Kiwis warned of potential thunderstorms, tornadoes overnight

MetService has issued a raft of severe thunderstorm watches across the country as a nasty front makes its way across from the Tasman Sea.

Watches are in place from Auckland down to Westland as MetService warns the west side of the country will bear the brunt of the bad weather.

Alongside thunder and lightning, the front will be bringing strong winds and possibly even tornadoes.

"A front in the Tasman Sea is expected to move across central New Zealand overnight with a band of rain and embedded thunderstorms," MetService said on its website.

"These thunderstorms will be accompanied by a short period of heavy rain, small hail, strong northwest wind gusts, and possibly a small tornado."

NIWA is warning those in Wellington to be aware of possible power outages due to the wind, which is expected to reach over 100km/h.

"Rain, lightning and strong wind gusts (100+ km/h) likely," a spokesperson said on Twitter. "Localised wind damage and power outages possible."

Further heavy wind warnings are in place for the Wairarapa.

Most of the warnings will expire early on Wednesday morning, though the warning in place for the West Coast will expire at 9pm on Tuesday.

Canterbury also has a severe weather warning in place for heavy rain, which will expire at 8pm on Tuesday.

Further south, snow is beginning to fall and chains are now required on the Crown Range.

There are warnings snow is expected on the roads on the Lewis Pass, Arthur's Pass, Porters Pass and Lindis Pass.