The upper North Island faces the threat of severe thunderstorms and damaging tornadoes as an active system in the Tasman moves over Northland and Auckland on Friday night.
"Along with showers and strong winds, thunderstorms are in the mix as well today," MetService said on Twitter.
"These may move through with bursts of heavier rain, hail, and for Northland and Auckland, strong wind gusts."
Appearing on AM on Friday morning, MetService meteorologist Lisa Murray said an "intense pulse" is likely to hit in the evening at around 8pm.
"If that does align, there could be some intense falls, we definitely could see some really strong gusts of wind, over 110km/h... as that pulse moves through, you could see some very heavy falls, some localised downpours, and that could push across into the Bay of Plenty and Gisborne."
A severe thunderstorm watch has been issued for Northland on Friday from 8pm to midnight. MetService warned "very gusty winds" could cause structural damage and damage trees and power lines. There's also the risk of hazardous driving conditions and even the possibility of a damaging tornado.
"These thunderstorms may produce brief heavy rain, small hail, and for Auckland this evening and tonight heavy rain of 15 to 25mm/hr, strong wind gusts of 90 to 110km/h, and a chance of a small tornado," MetService said in its severe weather outlook.
"For Northland, however, there is high risk of thunderstorms, and moderate risk of severe thunderstorms with damaging wind gusts of more than 110km/h and the possibility of a damaging tornado from evening. A severe thunderstorm watch is in force."
There's also a low risk of thunderstorms over Fiordland, Southland and Clutha, and the risk increases to moderate over southern and central Fiordland and coastal Southland from the evening, with brief heavy rain and small hail.
Meanwhile, heavy snow watches and road snow warnings have been issued down south.
"We have snow coming in down [in the south], good news for the ski fields - not so good if you're trying to get around in your car," Murray told AM.
"Southland can see that snow down to 100m - that dusting of snow on the roads - and some heavy accumulations from that 300m up. As you move up the South Island, say by the time you reach the West Coast, the Westland-Buller region, we're talking about 800m, maybe even down to a dusting at 600m, for snow levels there.
"And of course, the central plateau in the North Island - probably about 1100m, by midnight tonight probably down to 1000m. So right across the country there's that call to keep up to date with the forecasts, check Waka Kotahi before you head out to make sure roads are open, and wrap up and be warm."
