Lavers David A, Pappenberger Florian, Zsoter Ervin
European Centre for Medium-Range Weather Forecasts, Shinfield Park, Reading RG2 9AX, UK.
1] European Centre for Medium-Range Weather Forecasts, Shinfield Park, Reading RG2 9AX, UK [2] School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK.
Nat Commun. 2014 Nov 11;5:5382. doi: 10.1038/ncomms6382.
Widespread flooding occurred across northwest Europe during the winter of 2013/14, resulting in large socioeconomic damages. In the historical record, extreme hydrological events have been connected with intense water vapour transport. Here we show that water vapour transport has higher medium-range predictability compared with precipitation in the winter 2013/14 forecasts from the European Centre for Medium-Range Weather Forecasts. Applying the concept of potential predictability, the transport is found to extend the forecast horizon by 3 days in some European regions. Our results suggest that the breakdown in precipitation predictability is due to uncertainty in the horizontal mass convergence location, an essential mechanism for precipitation generation. Furthermore, the predictability increases with larger spatial averages. Given the strong association between precipitation and water vapour transport, especially for extreme events, we conclude that the higher transport predictability could be used as a model diagnostic to increase preparedness for extreme hydrological events.
2013/14年冬季，欧洲西北部发生了大面积洪水，造成了巨大的社会经济损失。在历史记录中，极端水文事件与强烈的水汽输送有关。在此我们表明，与欧洲中期天气预报中心对2013/14年冬季的降水预报相比，水汽输送具有更高的中期可预报性。应用潜在可预报性的概念，发现在欧洲一些地区，水汽输送可将预报时效延长3天。我们的结果表明，降水可预报性的降低是由于水平质量辐合位置的不确定性，这是降水形成的一个关键机制。此外，可预报性随着空间平均值的增大而增加。鉴于降水与水汽输送之间存在很强的关联，特别是对于极端事件，我们得出结论，更高的水汽输送可预报性可作为一种模式诊断方法，以提高对极端水文事件的应对准备。
