雷暴大风与龙卷的预报预警和灾害现场调查

Forecasting Techniques and Damage Survey of Convectively Driven High Winds and Tornadoes

近年来强雷暴大风与龙卷导致的灾害事件引发广泛关注。在总结雷暴大风和龙卷机理、短期预报技术和天气形势特征基础上,给出了这两类天气的监测和短时临近预报预警技术,最后简要总结了灾后现场调查工作和风灾强度评估方法。雷暴大风多数是由对流风暴内强烈下沉气流产生;而龙卷一类由中气旋产生,另一类由辐合线上的中小尺度涡旋和快速发展对流风暴中的强上升气流共同作用形成。但归根结底,巨大的静力不稳定能量是产生强雷暴大风与龙卷(热带气旋龙卷除外)的必要条件。新一代天气雷达观测是雷暴大风与龙卷的监测和临近预警主要手段。自动气象站观测风场能够相当程度上监测大风天气,地球静止气象卫星和自动气象站变压、变温等观测资料也能够辅助监测雷暴大风天气,但龙卷监测尚无法直接使用这两类资料。对这两类天气所致灾害的现场调查工作依然必不可少。快速更新或者集合的高时空分辨率数值模式预报及其后处理是这两类天气短时预报的主要途径。

In recent years, the disasters, which were caused by convectively driven high winds and tornadoes, attracted more attention in China. This paper frstly summarizes the mechanisms, short-range forecasting techniques and synoptic situations of convectively driven high winds and tornadoes, then presents techniques of monitoring and warning on them, finally gives brief summary of damage survey and wind estimation methodology for them. Most of convectively driven high winds are caused by strong rear downdrafts of convective storms. However, one type of tornadoes was generated from mesocyclones, another type of tornadoes was caused by the combining effect of mesovortices and strong updrafts of convective storms in convergence line. Massive convective available potential energy is one of the necessary conditions favorable for convectively driven high winds and tornadoes （except for tropical cyclone tornadoes）. Monitoring and warning convectively driven high winds and tornadoes depend on the observations by new generation weather radar network. Observational winds from automatic weather station （AWS） can monitor convectively driven high winds to a great extent, and observations from geostationary meteorological satellites and pressure tendency and temperature tendency from AWS are also useful to monitor convectively driven high winds, but these data cannot directly be used to monitor tornadoes. Damage survey for the disasters caused by these two types of weather is still necessary. Short-term forecasting these two types of weather depends mainly upon a rapid update high-resolution （ensemble） numerical model and post-processing.