A Study of Formation for “Black Storm” Using GMS-4 Imagery

The casue of formation for the black storm over the part regions of Gansu and Ningxia Provinces during late afternoon and early night on 5 May 1993 are investigated using GMS-4 S-VISSR data every hour and conventional data. The results show that it was mainly caused by mesoscale convective system with a squall line in advance of a cold front. It moved eastward and basically consorted with 700~500 hPa mean flow. The predictability of this “black storm” is discussed.