Winter Climate Outlook
• A weak, central Pacific El Niño continued during May, as patterns of enhanced rainfall persisted in the vicinity of the International Dateline. Although El Niño is forecast to continue during the upcoming three-month period, it may weaken later in 2019.
• Air pressure is expected to be higher than normal to the west and north of New Zealand and lower than normal to the south, resulting in more westerly quarter winds than normal.
• 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.
• Early June will feature unsettled weather and colder than average temperatures for most of New Zealand, however, warmer than average coastal and Tasman Sea surface temperatures along with a lack of southerlies may reduce the risk for cold snaps.
• July could turn out to be a more settled month than June with an increased chance for high pressure systems to affect New Zealand.
• Rainfall is about equally likely to be below normal or near normal in the north and east of the North Island and in the north of the South Island, most likely to be near normal in the east of the South Island and west of the North Island, and about equally likely to be above normal or near normal in the west of the South Island.
• Influenced by El Niño, enhanced westerly wind flows may promote heavy rainfall events for the west of the South Island, especially since regional sea surface temperatures (SSTs) remain above average.
See the full report here.