Séminaire
Different from ‘normal’ torrential rain events, persistent severerainfall (PSR) is a highly disruptive and damaging weather phenomenonthat usually refers to severe impacts over larger areas and longerdurations. The abnormally stable development of the associatedlarge-scale circulation, and accurate small-scale forecast haveimportant effects on PSR forecasts in high-resolution regional model.The newly developed forecasting methods, in which the spectral nudging(SN), lateral boundary filtering (LBF) and update initial conditions(UIC) are incorporated into a new methodology (SN+UIC+LBF), wereemployed, in the regional Weather Research and Forecasting (WRF)model, to investigate the potential for improving the predictioncapability for the rainy season in China, via using as much merits ofthe global model having better predictability as to the large-scalecirculation and of the regional model as to the small-scalefeatures. The new methodology was found to besuccessful in improving the prediction of the atmosphericcirculation and precipitation. Furthermore, the larger the magnitudeand the longer the lead time, the more obvious the improvement interms of the accumulated rainfall of PSR events
Juliette.Mignot@locean-ipsl.upmc.fr