Temperatures in the South are likely to be warmer than normal for the next three months, a Niwa outlook report shows.
Niwa National Climate Centre scientists found weak La Nina conditions continued in the tropical Pacific during March, but trends in low-level winds and in subsurface ocean temperatures during the month indicated La Nina was coming to an end.
The report said even though the weather phenomenon's influence would wane over the next three months, New Zealand's regional climate over April-June 2018 was expected to be driven by the persistence of more northeasterly airflow than normal, and by the persistence of warm ocean waters that were present around the country.
"The northern Tasman Sea will remain unsettled, with lower pressures than normal, bringing the likelihood of significant rainfall events to the North Island and the upper South Island."
In inland Otago, Southland, the West Coast, and the Southern Alps and foothills, temperatures are "very likely" to be above average, the report said.
Rainfall totals, soil moisture levels and river flows are most likely to be in the near normal range.
Coastal Otago temperatures are also "very likely" to be above average, and rainfall totals are about equally likely to be in the "near normal range" or "above normal range".
Soil moisture levels and river flows are most likely to be in the near normal range.
Niwa's outlooks indicate the likelihood of climate conditions being "at, above, or below" average for the season as a whole.
The report said they were not weather forecasts. They are the result of the specialist judgement of Niwa's climate scientists, who take into account observations of atmospheric and ocean conditions and output from global and local climate models.
