Sleet and snow in the South but North Island to escape the bad weather

The snow has arrived and there's more to come - at least if you're down south.

Ski resorts in the South Island are enjoying great conditions thanks to heavy snowfalls over the weekend.

Tekapo's Roundhill Ski Area(pictured) near Mt Cook will start its season on Thursday after up to one metre of snow fell on the field.

Saturday's unexpected dump of snow trapped about 50 cars on SH8 and SH80 for up to three hours, with 30 having to be towed to freedom.

Miserable weather is likely for parts of the South Island this morning with MetService issuing a severe weather watch for Central Otago, Clutha, Dunedin and Southland last night.

A cold southwest flow was expected to develop overnight as a front moved north over the island. Temperatures are expected to stay near freezing for the rest of the week.

Snow is expected down to 200m in Southland today, and heavy snow showers were possible this morning. Dunedin and Christchurch can expect rain and sleet today, while Invercargill will be hit by sleet, hail and possible thunderstorms.

MetService could not pinpoint where the snow would accumulate but said some areas could see 15cm in a couple of hours today.Road transport, livestock and powerlines would all be affected in heavy snow areas.

Meteorologist April Clark said snow levels could be as low as 100m in parts of Southland and Otago this morning."As the front moves north over the upper South Island tomorrow morning, it weakens and brings with it showers and snow down to 600 metres for a time," explained Clark.

The North Island would escape the worst of the front, with cloudy periods and a few showers expected for most places today.

A narrow ridge of high pressure will briefly push onto New Zealand on Wednesday, clearing showers for most areas and bringing fine skies to the south.

"This is good news for the ski fields but not so good for temperatures, which are expected to stay below or near zero for many inland areas through until Friday," Clark said.

"Areas along the eastern coastline may be spared the icier temperatures, though, with cloud and a few showers forecast to linger there," she added.

On Thursday, low pressure over the north Tasman Sea sinks south on Thursday, bringing periods of rain to the upper North Island through into the weekend, with scattered falls possibly spreading elsewhere from Friday onwards.

TUESDAY'S FORECAST

WHANGAREI: Cloudy periods and showers, easing in the afternoon. Southwesterlies.
High 16°C, Low 8°C

AUCKLAND: Cloudy with a few showers. Southwesterlies.
High 16°C, Low 10°C

HAMILTON: Frost or fog possible, then cloudy with showers. Southwesterly breezes.
High 15°C, Low 5°C

TAURANGA: Mostly sunny. Southwest breezes.
High 16°C, Low 6°C

NAPIER: Early cloud, then fine, cloud returning in evening. Northwesterlies turn southwest in evening.
High 17°C, Low 2°C

WELLINGTON: Morning becoming fine, a few afternoon showers. Northerlies dying out.
High 13°C, Low 5°C

CHRISTCHURCH: Rain turns to sleety showers in morning, clearing afternoon. Southwesterlies.
High 10°C, Low 0°C

DUNEDIN: Rain, snow to 200m, turn to sleety showers in morning. Southwesterlies.
High 8°C, Low 4°C