A European precipitation index for extreme rain-storm and flash flood early warning
A European precipitation index for extreme rain-storm and flash flood early warning
复制标题
DOI：
10.1002/met.1328
复制
发表时间：
2015-01-01
影响因子：
2.7
通讯作者：
Thielen, J.
中科院分区：
文献类型：
--
作者：
Alfieri, L.;Thielen, J.
极端暴雨在欧洲多个地区，特别是地中海沿岸沿着引发毁灭性的山洪暴发。尽管最近在天气预报方面取得了显著进展，但大多数极端暴雨和山洪暴发的预警系统仍然是基于雨量计和天气雷达的降雨量测量，而不是预测。因此，警报的提前时间被限制在几个小时之内，并且通常在事件已经发生时发出警报。这项工作提出了一种新的预警系统，在欧洲的强降水事件，旨在确定在短时间内的极端降雨量积累的预测和小规模的集水区容易山洪暴发。该系统以最近开发的基于模拟气候学的欧洲降水指数（EPIC）为基础，该指数是使用COSMO-LEPS集合天气预报计算的，随后在预报范围的每个时间步用伽马分布拟合。计算警报阈值的概率，并在检测到潜在极端事件时生成警报点。在欧洲，超过22个月的日常运行与观测到的暴雨事件和山洪暴发的比较表明，检测概率高达90%，对应于45个正确预测的事件，平均提前时间为32小时。版权所有（c）2012皇家气象学会
Extreme rain storms are known for triggering devastating flash floods in various regions of Europe and particularly along the Mediterranean coasts. Despite recent notable advances in weather forecasting, most operational early warning systems for extreme rainstorms and flash floods are still based on rainfall measurements from rain gauges and weather radars, rather than on forecasts. As a result, warning lead times are bounded to a few hours and warnings are usually issued when the event is already taking place. This work proposes a novel early warning system for heavy precipitation events in Europe, aimed at identifying forecasts of extreme rainfall accumulations over short durations and within small-size catchments prone to flash flooding. The system is based on the recently developed European Precipitation Index based on simulated Climatology (EPIC), which is calculated using COSMO-LEPS ensemble weather forecasts and subsequently fitted with gamma distributions at each time step of the forecast horizon. Probabilistic exceedence of warning thresholds is calculated and alert points are generated where potentially extreme events are detected. Comparison of daily runs over 22 months with observed rainstorm events and flash floods in Europe denotes a probability of detection up to 90%, corresponding to 45 events correctly predicted, with average lead time of 32 h. Copyright (c) 2012 Royal Meteorological Society