2007年四川“4.14冰雹”个例分析

Case Analysis of “4.14 Hail” of Sichuan in 2007

摘要: 2007年4月14日21~23时，四川省成都、眉山、绵阳、宜宾等10市27县区出现了风雹类的强对流天气。本文阐述了此次冰雹天气的实况过程，利用常规地面和高空观测等资料，分析了此次强对流天气，其中包括冰雹形成的大尺度环流背景，中尺度角度下的水汽、不稳定、抬升以及垂直风切变条件。最后对成都单站探空进行了分析，成都上空出现低层暖湿、中层干冷的不稳定层结条件，同时具备强的上升气流，以及适宜的0℃层、−20℃层高度和深厚的垂直风切变的条件时，会出现强冰雹天气。希望从此次个例分析中总结经验，为今后四川地区冰雹的预报作参考。

Abstract: From 21 to 23 on April 14, 2007, the gale and hailstorm occurred in 10 cities and 27 counties of Sichuan Province, including Chengdu, Meishan, Mianyang and Yibin, etc. In this paper, the live broadcast of the hail weather is described. Besides, using the conventional surface and high alti-tude meteorological observation data, in combination with other data, the severe convective weather is analyzed, including the large scale circulation background in the formation of the hail, the conditions of moisture, instability, lift and vertical wind shear in formation of the hail from the meso-scale perspective. Finally, the analysis of radiosonde of Chengdu is studied, the results indicate that the strong hail weather will appear if the atmospheric environment could meet the following conditions: warm and wet low layer, cold and dry middle layer, strong rising air currents, suitable 0˚C, −20˚C layer height and strong vertical wind shear conditions. We hope that the experience of this case analysis will be the reference for the hail forecast in Sichuan area in the future.