| 摘要: |
| 【目的】为做好上饶市特大暴雨的预报预警工作。【方法】使用地面气象数据、MICAPS常规天气图、雷达拼图、强回波识别产品等资料，采用天气学、雷达气象学原理与分析方法，对2021年6月27-28日上饶市特大暴雨过程进行分析。【结果】(1)27日上饶市出现强降水天气，最大雨强达88.3mm·h⁻¹，累积雨量4h达218.7mm，24h达308.7mm。(2)500 hPa前倾槽、低层切变线、高空出流区、副高边缘辐合区叠加，水汽充足，湿层深厚，大气层结极不稳定。(3)≥45dBz强回波面积超过1000km²，回波覆盖区域出现多站≥30mm·h⁻¹短时强降水，当强回波面积超过2000km²时，出现≥50mm·h⁻¹短时强降水。(4)强降水回波组合反射率中心强度55~60dBz、回波顶高达14~17km、垂直积分液态水含量达15~17kg·m⁻²。反射率因子垂直剖面RCS强回波呈"直上直下"结构，伸展高度6.5km以下；径向速度垂直剖面VCS伴有速度对或下正上负的中层辐合结构。(5)差分反射率（ZDR）值在1.0~3.0dB之间，最大可达3.8dB；差分传播相移率（KDP）值的范围为0.75~2.0°·km⁻¹，最大达到3.0°·km⁻¹左右；差分传播相移（PDP）值大小位于40~70°之间；低层辐合、切变线的存在和高层辐散风场，对强降水的维持和发展十分有利。【结论】研究结果为上饶市特大暴雨的预警预报提供参考依据。 |
| 关键词: 特大暴雨;短时强降水;强回波面积;回波特征 |
| DOI： |
| 投稿时间：2024-03-10修订日期：2024-07-31 |
| 基金项目:国家重点研发计划课题(2022YFC3003904); 国家自然科学基金项目(41975001); 景德镇市科技计划项目(2022SF003); 江西省气象局面上项目(JX2022M03)。 |
|
| Analysis of Strong Echo Characteristics of an Extremely Heavy Rainstorm in Shangrao City |
| LU Qiufang,CHEN Baofa,LIU Yishu,WANG Xuan |
| (Shangrao Meteorological Office of Jiangxi Province，Kezhou Meteorological Office of Xinjiang Uygur Autonomous Region;Jingdezhen Meteorological Office of Jiangxi Province;Yingtan Meteorological Office of Jiangxi Province) |
| Abstract: |
| In order to do a good job in the prediction and early warning of extremely heavy rainstorm in Shangrao, the surface meteorological data, MICAPS conventional synoptic chart, radar mosaic, strong echo recognition products and other data are used to analyze the process of extremely heavy rainstorm that occurred in Shangrao from June 27 to 28, 2021 by means of the principles and analysis methods of synoptics and radar meteorology. The results show that:(1) On the 27th, Shangrao City experienced severe rainfall, with a maximum rainfall intensity of 88.3 mm·h⁻¹, accumulated rainfall of 218.7 mm in 4 hours, and 308.7 mm in 24 hours.(2) The 500 hPa forward dipping trough, low-level shear line, high-altitude outflow zone, and convergence zone at the edge of the subtropical high were superimposed together, resulting in abundant water vapor, deep wet layer,and extremely unstable atmospheric stratification.(3) The strong echo area≥45 dBz exceeded 1 000 km², and in the echo coverage area multiple stations experienced short-time severe rainfall of≥ 30 mm·h⁻¹ . When the strong echo area exceeded 2 000 km², short-time extreme heavy rainfall of≥ 50 mm·h⁻¹ occurred.intensity of composite reflectivity(CR) of heavy precipitation echoes was 55-60 dBz, the echo top height(ET)reached 14-17 km, and the vertical integrated liquid water content(VIL) reached 15-17 kg·m⁻². The strong echo of the reflectivity cross section(RCS) exhibited a"straight up and straight down" structure extending to a height less than 6.5 km. The radial velocity cross section(VCS) was accompanied by velocity pairs or a mid-level convergence structure of"bottom positive and top negative".(5) The differential reflectivity ZDR value ranged from 1.0 to 3.0 dB, with a maximum of 3.8 dB. The range of differential propagation phase shift rate 0.75-2.0°·km⁻¹ with a maximum of around 3.0°· km⁻¹ . The differential propagation phase shift P
DP value ranged from 40 to 70°. The existence of low-level convergence and shear lines, combined with the high-level divergent wind fields, were very beneficial for the maintenance and development of severe precipitation. These findings could be a reference for the early warning and forecasting of extremely heavy rainstorm in Shangrao City. |
| Key words: extremely heavy rainstorm; short time severe rainfall; strong echo area; echo characteristics |
