Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 12, 2449-2462, 2012
https://doi.org/10.5194/nhess-12-2449-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
03 Aug 2012
Verification of ensemble forecasts of Mediterranean high-impact weather events against satellite observations
J.-P. Chaboureau1, O. Nuissier2, and C. Claud3 1Laboratoire d'Aérologie, Université of Toulouse, CNRS, UMR5560, Toulouse, France
2GAME/CNRM, CNRS/INSU Groupe d'étude de l'atmosphère météorologique (GAME), URA1357, Toulouse, France
3Laboratoire de Météorologie Dynamique/IPSL, CNRS, UMR8539, Ecole Polytechnique, Palaiseau, France
Abstract. Ensemble forecasts at kilometre scale of two severe storms over the Mediterranean region are verified against satellite observations. In complement to assessing the forecasts against ground-based measurements, brightness temperature (BT) images are computed from forecast fields and directly compared to BTs observed from satellite. The so-called model-to-satellite approach is very effective in identifying systematic errors in the prediction of cloud cover for BTs in the infrared window and in verifying the forecasted convective activity with BTs in the microwave range. This approach is combined with the calculation of meteorological scores for an objective evaluation of ensemble forecasts. The application of the approach is shown in the context of two Mediterranean case studies, a tropical-like storm and a heavy precipitating event. Assessment of cloud cover and convective activity using satellite observations in the infrared (10.8 μm) and microwave regions (183–191 GHz) provides results consistent with other traditional methods using rainfall measurements. In addition, for the tropical-like storm, differences among forecasts occur much earlier in terms of cloud cover and deep convective activity than they do in terms of deepening and track. Further, the underdispersion of the ensemble forecasts of the two high-impact weather events is easily identified with satellite diagnostics. This suggests that such an approach could be a useful method for verifying ensemble forecasts, particularly in data-sparse regions.

Citation: Chaboureau, J.-P., Nuissier, O., and Claud, C.: Verification of ensemble forecasts of Mediterranean high-impact weather events against satellite observations, Nat. Hazards Earth Syst. Sci., 12, 2449-2462, https://doi.org/10.5194/nhess-12-2449-2012, 2012.
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