A polar blast is set to plunge temperatures and bring snow to parts of the South Island while two days of heavy rain are now forecast for parts of the North Island. 

The string of warm days is set to end as a cold southwest change begins its journey across the country today. 

Niwa noted that while parts of the South Island will almost reach 30C today, they will then fail to reach 15C by Friday as a cold front comes through. 

MetService meteorologist Thapi Makgabutlane said the dramatic shift in weather expected over the next 24 hours brought on by a large frontal weather system. 

Apart from a change in temperatures the cold front also brings rain which is expected to reach the upper South Island overnight and then move upwards over the North Island on Friday. 

Hawke’s Bay and Gisborne are under a heavy rain watch for 44 hours, starting from 1pm Friday until 9am Sunday. 

Those on the east coast should keep an eye on the forecast as MetService said it is very likely the watch will be upgraded to an “Orange Rain Warning” when more information is available regarding duration, distribution and amounts of heavy rain. 

MetService has also issued a strong wind watch for central Aotearoa. 

Southerly winds may approach severe gale levels in exposed places of Wellington, Eastern Marlborough Sounds and the Kaikoura Coast from 2pm on Friday. 

“People are advised to take the normal precautions when there is a watch in place, such as tying down loose items and taking extra care on the roads, as some of those winds could approach severe gale, especially for spots exposed to the southerly.” 

Interisland travel is expected to be impacted this weekend as conditions in Cook Strait are forecast to deteriorate from midday Friday, with strong southerlies and large swells predicted to last until Saturday. 

There is also a possibility that southerly gales may also become severe about Wellington and Taranaki on Saturday. 

“Those strong winds are also expected to generate large wave conditions in the lower North Island on Friday, extending to the eastern North Island on Saturday, with heights of 3 to 4 metres likely. Extra care is advised if anyone is planning to be near the water over the next couple of days.” 

The rain and wind should gradually ease during Sunday as the low moves away to the east. 

“It could also bring some snowfalls to elevated parts of the South Island late Thursday into Friday. Because of the time of year and the speed with which the front is moving through, the snow is expected to be pretty brief, with very little settling on the ground.” Makgabutlane said.