In Auckland, Saturday was anticipated to be partly cloudy with showers potential north of Whangaparāoa from the afternoon. MetService has forecast occasional rain for Sunday. Each days have been tipped to succeed in 15C and fall to 7C on the coldest.
Showers have been anticipated to linger concerning the metropolis on Monday and Tuesday earlier than drying out from Wednesday when it ought to settle into cloudy circumstances.
Nearly in every single place south of Auckland started the weekend with frosts and largely clear skies. MetService recorded sub-zero temperatures throughout the South Island this morning, falling as little as -10.7C at Mount Prepare dinner Airport.
St Arnaud dropped to -8C, Twizel to -7.7C, Dunedin Airport fell to -6.5C, Alexandra Airport to -5.2C and Christchurch Airport went to -5.1C, MetService mentioned.
MetService meteorologist Alwyn Bakker mentioned temperatures are colder than traditional for this time of 12 months on account of a “sudden stratospheric warming” (SSW) occasion – a uncommon phenomenon that has solely been noticed 3 times within the satellite tv for pc period within the Southern Hemisphere.
That is mixed with a ridge of excessive stress clearing the skies in a single day.
“So there’s quite a lot of warmth loss occurring in a single day.”
Bakker urged these travelling to the ski fields to take further care on the roads, because the decrease temperatures will trigger ice on the street to stay round for longer.
The Nationwide Institute of Water and Atmospheric Analysis (Niwa) defined the SSW occasion as an anomaly in wind patterns round Antarctica that often retains the cruel polar circumstances away from New Zealand.
“Each winter, the polar vortex varieties excessive above Antarctica within the polar stratosphere [the second-lowest layer of Earth’s atmosphere]. This 12 months, the vortex is exhibiting indicators of being disturbed,” Niwa mentioned.
“When an SSW happens, it will possibly assist to weaken or displace the polar vortex within the stratosphere, which then filters down onto the tropospheric polar vortex [at the lowest layer of Earth’s atmosphere] and influences our climate patterns.”
Raphael Franks is an Auckland-based reporter who covers breaking information. He joined the Herald as a Te Rito cadet in 2022.
