A two-dimensional compressible nonhydrostatic numerical model is proposed for the simulation of thermal bar in a deep freshwater lake. An equation of state is used which shows a nonlinear dependence of density on temperature and pressure. Numerical experiments demonstrate the peculiarities of the temperature distribution and lake currents associated with the thermal bar. The two-cell convection divides the nearshore region into three zones in the direction of the temperature front movement: warm, transition, and cold regions. The temperatures of the transition zone are close to those of maximum density. Downward currents are developed between two cells in the transition zone. Their calculated values are rather large (max w = 0(0.1)-0(1) cm/s). This indicates the intensive exchange between nearsurface and deep waters.