SINGAPORE – The La Nina weather pattern, which typically brings wetter weather to South-east Asia including Singapore, is expected to continue for the next few months. A United States government weather forecaster on Thursday (Aug 11) placed the odds of conditions continuing into November at 80 per cent.

La Nina is a periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific that typically causes warm ocean waters to pile up around East Asia and parts of Australia, triggering heavy rains.

The phenomenon can also increase the chances of more storms during the Atlantic hurricane season.

The US Climate Prediction Centre, in its latest monthly bulletin, said the chances for La Nina conditions will gradually decrease to 60 per cent during December to February next year.

During the past month, below-average sea surface temperatures expanded across the central and eastern equatorial Pacific Ocean and weekly indices indicated renewed cooling, reflecting continued La Nina conditions, the centre noted.

Rainfall remained suppressed over the western and central tropical Pacific and enhanced over Indonesia, it said.

La Nina conditions occur every three to five years and can run for successive years, according to the US National Weather Service. The latest La Nina began in 2020 and if it continues into early next year, it would be only the third time the phenomenon has happened three years in a row since 1950.

The Climate Prediction Centre said while a majority of computer prediction models suggest that La Nina will transition to neutral conditions in January-March 2023, forecasters were split on this outcome, resulting in equal forecast probabilities for that season.