New Zealand's "chaotic" weather pattern will continue as the country enters winter.
La Niña ended during autumn and the weather pattern around New Zealand and Australia remains "neutral", which WeatherWatch says increases the chances of a chaotic pattern with pockets of extremes - as seen with the Canterbury floods.
They say this will continue through June and there will be more low pressure in the mix, although the few highs still around will bring settled periods, especially in northern and eastern areas.
The high pressure east of New Zealand may encourage some rain into the upper North Island in the second week of June, otherwise low pressure mostly in the Southern Ocean is the next main feature that will likely brush the South Island.
Rainfall is likely to be near normal in the north of the North Island and north and east of the South Island from June to August, NIWA's Seasonal Climate Outlook says. But there could be near or above-normal rainfall in the east of the North Island.
"We've got the east of the North Island for about equal chances of near-normal or above-normal rainfall, and we could be dealing with some of those plumes of moisture coming down from the north from time to time, affecting places like the east of the North Island, that's Gisborne, Hawke's Bay, down to the Wairarapa," says NIWA meteorologist Ben Noll.
NIWA says they're a slightly wetter trend than in previous seasonal outlooks they've issued, but they have just "low-medium" confidence in this due to the ENSO neutral conditions.
"We've moved out of La Niña, we're in ENSO neutral, that can contribute more variability on that seasonal time scale where other drivers that operate at a higher frequency... have their hands on the steering wheel. On a seasonal time scale, those can be a little harder to pick out," Noll says.
There is also an increased risk for flooding events, NIWA says, particularly in the east of both islands. This is due to possible periodic heavy rainfall events and the potential for atmospheric rivers of moisture to make landfall in New Zealand.
But this winter isn't likely to be particularly cold - there will be above average temperatures in the west and east of the South Island and average or near-average everywhere else, with the possibility of fewer cold spells and frosts.
"This basically suggests that for the season as a whole, when we're closing the books at the end of the season in August, it's unlikely the country will have experienced a winter that is remembered for being colder than average," Noll says.
