Neutral conditions (neither La Niña nor El Niño) presently exist in the tropical Pacific, but an El Niño is likely by spring if present sea temperature trends continue. Over the July to September period, circulation in the New Zealand region is likely to show a transition from the present north-easterly anomalies of the recent La Nina towards a westerly flow anomaly at the end of the season as El Niño conditions settle in.
Rainfall in late winter to early spring is likely to be near normal in the north and west of the North Island, and normal or below normal in all other regions. Soil moisture levels are likely to be normal or below normal in the north and east of the South Island, and near normal elsewhere. River flows are likely to be below normal in eastern South Island, normal or below normal for Nelson/Marlborough, and near normal in other regions of New Zealand.
Sea temperatures around New Zealand are likely to be near normal for the season as a whole. Late winter temperatures are likely to be near average overall for all regions except the west and south of the South Island, where average or above average temperatures are likely. Frosts and snowfalls typical of winter and early spring will occur from time to time.
NIWA / WeatherWatch.co.nz
on 2/07/2012 4:36am
What does El Nino mean for us as we approach summer then?
on 2/07/2012 5:56am
Not a great deal really, as it needs to be strong before it has much impact. But historically they can increase our chances of a much hotter, drier, summer for eastern and inland parts of NZ – but cloudier, cooler and windier weather in the west. But far too early to know if and what its impact would be on NZ, so check back for further updates in the coming months.