What happened in September, how our climate outlook for the previous three months turned out, global and local sea temperatures, and our outlook for October to December.
September 2011 was characterised by higher pressures than usual over the Tasman Sea and lower pressures to the south and east of the country. This pressure pattern produced more southwest winds than normal over New Zealand.
La Niña conditions are redeveloping in the tropical Pacific, and the event is expected to build through the coming spring and continue through summer. During late spring and early summer (October-December), mean sea level pressures are likely to be above normal across New Zealand, with weaker westerlies over the country, on average.
ENSO conditions in the tropical Pacific are returning to the La Niña range, and although still currently weak, are expected to continue strengthening. Mean sea level pressures are likely to be above normal across New Zealand, with weaker westerlies than normal over the country, on average. Temperatures are likely to be average or above average in all regions, while seasonal rainfall is likely to be normal or below normal in all regions.
The climate we predicted and what actually happened.
