Thunderstorms, hail and high winds are set to hit parts of the South Island, as regions prepare to welcome a new year.
MetService said this morning a southwest flow would spread over the South Island today, bringing rapidly cooling temperatures aloft.
Rain, hail and thunderstorms were possible across areas of Canterbury, Otago, including Dunedin, as well as Southland.
New Year's Eve hotspots Queenstown and Wānaka were in for showers - possibly heavy in the afternoon - but these would clear in time for celebrations.
There was a moderate risk of thunderstorms this afternoon and evening about Canterbury south of Rakaia, Otago and inland Southland, and about the rest of Canterbury in the evening and at night.
In Dunedin, showers would develop this morning, some heavy with thunder and hail possible from afternoon before clearing tonight.
MetService advised the thunderstorms would bring brief heavy rain of 10-25mm per hour and hail mainly 10mm to 20mm wide, however there was a low risk of larger damaging hail greater than 20mm in diameter.
A few of the thunderstorms about Canterbury may be also be squally, with localised wind gusts of 100km/h.
A low risk of thunderstorms covered many other South Island areas, MetService advised.
The El Nino weather pattern has meant an unsettled summer so far, bringing swings in temperatures which spark thunderstorms and heavy rain.
MetService meteorologist Alvin Bakker told The New Zealand Herald early summer can be quite spring-like in terms of changeable weather.
“A big frontal system has moved across the country from the southwest but we’ve had a lot of warm air coming in from the tropics that is making it active and changeable.
“It’s making all of this moisture condense out and fall all over New Zealand.”
Bakker said temperatures will still be humid and sticky across parts of the country.
“It’s going to be warm to hot, quite muggy. But with the rain coming in, it may make it a little nicer temperature-wise with things cooling down a tad.”
Meanwhile, severe wind warnings are in force for inland areas of Marlborough and Canterbury north of Arthur's Pass until noon today, with severe gale northwesterlies gusting 120km/h in exposed places.
A strong wind warning is also in place for the Marlborough Sounds, Wellington and Wairarapa south of about Greytown until 2pm this afternoon.
In Wellington, high winds are disrupting flights on New Year's Eve, causing headaches for many passengers.
- additional reporting NZ Herald
