Application of time-lagged ensemble approach with auto-regressive processors to reduce uncertainties in peak discharge and timing

An accuracy evaluation using observations from 2002 to 2009 found that the time-lagged ensemble approach alone produced significant bias but the AR processor reduced the relative error percentage of the peak discharge from 60% to 10% and also decreased the peak timing error from more than 10 h to less than 3 h, on average. The proposed methodology is easy and inexpensive to implement with the existing products and models and thus can be immediately activated until a new product for forecasted meteorological ensembles is officially issued in Korea.