Abstract

SILVA, Gustavo Leite da; SILVA, Alex Santos da  and  YAMASAKI, Yoshihiro. Validation of data assimilation in the inference of a radar reflectivity with the MM5 system. Rev. bras. meteorol. [online]. 2012, vol.27, n.1, pp. 75-84. ISSN 0102-7786.  http://dx.doi.org/10.1590/S0102-77862012000100008.

On certain occasions the Rio Grande do Sul State is affected by atypical weather systems events which are in the category of mesoscale phenomena. The inability of global forecast models to appropriately simulate several localized effects, which occurs over the most different regions, associated to the fast increase of computational resource, is facilitating and increasingly inducing the use of mesoscale models to improve the understanding of anomalous and severe events and also as a necessary and indispensable operational tool. In order to evaluate the skill of mesoscale model to provide precipitation forecasts, with space and time scales compatible with those of a Doppler meteorological radar, a mesoscale modeling system, the MM5, is implemented to explore the occurrence of the relatively severe precipitation event; occurred near the city of Canguçu / RS, on January 11, 2008. The event was arbitrarily selected; to evaluate the model skill in inferring the reflectivity of the meteorological radar, installed in Canguçu / RS, running the MM5 model with and without conventional data assimilations, as well as to get an approach of the thermo-hydrodynamics and synoptic conditions analysis.

Keywords : PCA; PSA; reflectivity; MM5 system.