Abstract:Based on conventional observation data, satellite data, automatic weather station data and NCEP(1°×1°) reanalysis data, the physical mechanisms and mesoscale features of severe convective weather processes in Anhui Province in recent ten years （2001-2010） are analyzed. The results show that: The development of severe convective weather is related to the large scale circulation background, which needs abundant water vapor, unstable stratification, the trigger mechanism or strong lifting, and the strong development of strong storms often have inversion layer, strong vertical wind shear, mid level dry air and other favorable conditions. However, the importance of these conditions in different large scale circulation backgrounds is not the same, and these conditions also produce different types of severe convective weather. The convective instability of cold vortex pattern and behind trough shows that: the lapse rate of temperature in low levels is large; vertical wind shear is strong; the wind strongly clockwise with height increasing; westerly jet exists in 400-500 hPa, which is closely related with the severe weather area; and there exist obvious mesoscale low pressure, convergence line, and dry line. This pattern mainly causes thunderstorm, strong wind and hail. The CAPE is usually large in ahead of trough pattern, low level jet exists, the horizontal and vertical shears of wind are large; the short wave trough moving to east rapidly is the main trigger mechanism of strong convective weather; and the low level moisture condition is good. This pattern mainly causes thunderstorm, strong wind, flood and tornado. Through statistics of the various weather elements and physical parameters of severe convective weather under different types of large scale circulation background, and extraction of eliminating empty forecast indicators using environment field, we will significantly improve the tornado identification ability and early warning level based on the reflectivity factor and the average radial velocity of Doppler radar. This paper compares the physical mechanism and mesoscale characteristic differences between two severe convective weather processes which caused squall line, vast thunderstorm wind and hail on Huang Huai and Jiang Huai Regions one of which occurred in the situation of subtropical high edge and ahead of trough during 19-20 July 2010, the other occurred in the situation of Northeast cold vortex on 3, 5, and 14 June 2009. This work may improve short time forecasting ability of severe convective weather under different types of large scale circulation background.