Abstract:

The singularly continuous overcast and rainy process occurred in Hubei province in late winter of 2009 which persisted 13 to 19 days.Through the realtime monitoring data compared with the same period in history and the monitoring by the index of continuous overcast and rainy extreme climate event，and combined with the impact and disaster information and related industry standards，the climate characteristics，extent，causes and effects of this process are preliminarily analysed.The results are as follows：（1）The characteristics of this continuous overcast and rainy process are early occurrence，long duration，heavy rainfall，low temperature，less sunlight and followed by some disaster such as thunderstorm，hail，freezing rain，glaze ice.This process in central and southern Jianghan plain and eastern Hubei province all achieve the standards of extreme climate events；（2）The continuous rainfall process is mainly caused by the singular change and adjustment of atmospheric circulation in East Asia；（3）The continuous rainfall has serious impact on agriculture，resident，traffic，business and also induces geological disasters in parts area，and impacts after disaster has appeared on the occurrence and development of crop disease.〖