Study on sandstorm in the western section of Hexi Corridor of 2020

A diagnostic analysis of the dust storm weather occurring in the western part of the Hexi Corridor from 27-30 June 2020 was carried out using Jiuquan city’s live data, as well as ECMWF numerical forecasts, and the NCEP reanalysis information was used to draw a theta dust storm model based on the routing principle. The results show that: 1.In the early stage of sandstorm, there was no precipitation in Suzhou and Jinta counties in March and April, which resulted in dry surface and thickened soil layer. These factors created favorable conditions for the occurrence of dust weather. 2.Development of unstable trough eastward in front of the ridge of Mountain Ural at 500 hPa, The cold high pressure is continuously strengthened in the process of moving, which is the large-scale system leading to the sandstorm. Thermal depression in front of ground cold front is the main cause for the outbreak of the severe sandstorm. 3.The beginning and ending time of the sandstorm can be accurately predicted by the simulation chart of sandstorm forecast, which has a good indication significance for the sandstorm forecast in the Hexi area.