El Nino to return and impact Vietnam this year

El Nino is the warm phase of the El Nino–Southern Oscillation (ENSO) and is largely associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific.

It is accompanied by high-air pressure in the western Pacific coupled with low air pressure in the eastern Pacific. Its phases are known to last close to four years.

Reality shows that El Nino impacts the global climate and causes disruption to normal weather patterns, which as a consequence can lead to intense storms in some places and droughts in others.

During the El Nino cycle, droughts and prolonged heat often occur in western Pacific countries, such as Vietnam, the Philippines, Malaysia, Indonesia, Thailand, Laos, and Australia. As a coastal country, Vietnam is located in the zone of monsoon systems and is strongly affected by changes occurring in atmospheric and oceanic conditions, including the El Nino phenomenon.

Studies conducted on the effects of global warming on rainfall and temperature worldwide indicate that El Nino leads to increased wet and dry spells, prolonged heat waves, and warmer winters, and Vietnam is no exception.

Strong heat waves hit the country between 1997 and 1998, as well as between 2014 and 2015 when El Nino returned, with daytime temperatures reaching a record high of 39.6℃ in the northern and southern regions, climbing to as high as 41.5℃ in the north-central region. 

After three years of the La Nina weather pattern which is the other phase of ENSO, meteorologists predicted that the El Nino phenomenon is likely to return in late May or early June, with a probability of up to 80%, and this phenomenon may last into early 2024. This year is predicted to be hotter compared to 2022, and the fifth or sixth hottest year on record.

The early days of May saw many localities nationwide experience their first strong heat waves of the year, with daytime temperatures rising sharply to nearly 40℃. Notably, 44.2℃ was recorded at the weather station in Nghe An province, marking an all-time high in the country.

Nguyen Van Huong, an official of the National Centre for Hydro-Meteorological Forecasting, says that heat waves this year will come early and tend to be much more intense compared to previous years.

“The heat is likely to increase its intensity from May to August, mainly in the Northern and Central regions. The number of hot days in 2023 may be more than in 2022. It is likely that the highest temperature values observed in previous years will be broken this year,” says the meteorologist.

The hot weather in the northern and central regions is predicted to last from May to August, with the hottest months falling in June and July. The average heat wave is anticipated to last between two and four days, or even longer.