A wild dose of wintry weather is rocking the country, with 9500 lightning strikes overnight and heavy snowfalls in the South Island.

A brutally cold, southwesterly flow has moved in behind yesterday's front, bringing the threat of more rain, strong winds, thunderstorms and even more snow in the far south as low as 300m today.

Parts of the South Island dropped into the negatives this morning, with Alexandra sitting at a crisp -2.4C just before dawn.

Many of the South Island's alpine passes have seen more snowfall overnight, with the Crown Range Rd receiving a heavy dusting.

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The southern skifields are celebrating the early arrival of winter.

Cardrona, Coronet Peak, the Remarkables and Mt Hutt are all reporting decent amounts of snowfall. By 4.30pm yesterday 40cm had already fallen at Cardrona.


Last night's thunderstorms were mostly concentrated around the country's western areas, MetService meteorologist Peter Little said.

A plane landing in Wellington last night was struck by lightning as part of a storm that caused heavy surface flooding in parts of the capital overnight.

Westland copped the most, with 845 strikes, Buller had 432, Taranaki 337, and Wellington, which covers a much smaller land mass, 132.

There were also brief but heavy downpours, which caused flooding in places, strong wind gusts and hail.

Mt Kaukau station in Wellington recorded a wind gust of 130km/h, and another station north of the city recorded a downpour of 20mm rain in an hour. Small hail was also reported in the capital, Little said.

Auckland escaped the worst of the weather, recording 22 thunderstorms in the past 24 hours, mostly in western areas.

Several short bursts of rain in the night caused some pooling around the city.

Little said the front was this morning east of Northland and moving towards the East Cape.

In its wake would be a bitterly cold, unsettled, southwesterly flow.

"We can expect further heavy showers, gusty winds and potentially some hail today. Thunderstorms could also still affect the Auckland region through the day."

Temperatures in the far south have already plummeted, and more snow is falling on the alpine passes overnight.

"There has been some more snow on the Crown Range Rd and near the Homer Tunnel on the Milford Rd."

Milford Rd (SH94) closed overnight because of snow. The road was likely to reopen by 10am today but significant snow was forecast for the area tomorrow, which could mean an all-day closure.

Road snow warnings also remain in place for Lewis Pass (SH7), Arthurs Pass (SH73) and Crown Range Rd.

Road users are being urged to take extreme care due to the icy conditions.

Queenstown Lakes District Council said "Jack Frost has been working his mischief" and there was a high chance of ice across roads in the district.

Black ice had been reported in the Cardrona Valley and over the Lindis Pass and ice on the Crown Range, which had been gritted.

Grit trucks had been busy across the rest of the district and had gritted roads from Arrowtown through to Queenstown, up Fernhill and on Glenorchy Rd.

NZTA has issued a caution notice for black ice on SH8 between Tarras and Omarama.

Alexandra was sitting at a crisp -2.4C at 5.30am under clear skies, and Gore and Invercargill were at 4C with heavy showers and brutal southwesterlies.

Invercargill and Dunedin are in for a day of sleety showers and highs of 7C and 8C respectively. Most of the South Island will spend the day in the low teens.

"The far south can expect more snow today to 300m in Southland, so a pretty cold day," Little said.

"A taste of winter."

The North Island will be a few degrees warmer, but a sharp drop cooler than it has been, with temperatures mostly around the low to mid teens.

Auckland has a high of 17C, Hamilton 15C and Wellington 14C.

MetService meteorologist April Clark said snow showers down to 300m would continue in the far south this morning, but the weather was expected to clear this afternoon.

The showers would ease and the day would become fine with high cloud and strong, cold winds.

''Wind chill will be a factor. It's going to feel pretty blustery and cold.

''This is the first cold outbreak of the season. It's going to bring the lowest snow that we've seen so far.

''It's time to bring out your winter clothes.''

Tomorrow was expected to bring periods of rain, heavy at times, and possibly more snow down to 500m, especially about coastal Southland, Clark said.

Most of the severe weather watches and warnings have now been lifted, as the front moves away from the country today, Little said.

"The weather is looking still fairly unsettled over the next few days though, with more showers and strong winds in the west, and some of it making it over to eastern areas."

Snow hits the far south in Lumsden, as lightning and snow hits hard around the country. / Supplied by Imran Baloch

By the weekend however a ridge of high pressure is forecast to build over the country.

Today's weather

Whangārei

Showers, some heavy with possible thunderstorms and hail. Strong southwesterlies. 17C high, 9C overnight.

Auckland Showers, some heavy with possible thunderstorms and hail. Strong southwesterlies. 17C high, 9C overnight.

Hamilton Showers, some heavy with possible thunderstorms and hail. Fresh southwesterlies. 15C high, 5C overnight.

Tauranga Showers, some possibly thundery with hail, becoming less frequent from afternoon. Strong southwest change late morning. 17C high, 6C overnight.

New Plymouth Showers, some heavy with possible thunderstorms and hail, easing late. Westerlies, strong at times. 16C high, 7C overnight.

Napier Mainly fine, but one or two showers from late afternoon as northwesterlies change southwest. 17C high, 4C overnight.

Wellington​ Mainly fine, but a few showers late afternoon with a southerly change. 14C high, 6C overnight.

Nelson​ A few morning showers, then fine. Southwesterlies becoming gusty in the afternoon. 13C high, 1C overnight.

Christchurch​ Mainly fine, but a few showers from afternoon. Southwesterlies. 11C high, -1C overnight.

Dunedin​ Sleety showers, becoming less frequent in the afternoon then clearing in the evening. Southwesterlies. 8C high, 3C overnight.

Additional reporting, Otago Daily Times