Abstract:
Based on MICAPS routine weather data, automatic weather station meteorological data and radar echo data, the radar echo characteristics of short-term heavy precipitation (≥ 30 mm/h) during heavy rainstorm in Xinjiang River Basin of Jiangxi Province are analyzed. The results indicate that: (1) There are five echo forms of short-term heavy precipitation in the Xinjiang River Basin, which are short echo band, flocculent echo cluster, squall line echo band, supercell on echo band, and isolated cell. (2) The squall line echo band and the supercell on the echo band exhibit typical strong convective echo characteristics, with echo intensity reaching 65 dBZ and Vertical Integrated Liquid Water (VIL) ranging from 55 to 60 kg/m
2, sometimes accompanied by strong weather such as hail, thunderstorms, and strong winds. The echo intensity of the other three echo forms ranges from 45 to 55 dBZ, and the VIL ranges from 5 to 20 kg/m
2, belonging to low centroid precipitation echoes. (3) When the strong precipitation echo intensity is ≥45 dBZ, strong echo area is 200~399 km
2, producing ≥5 mm/10 min rain intensity. When the echo intensity is ≥50 dBZ and the strong echo area is ≥500 km
2, it is easy to generate ≥10 mm/10 min rain intensity. (4) When short-term heavy rainfall occurs in the Xinjiang River Basin, there is a significant convergence of wind direction and speed at a height of 3 km, which promotes the formation and development of convective cells.