Early Warning Status: October 2020

Submitted by Sylver Yagi on Tue, 10/27/2020 - 11:18

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. All key indicators of the El Niño–Southern Oscillation (ENSO) have now reached or exceed La Niña thresholds. The ENSO Outlook has been moved to La Niña (http://www.bom.gov.au/climate/enso/outlook/). The Australian Bureau of Meteorology advises that all the climate models surveyed indicate further cooling is likely, and that La Niña thresholds will likely be sustained at least into January 2021.

A La Niña brings 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.

lanina watch September 2020 OND

The following is extracted from the PNG National Weather Service:

“We have been closely monitoring and anticipating this La Niña since March this year and is finally here. It was officially declared by the Australian Bureau of Meteorology on 29 September 2020. Generally, during La Niña events, most parts of the country tend to receive more rainfall than usual so the expectations for floods and other heavy rainfall related disasters in flood-prone areas such as the highlands and low-lying areas are there. Interestingly, a smaller segments of the country tend to respond differently to La Niña, that is, they receive less rainfall and therefore tend to be drier. These include the New Guinea Islands, parts of Milne Bay and parts of the Western province.

The tropical cyclone season for PNG coincides with our regular wet season, which is from November to April each year. On average, PNG receives 1 tropical cyclone per season; however, during La Niña events, the chances of tropical cyclone increases with more than 1 tropical cyclone forming in our waters. Our tropical cyclone prone province is Milne Bay and so responsible authorities in Milne Bay province must be made aware of such risks so appropriate planning can take place now to avoid disasters.

Once formed, La Niña can lasts for 7 months or more depending on the strength of the event. The current assessment shows that this La Niña event will be a short-lived event and with the possibility of ending by the first quarter of 2021. For now, the country is yet to commence it’s wet season proper which usually in the 1st week of November. With La Niña in place, the potential for the country to receive more rain days are imminent therefore come November, the current scenario is expected to change.”

Please see the attached “Seasonal Climate Outlook (Nov-Jan 2021) ” from the PNG National Weather Service ( http://www.pngmet.gov.pg) for more information. Attached document: NWS_NDJ21.pdf.

For more general information about climate in our region, see: