Climate

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.

Wet and cool for inland parts of the South Island, variable elsewhere.

A weak, central Pacific El Niño continued during April, as patterns of enhanced rainfall persisted in the vicinity of the International Dateline. More westerly quarter winds than normal. Tasman Sea surface temperatures may influence several spells of unseasonable warmth through the season, particularly in eastern areas, contributed to by frequent westerly air flows.

It was New Zealand’s equal 2nd warmest March on record.

A central Pacific El Niño event continued during March as the ocean and atmosphere remained weakly coupled. Sea surface temperatures warmed across the equatorial Pacific during March and El Niño is expected to continue during the upcoming three-month period.

Dry for most locations, drought for upper South Island

A central Pacific El Niño is now occurring as the ocean and atmosphere have been weakly coupled for a third consecutive month. Traditionally, this occurs farther east toward South America and during the early summer season. Mean temperatures are forecast to be above average for all of New Zealand.

New Zealand’s 3rd warmest January on record.

The atmospheric circulation around New Zealand is forecast to be characterised by slightly higher than normal pressure to the southwest and southeast of New Zealand and lower pressure than normal to the northeast of the country. Weak easterly-quarter air flows are favoured.

A hot airmass over New Zealand has led to SST warming of 1.0 to 2.0˚C over the last several days. A southerly change is forecast to occur from Friday into Saturday, ending the spell of unusual warmth.

Over the past several weeks, the sea surface temperatures have warmed in the New Zealand region. They are well above average in the Tasman Sea and also above average in New Zealand coastal waters.