What happened in November, how our climate outlook for the previous three months turned out, global and local sea temperatures, and our outlook for December to February.
It was a cold November across New Zealand, due to more frequent southerly winds than normal. The southerly winds were the result of much higher than usual pressures over the central and southern Tasman Sea, and lower than normal pressures east of the Chatham Islands. The higher pressures also extended across most of New Zealand, as far east as Gisborne, meaning it was also a rather dry month for many regions.
The equatorial Pacific Ocean remains warmer than normal, especially around and west of the Dateline, but the atmospheric conditions continue to be near neutral. Global guidance indicates that continuing neutral conditions are the most likely outcome over the next three months (December-February). In the New Zealand region, lower than normal pressures are expected southeast of the Chatham Islands, with enhanced south-westerly winds over New Zealand. For this tropical cyclone season (November – April), the risk of an ex-Tropical Cyclone approaching New Zealand is expected to be near normal. On average, one ex-Tropical Cyclone nears New Zealand during the season.
December-February temperatures are likely to be near average or below average in western areas of both Islands, and near average elsewhere. Sea surface temperatures around New Zealand are currently well below normal and are expected to continue below normal over the summer period. Rainfall is likely to be near normal or below normal in the north and east of the North Island, and near normal elsewhere.
A weak, short-lived El Niño was predicted for spring, since borderline El Niño conditions were evident at the end of winter. However, while the global ocean reached El Niño thresholds, the atmosphere failed to couple up, and the atmospheric system remained within neutral territory.
