The bipolar summer conditions that have delivered such incessant wet weather to the North Island and sunshine to the south may start to resemble something more normal in coming weeks.
Weatherwatch director Phil Duncan said the northern Tasman Sea came to resemble a cyclonic bowling alley over early summer, with New Zealand being hit or grazed by low pressure systems as they rolled south.
The worst of these has been ex-tropical Cyclone Hale, which has laid waste to parts of Tairāwhiti – and locals are nervously contemplating the approach of another system.
“New Zealand really has been like a traffic island in past weeks for these systems to run past. But we have also had this stream of high-pressure weather systems from Australia that have protected the lower North Island and South Island,” Duncan said.
Looking out to the end of January, weather models start to predict more stable weather as those large blocking highs come to dominate weather patterns across the entire country.
Duncan anticipates most of the North Island will turn drier than average, with the high pressure systems tending to squash out lower air pressure systems.
“It really is looking like a battle between air pressure systems and the highs are likely to win.”
Meantime, in its latest La Niña update released this week the Australian Bureau of Meteorology has highlighted that the event is continuing, albeit weakened from its peak in spring 2022.
A change towards more neutral conditions is likely to follow in February, although the agency cautions its accuracy may be lower at this time of the year.
Sea surface temperatures remain warmer than average throughout the Pacific, resulting in greater evapotranspiration, humidity, cloudiness, and rainfall.
