| 摘要: |
| 本文利用观探测资料、NCEP/NCAR再分析资料、雷达资料等，对2018年3月4日广西、湖南、江西一次区域性雷暴大风、冰雹、飑线等强对流天气进行分析，结果表明：高低空急流耦合，700hPa暖中心，850hPa强暖湿低空急流+暖脊+切变线，地面暖低压倒槽+辐合线+冷锋，上述系统是此次强对流天气的触发者和组织者；极端温差及水汽分布形成异常热力不稳定和位势不稳定；中低层强垂直风切变形成的动力不稳定使飑线组织化发展且长时间维持；弓形飑线与中低层风向夹角大，在西南急流引导下，飑线以60～120km·h-1速度向东北加速移动。在强低层风切变下，冷池能够触发其前沿空气产生较强上升运动，有利于飑线发展和维持。大风发生前10～30min，中层存在大风速核明显下降现象。 |
| 关键词: 雷暴大风；垂直风切变；雷达回波；冷池 |
| DOI： |
| 投稿时间：2021-11-02修订日期：2022-04-12 |
| 基金项目: |
|
| Circulation Conditions and Environmental Parameters of a Severe Convective Weather |
| wangzichen,wanghongjun |
| (Xi’an Satellite Control Cente) |
| Abstract: |
| Based on surface and radiosonde observation, NCEP/NCAR reanalysis data and weather radar data, a severe convective weather event with thunderstorm, hail and squall line on March 4, 2018 in Guangxi, Hunan and Jiangxi province was analyzed. The results show that the coupling of high-level jet and low-level jet streams caused strong convergence and upward movement between Guangxi and Jiangxi. The 700hPa warm center + shear line, 850hPa warm ridge + shear line, and ground warm low level inverted trough + convergence line + cold front triggered and organized the severe convective weather event. Extreme temperature difference and water vapor distribution form abnormal thermodynamic instability and potential instability. The dynamic instability caused by strong vertical wind shear in the middle and lower layers plays an important role in the organized development of squall lines. The bow-shaped squall lines have a large inclined angle with the wind direction and move northeast, steered by low-level jet stream with a steady speed of 60-120km/h. With strong low-level wind shear，the cold pool can trigger the front air to produce strong upward movement, which is favorable for forming a new squall line. 10-30 minutes before the occurrence of surface strong wind, the height of strong wind in the middle layer decreased significantly. |
| Key words: Thunderstorm gale； Wind shear； Radar echo；Cool pool |
