21 August 2009
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
In this issue
El Niño/Southern Oscillation (ENSO)
El Niño/Southern Oscillation (ENSO)
Sea surface temperature anomalies (ºC) for July 2009 (Click for enlargement)
Mean sea surface temperatures (ºC) for July 2009. (Click for enlargement)
During July, conditions in the equatorial Tropical Pacific indicated that the ocean moved into an El Niño state, but the atmosphere has yet to respond. Sea surface temperature anomalies in the equatorial Pacific are generally positive and are broadly consistent with El Niño conditions.-
Forecast validation: May to July 2009
A region of suppressed convection was forecast in the southwest Pacific encompassing Tokelau, Tuvalu, and the Northern Cook Islands, with below average rainfall expected for those areas during May – July 2009. Near to below average rainfall was expected for Eastern Kiribati and the Marquesas. Near normal rainfall was forecast for Pitcairn Island and Samoa. Enhanced convection was forecast for Papua New Guinea and Vanuatu, Fiji, Niue, and the Southern Cook Islands, with above average rainfall. -
Soil moisture in July 2009
Estimates of soil moisture shown in the map (right) are based on monthly rainfall for one station in each country. Currently there are not many sites in the water balance model, but more stations will be included in the future.
The information displayed is based on a simple water balance technique to determine soil moisture levels. Addition of moisture to the available water already in the soil comes from rainfall, with losses via evapotranspiration. Monthly rainfall and evapotranspiration are used to determine the soil moisture level and its changes. -
Tropical rainfall and SST outlook: August to October 2009
Rainfall outlook map for August to October 2009.
Sea surface temperature outlook map for August to October 2009.
During August – October 2009, a region of suppressed convection is likely in the southwest Pacific encompassing Tokelau, the Northern Cook Islands, and the Marquesas, with below average rainfall expected for those areas. Near to below average rainfall is expected for Papua New Guinea and the Society Islands. Near normal rainfall is forecast for Niue, the Tuamotu Archipelago, New Caledonia, and Pitcairn Island.