和田地区2019年4月24~28日沙尘天气过程分析

Analysis of Sand and Dust Weather Process Is Hotan Area from April 24 to 28, 2019

摘要: 2019年4月26日夜间和田地区自西向东出现了沙尘暴天气过程。利用常规天气资料、和ECMWF、ECMWF细网格和T639数值预报产品，对此次天气过程的影响系统、有关物理量场等方面进行分析，得出以下结论：1) 前期南疆盆地气温持续升高，热低压发展强烈，为沙尘暴天气较好的热力条件；2) 此次风沙天气过程主要是由于欧洲脊东南衰退，西西伯利亚低槽东移南压影响下形成的。此次环流形势特点：欧洲脊前北风带加强，西西伯利亚低槽南压，低槽分裂短波东移而引起的；3) 这次天气过程是一部分冷空气从南疆西北翻山入侵南疆盆地，有一部分冷空气从东面灌入盆地而引起了沙尘天气；4) 中低层冷暖空气的作用下，容易引起不稳定能量释放，因此冷暖空气在本地区交汇，低层辐合高层辐散的强上升运动区有良好的对应是导致这次沙尘暴天气的发生重要原因之一；5) ECMWF数值预报产品和ECMWF细网格数值预报产品，500 hPa影响系统西西伯利亚低槽的预报位置准确，但较实况槽的移动速度快点。EC细对此次天气预报与实况基本吻合，10米风场有重要指示意义；6) 通过对数值预报的成功运用和分析，这次沙尘天气预报服务非常成功、准确、及时、超前，社会效益十分显著。通过服务注意到，对做好数值预报解释应用工作，提高预报时效和准确率，值得进一步研究。

Abstract: On the night of April 26, 2019, a sandstorm weather process occurred in Hotan area from west to East. Based on the conventional weather data, ECMWF, ECMWF fine grid and T639 numerical forecast products, the influence system of the weather process and relevant physical quantity fields are analyzed, and the following conclusions are drawn: 1) the temperature in the southern Xinjiang basin continued to rise in the early stage, and the thermal low pressure developed strongly, which is a good thermal condition for the sandstorm weather; 2) this sandstorm weather process was mainly formed by the southeast recession of the European ridge and the eastward movement and southward pressure of the West Siberian trough. The characteristics of this circulation situation are as follows: the strengthening of the north wind belt in front of the European ridge, the southward pressure of the West Siberian trough, the splitting of the trough and the eastward shift of the short wave; 3) in this weather process, some cold air invaded the basin of Southern Xinjiang from the northwest of Southern Xinjiang, and some cold air poured into the basin from the East, causing sand and dust weather; 4) under the action of the cold and warm air in the middle and low levels, it is easy to cause the release of unstable energy. Therefore, the intersection of the cold and warm air in the local area and the good correspondence between the strong upward movement areas of the convergence of the low levels and the divergence of the high levels are one of the important reasons for the occurrence of this sandstorm; 5) ECMWF numerical prediction products and ECMWF fine grid numerical prediction products, the predicted position of the West Siberian trough of the 500 hPa impact system is accurate, but the moving speed is faster than that of the actual trough. EC fine is basically consistent with the actual weather forecast, and the 10 m wind field has important indicative significance; 6) through the successful application and analysis of the numerical forecast, the sand and dust weather forecast service is very successful, accurate, timely and advanced, and the social benefits are very significant. Through the service, it is noted that it is worth further research to do a good job in the interpretation and application of numerical prediction and improve the timeliness and accuracy of prediction.