%0 Journal Article %A LU Huanzhen %A SUN Xiaolei %A LIU Yiwei %A SUN Jianyuan %T The Development Characteristics of Meso-scale Convective System During a Disperse Heavy Rainfall Process %D 2018 %R 10.11755/j.issn.1006-7639(2018)-04-0667 %J Journal of Arid Meteorology %P 667-675 %V 36 %N 4 %X

Based on conventional observation data, automatic weather station data, satellite data, Doppler radar data, wind profiling radar data and the Variational Doppler Radar Analysis System (VDRAS) data, the evolution characteristic of meso-scale convective system during a disperse heavy rain process in Tianjin in the night of August 6, 2016 was analyzed. The results were as follows:(1) The warm and moist air flow on the edge of subtropical high, weak shear, southeasterly jet stream and moist tongue in low level, weak convective inhibition, and the southward movement of the northern cold air provided favorable condition for the severe rainfall. (2) The developed and strengthened meso-β scale convective system in the southwest area of Bohai Sea moved northward, then merged with the meso-γ scale convective cells triggered in the front of the meso-β scale convective system and enhanced, leading to local heavy rainfall in the southeastern part of Tianjin. The local severe precipitation in the eastern part of Tianjin was caused by the southward movement of the meso-β scale convective system in the northeastern part of Hebei. In front of the convective system, new thunderstorms were triggered constantly and strengthened to a meso-β scale convective system with the shape of first line and then herringbone, which moved less first, and then moved southward with the convective cells moving into the northern region, resulting in heavy rainfall in the southern and northern parts of Tianjin. (3) The convergence line between southeast wind and northwest wind evolved from land and sea breeze convergence line, which was the convergence system, thus resulting in the development of the prophase convective system in the southwestern part of Bohai Sea. The convection over the northeast coast of Tianjin was caused by the convergence line, which was formed by the cold horizontal outflow (northeast wind) in the front of convective system in the northeastern part of Hebei and sea breeze (southeast wind). The herringbone convection system in the south-central region of Tianjin was caused by a mesoscale vortex and two convergence lines, which was formed by the cold horizontal outflow (northeast wind and southeast wind) in the front of convective system in the northeastern and southeastern Tianjin and environmental cold air (northwest wind). (4) Cold air moving southward started from the appearance of the northerly at a height of 3000-4000 m.

%U http://www.ghqx.org.cn/EN/10.11755/j.issn.1006-7639(2018)-04-0667