Southern spring sizzle
An air flow extending from Australia on Thursday and Friday may bring near-record warmth to parts of the interior South Island, says NIWA forecaster Ben Noll. A large area of high pressure to the northwest of New Zealand will help steer this warm air across the Tasman Sea.
Maximum temperatures could be as high as 15 degrees above average across inland Otago, Southland, and Canterbury, with actual air temperatures well into the 20s.
“There is a chance that the country will observe its first 30 degree temperature of the spring, which would be the first 30 degree temperature since April,” Mr Noll said.
Current record maximum temperatures across these regions stand in the middle or upper 20s, depending on the location.
On Friday, the above average warmth is forecast to extend into the upper South Island, affecting areas in northern Canterbury, Tasman, and Marlborough.
In the North Island, the weather story is much different – temperatures are expected to be seasonably cool on Thursday before warming up a bit across the lower portion of the island on Friday.
October so far
During October, temperatures have been average or above average countrywide. The largest difference from average has been observed across the western South Island and across parts of Bay of Plenty, Waikato, and Gisborne.
The upcoming warm spell will dramatically increase October temperature anomalies across the South Island.
Right on cue for the holiday weekend, a front moves up the South Island on Saturday, bringing cloud and showers.
This front may move onto the North Island on Saturday night or Sunday, increasing the risk for cloud and showers, Mr Noll said.
On Monday, the chance for some rain is greatest across the West Coast of the South Island, with the possibility of showers persisting across the western and northern North Island.
Temperatures through the long weekend are expected to generally be average or above average, however no additional near-record warmth is expected.