NIWA Outlook: January-March 2014

Overview

The equatorial Pacific Ocean continued in a neutral state (neither El Niño nor La Niña) in December 2013.

International guidance indicates that ENSO-neutral conditions are very likely to persist for the next three months (January – March 2014). These ENSO-neutral conditions are also forecast to continue throughout the autumn and early winter, but El Niño development becomes increasingly likely by mid-year, reaching approximately 50 percent chance along with ENSO-neutral for July-October 2014.

For the coming three months as a whole, lower than normal pressures are forecast in the Tasman Sea, and over and north of New Zealand, while higher than normal pressures conditions are forecast to the southeast of the country. This circulation pattern is expected to be associated with a weak anomalous flow from the north-easterly quarter.

Sea surface temperatures are expected to remain above average around the whole of New Zealand for the coming three months.

Outlook Summary

January-March temperatures are most likely (50% chance) to be above average for North Island regions, and equally likely (40% chance) to be average or above average for South Island regions.

January-March rainfall is forecast to be equally likely (40% chance) to be normal or above normal in the north of the North Island, and normal or below normal in Nelson-Marlborough. In all other regions, the 3-month rainfall totals are most likely (45-50% chance) to be in the near normal category.

Soil moisture levels are most likely (40-45% chance)  to be near normal in all regions, except for Nelson/Marlborough where below normal soil moisture is most likely (45% chance).

River flows for the January-March 2014 period are most likely (45% chance) to be near normal in all regions, except for Nelson/Marlborough where river flows are equally likely (40% chance) to be normal or below normal. 

For full details see attachment.

SCO_Jan2014.docx

ENDS

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