Weather: 'Air pressure sandwich' to bring drier-than-average spring for farmers

It's been a challenging year for farmers, with many having battled not just drought but also flooding. 

And now, with spring on the way, farmers across much of the country are looking at drier-than-average conditions over the next month.

"What we're seeing in September is what I call an air-pressure sandwich," WeatherWatch head forecaster Philip Duncan told Newshub on Monday.

"You've got high pressure to the north of New Zealand, low pressure to the south of New Zealand and the filling in the middle is the windy westerlies," he said.

"That's what we've got coming up - drier-than-average weather for most of the North Island and for the upper half of the South Island and the eastern side of the South Island."

Duncan said Northland, in particular, was looking to be drier-than-average.

"Northland is under what we're calling the Australian high," he said.

"It was the Australian highs that brought Auckland and Northland and Waikato into drought last year - I'm not saying that's going to happen this year but we're monitoring it closely to make sure these highs don't come back again like they did last summer."

Hawke's Bay, which has only recently come out of its worst drought in recent memory, had a better chance of getting some wet weather, Duncan said, due to southerly winds forecast over the next few days, and then again next week.

"That won't be a big rainmaker but it will be enough to drive in some showers which will be helpful and welcome."

Farmers in much of the South Island can also expect relatively dry weather, though wetter-than-average weather was forecast for the southern half of the west coast, due to windy westerlies blowing it, Duncan said.

Some of that rain was expected to spillover into Southland, Otago and Canterbury, "but the further east you go the drier it gets".

Weather: 'Air pressure sandwich' to bring drier-than-average spring for farmers
Photo credit: WeatherWatch

In general, Duncan said the September forecast was "a fairly normal pattern".

"Drier than average, slightly warmer than average and plenty of early spring westerlies coming through."

He also added that although it wasn't yet certain, it was looking like there may be a La Niña weather pattern on the way later this year.

"That is good news for Auckland, it's good news for rural New Zealand in the North Island - but it's not locked in yet," Duncan said.

"For La Niña to really have an impact on New Zealand to bring us the rain we want, it's got to be a moderate to strong one.

"It's too early to lock in for our summer but having it in the mind is a good thing for a lot of farmers' confidence."