冀东地区“9.27”雷暴大风的雷达回波特征

为提高唐山地区雷暴大风的预报和监测能力,利用常规气象资料、秦皇岛站多普勒雷达资料和每6 h 1次的NCEP FNL 1°×1°再分析资料，分析了2012年9月27日（简称“9.27”）在冀东出现的大范围雷暴大风天气过程。结果表明：近乎垂直的西来槽和上干下湿的结构是此次天气产生的环境背景，地面冷锋和干线触发了此次天气过程。低层辐合、高层辐散以及充足的水汽条件使系统进一步加强，强大的倾斜上升气流使系统得到维持。雷达回波图上可识别出明显的穹窿结构、阵风锋、前侧入流和后侧出流回波特征和大风区，垂直速度剖面存在明显的辐合区。根据雷达回波特征演变推断，这次雷暴大风主要由强回波高度的快速下降，强冷空气入侵和回波的快速移动产生。

Radar Echo Characteristics of a Thunderstorm Gale in East Hebei Province

The paper aims to improve the forecasting and monitoring of thunderstorm gale in Tangshan. Using the conventional data, Qinhuangdao station Doppler radar data and 1 × 1 lattice point NCEP material, the weather process of a thunderstorm gale in east Hebei Province on Sep 27, 2012 (shortly named as“9.27”) was analyzed. The results showed that: this gale occurred in a background of nearly vertical west trough with the stratification of upper dry and lower wet, the trigger of this weather process was ground cold front and the trunk. The low-level convergence, high-level divergence and adequate moisture further strengthened the system, the strong updraft enabled the system to be maintained. The radar echo clearly showed an obvious dome structure, the gust front, the lateral inflow, the back flow and the gale zone. According to velocity profile, there was an obvious radial convergence zone. On the basis of the radar echo evolution, this thunderstorm gale was produced by the rapid decrease of strong echo height, the strong cold air invasion and the squall line of fast moving.