Disclaimer: The weather forecast outlook is based on models which consider the various climate influences. These have a degree of probability and therefore some risk in the accuracy of the forecast. The development and improvement of these models is ongoing among our regional partners with the PNG National Weather Service.
At this time we can expect higher than normal rainfall over the coming months and a more likely possibility of formation of a La Niña event towards the end of this year. A La Niña will mean the need to plan for higher and more intense rainfall than normal, and associated risk of erosion, landslides, flooding and excess soil moisture which could harm susceptible crops. It is recommended that farmers prepare by choosing suitable crops, avoid or take precautions with flood and land-slip prone areas, and adopt soil conservation and drainage practices for the coming wet season.
The following is extracted from the PNG National Weather Service:
“The El Niño–Southern Oscillation (ENSO) remain neutral but the outlook is currently on the La Niña WATCH. This means that there is a fifty percent chance of La Niña after October.
Since the start of this year, all the corresponding atmospheric and oceanic indicators in the tropical pacific ocean such as the sea surface temperatures (SSTs), southern oscillation index (SOI), trade winds, and the Indian Ocean Dipole (IOD) has been consistently exhibiting a neutral ENSO conditions. Although, this trend is expected to continue for the next three months of the forecast period (July-August-September), there is an increasing possibility that after September, the situation may change to a more La Niña-like condition. This is due to the fact that, over the past month, there has been noticeable cooling observed over the tropical Pacific, especially in the eastern pacific. This cooling, is predicted to intensify after September and will be the probable trigger for the likely onset of the La Niña-like condition come October-November-December (See figure 1 and 2 below). During a La Niña-like situation, most parts of the country usually, but not always, receives above normal rainfall.
For now, the country has transitioned well into its dry season which lasts from May to October and is therefore now under the strong influence of the south easterly winds. These winds which emanates from the high pressure system over southern Australia are responsible for the transport of cold, dry, wintry air, devoid of moisture resulting in reduced rainfall as well as making our day time temperatures warmer and the night time temperatures much cooler.
Looking ahead, together with the commencement of the wet season and the increased likely of La Niña happening towards the fourth quarter of this year, there is a higher chance that the country will receive much more rainfall than it normally receives during a regular wet season, therefore the possibility of floods and landslides are possible in worst cases. Interesting times ahead so please keep a lookout.”
For more general information about climate in our region, see: