First week of school holidays looks sunnier for southerners

Tuesday, 9 April 2019

Autumn weather doesn't stop a long line of people from queuing for a free icecream from Ben & Jerry's in Christchurch on Tuesday.

Sunny weather is on the way for much of the South Island in the run-up to Easter but it's a different story for North Islanders, thanks to a subtle shift in autumn weather patterns.

The high-pressure systems that kept much of the country dry from the new year until mid-March have slipped southwards, opening the door for cloudy, damp easterlies to flow across the North Island.

Wednesday is forecast to be a warm day in eastern parts of both islands, with maximum temperatures in the mid-20s, while more heavy rain is expected to fall on the South Island's West Coast.

A couple of cold southerly outbreaks are then expected to bring a hint of winter to the south and east of both islands on Thursday and Friday this week, and possibly also again towards the end of the weekend.

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A group enjoy icecream on the banks of the Avon River in Christchurch on Tuesday.

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In the South Island, the southerlies are followed by clearing weather early next week as anticyclones settle in over the south of the country. But further north, the easterly or southeasterly winds around the north side of the high pressure will keep cloud and showers drifting onshore well into next week, the first week of the school holidays.

Southerners have already seen frost on the ground this month and more frosts are possible in the far south over the next week.

Here are the thunderstorm risk charts for Wednesday. A moderate risk of thunderstorms extends up the west coast, with the possibility of 15 - 25 mm/hr of rain with thunderstorms, or possibly more. Get the full details at: https://t.co/BZWb7ZPiRd ^CRN pic.twitter.com/GjMyE8jfXy

— MetService (@MetService) April 9, 2019

Blue Skies Weather forecaster Tony Trewinnard said after days dominated by high pressure next week, southwesterly winds might then prevail for much of the rest of the month.

That would mean cooler, cloudier weather for southern and western districts but in the east milder temperatures by day followed by cold nights.

Next week, frosts were possible in sheltered parts of Otago and Southland, but north of Timaru there would be too much coastal cloud at night for temperatures to drop below freezing.

There were early signs winter might be notable for its cloudiness, 'rather than for temperature or rainfall', he said.

MetService meteorologist Georgina Griffiths said once Wednesday and Thursday's trough of low pressure passed through, ridges of high pressure would dominate next week.

'At this time of year that brings that potential for fog and frost in some places. But the North Island will maintain a southeasterly flow. If we look at what is more unusual, that North Island situation is.

'The southeasterly feeds in quite high latitude air over the North Island.'