Prediction of lightning activity is important for different meteorological and physical applications. However, numerical weather prediction models don't take into account any electrical effects. Thus all forecasts of lightning events are based on indirect nonelectrical indexes, which are widespread in meteorology. But comparison of indexes and experimental data shows that the size of potentially dangerous region and time of extreme danger are usually poorly estimated. Modern mesoscale numerical models and sufficient computation capacity allows us to propose a new algorithm of lightning forecast based on direct calculations of electric potential and electric field in thunderclouds. This method is used for real thunderstorm simulations in Nizhny Novgorod region and shows good correlation with radar data. In the nearest future the use of the regional lightning location system is planned which will allow us to work on the development of a new nowcasting system in the Upper Volga region.