turned white as the summer holiday destination was transformed into a wintry wonderland.
Video footage showed melting hail flooding Motueka streets after the storm moved on.
Tata Beach in Golden Bay is turned into a wintry wonderland in today's hail storm. Photo / Supplied
The MetService issued a severe thunderstorm warning for parts of the Tasman District.
Thunderstorms were detected at 3.45pm near Motueka, Ngatimoti, Riwaka and Lower Moutere.
The severe thunderstorm warning was eventually lifted but a thunderstorm watch remains in place for the western Tasman Bay and Golden Bay areas till 7pm.
An unexpected hail storm turned Golden Bay's Tata Beach white this afternoon. Photo / Supplied
Meanwhile a new severe thunderstorm warning has been issued for the Gisborne and Wairoa regions.
The severe weather was detected at 7.30pm near Tiniroto, Hangaroa and Te Reinga. It was moving east and was expected to lie near Waerengaokuri, Muriwai and Waingake at 8pm, and near Gisborne Matawhero and Muriwai at 8.30pm.
The thunderstorms are likely to be accompanied by heavy rain.
Unseasonably cold temperatures can be expected throughout many parts of New Zealand this weekend as southerly winds bring rain.
Ashburton's high for today is only expected to reach 13C - 8C below average for this time of year.
And it will be a winter wonderland for the South Island, as snow is forecast to fall to 1000 metres.
A low weather system over North Canterbury this morning is expected to deepen, spreading rain and strong southerly winds over coastal parts of the region.
The heaviest rainfalls are expected about Banks Peninsula. MetService has issued a weather watch for the area, which might reach a warning level.
Generally, the weather in the South Island is the opposite from the North Island, with showery weather in the south and fine conditions in the north.
However, Northland and Auckland can expect a few morning showers before breaking out into mainly fine weather.
The Coromandel Peninsula to ManawatΕ«, including Bay of Plenty and the central high country is mainly fine, but there will be a few showers in the west.
Conditions are fine at first before showers from afternoon or evening with possible thunderstorms in Gisborne and Hawke's Bay.
There are fine spells and a few showers for Horowhenua, Kapiti, Wellington and Wairarapa. Thunderstorms are possible this morning about Wellington and Kapiti.