Jiangsu province a frequent victim of tornadoes

Northern Jiangsu province is one of the regions in China most frequently hit by tornadoes, which present a challenge for the country to monitor and forecast, the national weather forecaster said on Friday.

The comment came after a tornado on Thursday hit Yancheng in coastal Jiangsu province, killing at least 98 people and injuring more than 800.

However, tornadoes caused by convective storms are not rare in China. The latest statistics showed that 43 tornadoes happened every year on average from 1991 to 2014, with 92 percent of them from April to August, according to the National Meteorological Center.

"Jiangsu province in the east and Guangdong in the south are the most frequently hit by tornadoes, with an annual average of 5.5 and 4.8 tornadoes in the two provinces, but most happen in scarcely populated areas," according to the center.

A tornado struck three villages in Shantou, Guangdong, on April 24, leaving seven people injured and more than 540 houses damaged.

The tornado in Jiangsu was caused by the confluence of hot and cold airflows as well as the rain, Zhang Tao, chief forecast officer with the center, told China Central Television.

"From early to midsummer, a band of rain moves from south to north across the country, while hot and humid airflow from the southwest is transporting plenty of moisture and heat to the area, and the cold air from the north is still active. The three collide in northern Jiangsu and form strong convective weather conditions, bringing gales, hailstorms and rainstorms," he said.

The center said that only the United States and Canada, where tornadoes are common, can issue tornado warnings a couple of minutes ahead of one striking. It explained that the small size and short duration of tornadoes contribute to the difficulty of forecasting them.

"A tornado is usually less than 100 meters wide, which is tiny compared to, for example, a typhoon, which is hundreds of kilometers in width. Moreover, a tornado lasts only around 10 minutes," the center wrote on Sina Weibo.

The most secure places to hide when a tornado occurs are underground spaces, and it is suggested that people take cover in low-lying ground and in ditches and stay away from trees, poles and billboards to avoid electric shock or being crushed.