Sunny, warm start to Autumn - with no rain relief for driest areas

Friday, 1 March 2019

The weekend's going to kick off a warm autumn for many, with hot weather picked to extend to next week.

MetService was expecting Auckland, and much of the rest of the top half of the North Island, to have daily highs in the mid-20s during Saturday and Sunday, and for the next week.

For many other areas, including Christchurch, while the weekend - or at least Saturday - may stay in the low-20s, the rest of the week looks likely to be hotter.

Mostly dry, warm weather is expected for the first week of autumn. That's not good news for drought-stricken farmers in the northwest South Island.

Topping the forecast was Blenheim, closely followed by Alexandra, both of which were expected to have a run of days with maximums in the high-20s during the next week.

* Farmers told to plan for destocking as Nelson-Tasman drought deepens

* Hot spell coming to an end with cool down for many over next two days**

Wellington also looked like it was going to be dry and sunny for the next week, although highs in the capital weren't expected to top the low 20s.

MetService said the dry, settled conditions were due to a ridge of high pressure that built over the country on Thursday and was expected to linger long into next week.

The warmer weather followed a forecast from Niwa of above average temperatures for most of the country over the next three months.

REGIONS PARCHED

While the expected warm sunshine will be welcomed by many, MetService said many parts of the country remained parched, despite some rain last weekend.

That was particularly the case for Nelson, where only about 14mm of rain was recorded at the airport for the past two months, making it the driest January and February on record for the area.

Niwa said much of the northwest of the South Island was considered to be in meteorological drought conditions, with some areas of the Tasman District considered to be in severe drought.

It was also particularly dry for much of the Kāpiti Coast through coastal Manawatu and into Whanganui and Taranaki, and in the Far North District, Niwa meteorologist Ben Noll said.

Rainfall was forecast to be normal or below normal for the whole North Island, normal or above normal in the west of the South Island, and normal elsewhere, for the next three months, Niwa said.

'Unfortunately dry spells likely to continue to start the season. It is very dry across a large portion of the country. That's going to continue in the month of March, maybe some subtle differences as we go later in the season, but certainly dry to start,' Niwa meteorologist Ben Noll said.

Perhaps the second half of March brought a slightly higher chance for unsettled weather.

Predicting the likely autumn rainfall for the top and east of the South Island was 'very tough', and there were some mixed signals, Noll said.

There were marine heatwave conditions during summer for much of the Tasman Sea, although more to the middle and west, and also just offshore to the east of the North Island south of about Gisborne, Noll said.

'This has influenced our warm temperatures on land. As an island nation, as the seas go, we go… That has certainly been a component to the warmth that we have seen, and likely the warmth that persists into the autumn season.'

Niwa said an el nino weather system had arrived in the central Pacific, although later than usual and further west than usual.

'The continuation of warmer than average sea surface temperatures in the Tasman Sea as well as a central based el nino may contribute extra warmth, moisture, and increased risk for occasional heavy rainfall events this autumn season, although long dry spells are forecast to begin the season.'

The el nino could influence New Zealand's weather from time to time over the coming three-month period. Noll said.

'Rainfall during the second half of the autumn season, maybe even the second half of March could be influenced by that el nino condition.'