Increased frequency of extreme weather due to lag effect of El Nino, expert says

The lag effect of the El Nino phenomenon has resulted in an increased frequency of extreme weather events, a meteorological expert said at a news conference.

"The National Climate Center's monitoring data reveals that the warm sea surface temperature in the central and eastern equatorial Pacific has been steadily decreasing since April, indicating that the El Nino phenomenon has entered a sustained phase of decline," said Jia Xiaolong, deputy director of the center.

Jia said the ocean's influence on climate demonstrates a delayed effect. Historical statistics indicate that during the spring and summer after the El Nino phenomenon weakens, the subtropical high-pressure system in the western Pacific Ocean remains consistently strong, facilitating the moisture transport toward the eastern areas of China. This, coupled with cold air activities, is expected to lead to increased precipitation levels in the eastern regions of China.

"As of Sunday, the national average temperature in April was 13.2 C, which was 1.9 C higher than the usual temperature for the same period in a typical year, marking the highest temperature for this period since 1961," he said.

"During this period, the national average precipitation stands at 61.1 millimeters, representing a 51.8 percent increase compared to the typical amount for the same period in a regular year. This figure signifies the second-highest level recorded for this period in history."

In April, China experienced eight regional heavy rainfall events, a notable increase from the typical three events during the same period in a standard year. In addition, the heavy rainfall in South China led to successive instances of two floods in the Beijiang River within the Pearl River Basin, Jia said.

Nine severe convective weather processes hit China, bringing disastrous effects to areas in Central China's Hunan province, Southeast China's Fujian province, South China's Guangdong province and Guangxi Zhuang autonomous region, and Southwest China's Guizhou and Sichuan provinces, he said.

It is expected that areas such as Hunan, Jiangxi, Fujian, Guangdong, Guangxi, Zhejiang, Jiangsu and Shanghai will experience a notable increase in precipitation in May, Jia said, who also warned of a potential risk of floods in these areas.

According to Jia, the persistent impact of the stronger-than-normal subtropical high-pressure system will result in increased rainfall across many regions of China this summer, from June through August, raising the risk of floods and waterlogging disasters.

While the rainfall in late April notably relieved the drought conditions in Southwest China, this year has seen a more severe drought condition in the area, with an average of 31.9 drought days, exceeding the usual amount by 13.8 days, Jia said.

He added that areas in central and eastern part of Yunnan province, the southern part of Sichuan province, Hainan province and the western part of Shandong province are facing moderate to severe drought conditions, with certain areas in the southeastern part of Yunnan experiencing extreme drought conditions.

It is expected that in most parts of Yunnan province, the eastern part of Guizhou province, the southern part of Sichuan province and Hainan province, there will be relatively less precipitation and higher temperatures in May, and the drought conditions will continue to worsen in these areas, he added.

He also cautioned about agricultural drought and forest fires in these affected areas.

In addition, as of Sunday, there were six dust and sand events in North China in April, an increase from the typical 4.1 events for the same period, and there is a high risk of dust and sand weather in the central and western parts of Inner Mongolia autonomous region, and Northwest China in May, according to Jia.