A moderate La Niña is well-established in the tropical Pacific, and may strengthen further through the rest of 2010, says the NIWA National Climate Centre. La Niña conditions are likely to continue through the summer of 2010–11.
Spring temperatures are likely to be above average across the whole country. However, short-term cold snaps typical of spring will still occur from time to time.
Rainfall is likely to be near normal in most regions, averaged over the three months of spring (September, October, November). The north and east of the North Island is likely to experience normal or above normal rainfalls, according to the Centre’s latest seasonal outlook.
Soil moisture levels and stream flows are likely to be near normal in all regions, on average through the spring.
The National Climate Centre’s seasonal outlook states that mean sea level pressures are likely to be above normal near New Zealand, for spring as a whole.
Overall Picture
Temperature:
Spring temperatures are likely to be above average in all regions. However, short-term cold snaps typical of spring will still occur from time to time. Sea surface temperatures are expected to be near average or above average around New Zealand over the September to November period.
Rainfall, soil moisture, and stream flows:
Rainfall is likely to be near normal in most places, but normal or above normal in the north and east of the North Island. Soil moisture levels and stream flows are likely to be near normal in all regions.