Analysis of a sandstorm weather case in April 17,2008 in the south of Junggar Basin

Using data of basic observation,automatic meteorological ground stations and numerical forecasting product T213,we analyzed the causes of a sandstorm weather process in April 17,2008 pm.in Shihezi city of Junggar Basin.This weather process was formed under the West Siberian Cold Trough moving towards southeast and developing greatly.The involvement of very cold air made the West Siberian Cold Trough developed further,which provided the forcing condition for sandstorm.The vertical structure of Siberian Cold Trough provided the mechanism of momentum transmitting downwards for sandstorm.High-altitude jet and High-altitude front zone concurred to produce Sandstorm in the medium and high-latitude regions.And there also was an exchange of Dynamic and Thermal Fields.The Strong sandstorm occurred under the conditions of the rear of cold front,the front of cold high pressure,changes in air pressure for 3h,the region of the greatest change in temperature and the airflow divergence.