Introduction

Introduction to Island Climate Update 126 - March 2011

El Niño/Southern Oscillation (ENSO)

• A strong La Niña exists in the equatorial Pacific region, but is showing signs of weakening. Many dynamical and statistical climate models project persistence or weakening of the event through Austral autumn 2011. A weak La Niña or ENSO neutral conditions are expected by the onset of austral winter.

• Update of tropical cyclone forecast for 2010-11 season

• Eight tropical cyclones (TCs) have occurred in the SW Pacific region this season. Normal or above normal TC occurrence is still expected for the remainder of the season. Increased activity to the west of Fiji in the Coral Sea and North Tasman region is anticipated. Risk is elevated for Papua New Guinea, the Solomon Islands, New Caledonia, Vanuatu, and New Zealand.

Multi-model Ensemble Tool for Pacific Island (METPI) rainfall and sea surface temperature forecasts

• Below normal rainfall is forecast for the Western Kiribati, Tuvalu, Tokelau, the Northern Cook Islands, the Marquesas and the Tuamotu Archipelago.
• The South Pacific Convergence Zone is expected to be displaced southwest of normal. Above normal rainfall is expected for Papua New Guinea, New Caledonia, Tonga and the Austral Islands.
• Below normal sea surface temperatures are forecast for the Marquesas, Western Kiribati and Eastern Kiribati. New Caledonia and the Austral Islands are expected to have above normal SSTs.