Preliminary Study on Atmospheric Stratif ication Structure and Radar Characteristics of Hail Weather in Early Spring in Foshan

This study used MICAPS data, sounding data, radar data and NCEP2.5×2.5 reanalysis data to analyze the three hail events in Foshan in early spring (February to March) in the past two years. The results suggest: (1) The weather situation of the hails on 21 February 2019 and on 27 March 2020 were both the frontal low trough type, and the weather situation of the hail on 18 March 2020 was the elevated thunderstorm type. (2) The “cold upper and warm lower” stratif ication structures in the processes of the three hails were not obvious, which does not satisfy the rule that the larger the ΔT85, the larger the hail diameter, but the“dry upper and wet lower” stratif ication structure were obvious; the maximum thermal buoyancy intensity in the processes of the hails on 21 February 2019 and 27 March 2020 were over 6 ℃, which had the potential for large hail and satisfy the rule that the larger the H-/H+ (the ratio of the thickness of cold cloud to warm cloud), the larger the hail diameter. (3) The overhang echoes on the radar chart were obvious. V-shaped gaps and obvious medium cyclones were also detected in the processes of the hails on 21 February 2019 and 27 March 2020, and three-body scattering spikes were obviously detected at high elevation angles in the process of the hail on 27 March; the VIL value of the three processes of the hails were not big, which may be one of the differences between hail in early spring and hail in summer.