ISSN:
1436-5065
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
,
Physics
Notes:
Summary This study has been carried out in order to investigate the predictability of a rapidly developing storm over the Mediterranean area, by comparing the behaviour of three different meteorological models. The models chosen are the global, variable mesh, model ARPEGE, which is running operationally at Metéo-France, and two limited area models, namely ALADIN (also developed at Metéo-France) and BOLAM (developed in Italy, mainly at FISBAT). This comparison study has been performed by a cooperation among the French Meteorological Service and the National Research Council of Italy (CNR) FISBAT and IFA institutes. In this paper we present the results obtained by integrating the models on a short time-range, corresponding to the developing stage of a strong cyclone that moved rather quickly to the North from Northern Africa, associated with perturbed weather and distinct mesoscale features. In particular, this cyclone was characterized by a low-level warm core, associated with very strong winds and precipitation. All the three models were successful in describing the main characteristics of this cyclogenesis event, in particular the rapid evolution of the low level vortex. However, important differences emerged in “forecasting” the value of the pressure minimum, its position and time evolution, and the associated distribution of precipitation. When the large scales are treated by using analyzed rather than forecast lateral boundary conditions, the two LAMs perform better than the global model in simulating the low evolution but the global high resolution model better describes the general features of the cyclogenesis. Differences in model performance are found especially in the distribution of precipitation forecasts, suggesting two main conclusions: insufficient descriptions of mountains can change the location of the precipitation release, the precipitation scheme of the ALADIN model is sensitive to the lateral boundary conditions. The overestimation of the cyclone in BOLAM seems due to an oversensitivity to the latent heat release that intensifies the circulation in the cyclone core.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01030271
Permalink