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Peter Knippertz and Andreas H. Fink

-averaged anomaly of −23%. These results suggest difficulties of the ECMWF model in triggering convection in cases with an anomalous moisture inflow into the study region prior to day 0 but without a direct synoptic forcing by an upper-level trough as for the hits. The possible influence of a misforecasted synoptic setting is addressed in section 6c . The composite analysis for the false alarm cases reveals very large anomalies in Z500, MSLP, and TD2M ( Fig. 12g ). Note, however, that the strength of the

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Françoise Guichard, Nicole Asencio, Christophe Peugeot, Olivier Bock, Jean-Luc Redelsperger, Xuefeng Cui, Matthew Garvert, Benjamin Lamptey, Emiliano Orlandi, Julia Sander, Federico Fierli, Miguel Angel Gaertner, Sarah C. Jones, Jean-Philippe Lafore, Andrew Morse, Mathieu Nuret, Aaron Boone, Gianpaolo Balsamo, Patricia de Rosnay, Bertrand Decharme, Philip P. Harris, and J.-C. Bergès

models (LSMs) run in offline mode under a common atmospheric forcing based on observational products. (The data used are those from the ALMIP-Exp2 exercise.) The five LSMs that are currently used in the operational NWP and mesoscale models were selected from the whole ALMIP ensemble for subsequent analysis. A comparison of the 24-h mean evapotranspiration estimates provided by these five LSMs is shown in Fig. 7 . The LSMs are consistent with each other in terms of the synoptic structures discussed

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Adrian M. Tompkins and Laura Feudale

. 1997 ; Eltahir 1998 ), extratropical intrusions ( Roca et al. 2005 ), cloud and aerosol radiative forcing ( Tompkins et al. 2005a ), the African and tropical easterly jets ( Cook 1999 ; Thorncroft et al. 2003 ), and mesoscale organized phenomena such as squall lines and African easterly waves ( Albignat and Reed 1980 ; Diongue et al. 2002 ; Grist 2002 ; Fink and Reiner 2003 ; Mekonnen et al. 2006 ). Representing these interactions poses a particularly demanding challenge for dynamical

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Anna Agustí-Panareda, Anton Beljaars, Carla Cardinali, Iliana Genkova, and Chris Thorncroft

consequences for the prediction of African easterly wave (AEW) activity in the region on daily to medium-range time scales. First, since some AEWs clearly develop in this eastern region, it is possible that the current observing system fails to pick up AEWs in their early stages of development. Capturing them sooner in the analysis would likely have significant benefits for downstream prediction. Also, recent analyses of AEWs suggest that they are triggered by finite-amplitude diabatic forcing ( Berry and

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O. Bock and M. Nuret

are also extensively used for scientific research, either as large-scale forcings for mesoscale atmospheric simulations in case study experiments or as a full three-dimensional description of the atmospheric and surface parameters for climate research. In this latter case, reanalyses are of special interest since they are produced with a fixed version of an NWP model and the only changes in analysis and forecast performance result from changes in the observations that are assimilated. Within the

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