Simultaneous Ensemble Post-Processing for Multiple Lead Times with Standardized Anomalies

Abstract

eparate statistical models are typically fit for each forecasting lead time to post-process numerical weather prediction (NWP) ensemble forecasts. Using standardized anomalies of both NWP values and observations eliminates most of the lead-time specific characteristics so that several lead times can be forecast simultaneously. Standardized anomalies are formed by subtracting a climatological mean and dividing by the climatological standard deviation. Simultaneously post-processing forecasts between +12 and +120 h increases forecast coherence between lead times, yields a temporal resolution as high as the observation interval e.g., up to ten minutes, and speeds up computation times while achieving a forecast skill comparable to the conventional method.