A numerical mesoscale model (COAMPS) is used to study the evolution of kinematic and thermodynamic structure of the Alabama sea and bay breeze circulations in weak shear environments. Five cases from Medlin and Croft (1998) were investigated. The general and expect features of sea and bay breeze circulations are captured by the model simulations, including horizontal and vertical wind shifts, thermal contrast between land and water surface, vertical stability over water and land, return currents and moisture increase. These are then visualized as a means of test guidance. The relationship of the circulations to synoptic flow and local physiographic features also investigated and revealed in the visualization. The very first convective cells to produce radar return above 30dBz are confirmed to have a location preference according to the flow regime and local conditions. This result can assist the forecasters in understanding the insight of convective cell structure, and improve the short-term forecast accuracy of the location of thunderstorm initiation based on the routine observations.