华北产生雷暴大风的动力热力综合指标分析及应用

Analysis and application of thermo-dynamical and dynamical indexes associated with thunderstorm gale in North China

应用MICAPS重要天气报告数据,筛选出2005—2010年夏季华北地区26次典型雷暴大风过程。选取K指数、对流有效位能、大气可降水量、大风指数、中低层垂直速度、垂直螺旋度、垂直能量螺旋度等7个动力或热力指标,利用NCEP 1°×1°再分析资料计算和统计了槽前型和西北气流型雷暴大风发生时的指标阈值。基于统计结果,进一步设计了指标叠套技术,将其应用于2011年6月华北地区两次不同类型雷暴大风的潜势预报中。结果表明,雷暴大风实际发生区域与指标叠套区域一致性较好,验证了该方法对华北雷暴大风预报的有效性。

Using the important weather data of MICAPS, 26 typical thunderstorm gale cases which took place in North China in the summer from 2005 to 2010 are chosen. With NCEP reanalysis data and 7 averaged statistical dynamical and thermo-dynamical indexes （K index, CAPE, precipitable water vapor, wind index, mean vertical velocity between 850-97：5, hPa, vertical helicity and vertical energy helieity index）, the index threshold are calculated when trough frontage thunderstorm gale and northwestern current thunderstorm gale happened. Based on the results, overlapping sets of indices are designed and applied to forecast two different kinds of thunderstorm gale which took place in June of 2011. The results show that the areas where thunderstorm gales happened are identical with the forecasted areas, and the method has a ca-pability to forecast thunderstorm gale in North China.