A tornado lasting for more than 15 minutes hit the Yangtze River near Jianli, Hubei province, on Monday night when a ship carrying 456 people capsized, the national weather authority said on Tuesday.
The wind speed of the 1-kilometer-wide tornado reached Level 12 on the Beaufort scale (117 km/hor above), and lasted for 15 to 20minutes, according to a statement released by the China Meteorological Administration.
Between 9 pm and 10 pm, rainfall in the area exceeded 64 millimeters, the administration said.
Tornadoes are rare in Hubei province, but have been recorded there, Zhang Zuqiang, head of the Disaster Relief Bureau and spokesman for the CMA, said on Monday afternoon.
They are common in central areas of the United States, but China has fewer such occurrences, Zhang said, adding that hot, humid weather in late spring and summer can lead to tornadoes.
However, it is difficult to forecast when and where they will occur, said Xue Jianjun, senior engineer with the national weather authority.
Meanwhile, many provinces in southern China had excessive rainfall in May, the administration said.
The average rainfall in southern China reached 328 millimeters from May 5 to May 31-56.6 percent more than in the same period last year - while northern China has experienced hot and dry weather.
These conditions are because of the increasingly strong El Nino phenomenon, the administration said.
The ENSO, an index measuring the El Nino, rose to 1.3 degrees in May, the highest data since the onset of El Nino, it said, adding it has affected China and many countries.
The warming of the surface of the tropical eastern Pacific Ocean is expected to continue, reaching moderate levels in summer and causing more extreme weather, the administration said.
Provinces in southern China need to prepare for more torrents and floods, while provinces in the southwest and northwest will need to fight drought conditions this summer, it added.