Ensemble‐based targeting experiments during FASTEX: The effect of dropsonde data from the lear jet

Abstract

AbstractIn this study we evaluate the performance of the Ensemble Transform (ET) technique, which is one of several targeting methods used in real time during the Fronts and Atlantic Storm‐Track EXperiment (FASTEX). ‘Targeted’ observations were taken adaptively in those upstream areas identified in real time as most relevant for improving the initial conditions for forecasts of synoptic‐scale storms developing downstream. the upstream areas were identified as regions where the effect of extra observations at a future analysis time could produce the largest decrease in the largest likely forecast error at a preselected later verification time at a given downstream location. the ET technique s..