关键词: 逗点回波, “人”字形回波, 螺旋形回波, “逆风区”, 中气旋, 辐合区, 准噶尔盆地

Abstract: Radar echo evolvement characteristics of a hailstone and severe rainstorm process on July 25, 2008 were analyzed in the south edge of Junggar basin based on Doppler radar weather data and conventional observational data. The results indicate that this process occurs in convective instability stratification from Siberian to cold trough of the southeastern Balkhash Lake. There is mesoscale convergence shear line from low layer to ground. The evolvement of this severe rainstorm could be divided into three phases, i.e. comma echo, “人” shape echo and spiral echo, and they are corresponding with adverse wind area, mesoscale cyclone and convergence region in terms of radial velocity distribution. Radar echo intensity central value of hailstone exceeds 65 dBz. Echo tops (ETOP) of 60 dBz and 65 dBz are 5.5 km and 3 km, respectively. Vertically integrated liquid water content increases from 10 kg•m^-2 to 70 kg•m^-2. Radar echo intensity central value of severe rainstorm exceeds 60 dBz. ETOP of 55 dBz and 60 dBz are 3.7 km and 2.2 km, respectively. Vertically integrated liquid water content increases from 15 kg•m^-2 to 55 kg•m^-2. Doppler radar products are indicative of monitoring, forecasting and warning of hailstone and severe rainstorm.

Key words: Comma echo, ‘人' shape echo, Spiral echo, Adverse wind area, Mesoscale cyclone, Convergence region, Junggar basin