Case Study of Convection Induced by Topography Over Southern Brazil Using The WRF Model

A case of formation of convective clouds over the center-western part of Santa Catarina State (located in Southern Brazil) during the morning-time was studied. During the night-time of 06 Jun 2007, a large area of low top cloudiness (cumulus and stratocumulus) covering Paraná and Santa Catarina States propagated eastward; embedded in this cloud system, over the center-western part of Santa Catarina State, the onset of convective clouds took place during the morning-time of 07 Jun 2007. Simulations using the WRF model with horizontal grid spacing of 10 km and 35 vertical levels show that the Serra do Mar mountain range acted as a barrier to the low-level northwesterly flow from Mato Grosso do Sul, leading to atmospheric convergence over the westernmost edge of the mountain range. The WRF model was able to represent the directional and vertical wind shear, the vertical velocity and the strong confluence of mass over the convective regions. The convection mechanism also was dependent on the generation of Low-Level Jet and/or Maximum Velocity Core at the lower levels of the atmosphere. The results expanded a previous published work of the same case based on simulations using the MM5 model.