Climate

NIWA and MetService analyses indicate 9 to 12 named tropical cyclones (TC) could occur in the Southwest Pacific basin between November 2019 and April 2020. This expectation for tropical cyclone activity is close to normal for the region, but with elevated activity east of the International Date Line especially during the late season between February and April.

Average temperatures overall with variable rainfall patterns.

For October to December, air pressure is forecast to be lower than normal in the New Zealand region, especially south of the country. This is expected to be associated with a westerly quarter air flow anomaly, particularly during November and December. Occasional easterly quarter winds are possible during October.

Variable temperature and rainfall patterns with frequent southwesterly winds.

7th-warmest winter on record and near normal rainfall

The central Pacific El Niño event that arrived in March 2019 has ended, giving way to ENSO neutral conditions, owing to cooling sea surface temperatures (SSTs) in the tropical Pacific and a neutral Southern Oscillation Index (SOI) during August.

New Zealand’s 2nd-warmest July on record.

Despite a sharp cold snap in early August, seasonal temperatures are forecast to be near average or above average for all regions of New Zealand, owing to warmer than average coastal and regional sea surface temperatures.

An unusually dry start to winter.

A weak, central Pacific El Niño continued during June as sea surface temperatures (SSTs) remained more than 0.7˚C above average (i.e. the El Niño threshold) for the fourth consecutive month.

New Zealand’s 4th-warmest autumn on record.

New Zealand’s 3rd-warmest May on record

Although El Niño is forecast to continue during the upcoming three-month period, it may weaken later in 2019. Winter temperatures are forecast to be above average in the east of the South Island and to be above average or near average in all remaining regions.