The Characteristics of the Circulation Causing Continuous High Temperature and Drought in the Yangtze and Huaihe River Valley in 1994
The large-scale high temperature and drought weather occured in the Yangtze and Huaihe river valley,especially in the south of Jiangsu and Anhui province in 1994. It was concluded that its duration is only shorter than that in 1934, but longer than that in 1978. The following abnormal circulation situation was the main cause giving rise to such high temperature and drought weather. The Western Pacific sub-tropical high jumped to the region to the north of 27°N earlier to control the lower reaches of the Yangtze river in July. The typhoon moved westward more southerly and northward over the coastal water so that the continental high was steady in August. Meanwhile,another cause was that the westerly jet jumped northward quickly and maintained over the area from 42. 5°N to 47. 5°N after ending of the mei-yu period,therefore cool air moved more northerly.