Precipitation Evolution in Tropical Cyclones After Landfall

根据美国天气研究计划，飓风预测的几个方面已被确定为高度优先的研究领域。更好地了解和预测飓风登陆后的降雨量是这些高度优先领域之一。这项研究的主要目的是了解登陆后飓风降雨量和降雨分布的控制机制。具体地说，首席调查员将研究总雨量、暴雨的面积覆盖范围、降雨相对于轨道的对称性，以及降雨类型(对流和非对流)。有无与飓风的槽相互作用和飓风的温带转换是登陆后降水演变的重要因素，这些相互作用将被包括在研究中。研究将采用两种主要方法：对大量飓风的总降雨量进行气候学研究，以确定可能的行为范围；以及极端事件的案例研究。将使用气候学研究的现有雨量计数据和个案研究的业务多普勒雷达数据(WSR-88D)来估计降雨量。国家闪电探测数据将被用来提供有关降水性质的更多信息。成功完成这项研究将有助于更好地了解热带气旋内的降水过程，最终将有助于更好地预测登陆后的洪水。

Under the U.S. Weather Research Program, several aspects of hurricane prediction have been identified as high priority areas of research. Better understanding and prediction of rainfall from hurricanes after they make landfall is one of these high priority areas. The major goal of this research is to understand the mechanisms that control the amount and distribution of rainfall in hurricanes after landfall. Specifically, the Principal Investigators will examine the total rain volume, the areal coverage of heavy rainfall, the symmetry of rainfall with respect to the track, and the type of rainfall (convective versus nonconvective). The presence or absence of trough interactions with the hurricane and extratropical transition of the hurricane are significant factors in the evolution of precipitation after landfall and these interactions will be included in the study.Two major methodological approaches will be employed: a climatological study of total rainfall in a large number of hurricanes in order to establish the range of possible behavior; and case studies of extreme events. Rainfall estimates will be made using existing raingauge data for the climatological study and operational Doppler radar data (WSR-88D) for the case studies. National Lightning Detection Data will be used to provide additional information about the nature of the precipitation.Successful completion of this research will lead to better understanding of precipitation processes within tropical cyclones, which eventually will result in better forecasts of post landfall flooding.