Swathes of the South Island are waking up to bone-chilling temperatures as a cold snap sweeps over the country, with some areas plummeting to a glacial -10C.
Clear skies in the south could potentially see temperatures plunge to record lows this week, says Nava Fedaeff, a forecaster for the National Institute of Water and Atmospheric Research (NIWA).
"It's been a chilly week there so far because they've got clear skies, so all of the heat during the day escapes overnight," she explained to The AM Show on Tuesday morning.
Some areas nosedived to a frosty -8C on Tuesday, with the chilly temperatures expected to persist until Wednesday. Saint Arnaud, or Nelson Lakes, was the coldest at -7.1C, while Taumarunui was the chilliest town in the north with residents waking to a frosty -4.1C. Ashburton, Queenstown, Christchurch and Wanaka also shivered into the minuses on Tuesday morning, recording temperatures between -1C and -2C.
"But [we're nearing] the end of those cool temperatures, one of the last days. After that, we're actually switching - Mother Nature is flipping the switch and we're getting a bit warmer," Fedaeff explained.
An active subtropical jet is currently waiting in the wings, poised to stir up some wild weather for the North Island. The jet stream will bring more cloud and therefore warmer temperatures, as the overcast conditions will help to contain the daytime warmth.
"The clear days are going away. We've got more cloud moving in - a front that's going to move up the South Island later this week, bringing some active weather to the North Island," she said.
But skiing and snowboarding enthusiasts may have to postpone their trips to the mountains as the active weather will not spell more snowfall.
"Unfortunately not that much snow [is expected]. It's a subtropical air mass that's moving across the country, so it's not going to be particularly cold," she continued.
"I'd say 'harden up, put on a jacket' - it's winter, after all."
The air mass is expected to hit the North Island towards the end of this week, Fedaeff said, and will settle in on Saturday.
"Think thunderstorms, gusty winds, some heavy rainfall - and that's all thanks to that subtropical jet… but it's not going to be cold, so no snow is coming."
A handful of weather warnings have been issued by MetService for the North Island on Tuesday, with a strong wind watch in place for the Bay of Plenty east of Opotiki and Gisborne north of Ruatoria.
"Southeast winds may approach severe gale in exposed places at times," MetService warns.
North of Gisborne central is also under a heavy rain watch, with periods of significant rainfall expected throughout Tuesday morning.
Warnings for heavy rain and strong winds were issued for eastern parts of the Northland region on Monday night, with updates expected at 10am. Rainfall could cause streams and rivers to rise rapidly, MetService warns, with possible surface flooding, slips and hazardous driving conditions. Strong wind gusts could damage trees, powerlines and unsecured structures - high-sided vehicles and motorcyles are urged to take extra care on the roads.
A strong wind warning and strong wind watch were also issued for Great Barrier Island and the Coromandel Peninsula, north of Whangamata, on Monday night, with updates expected at 10am.
