Joint Calculation of Vertical Velocity and Convective Indices in the WRF Model for the Analysis and Forecasting of Tornado-risk Situations

Calculation of convective indices using the WRF model for the analysis and forecasting of tornado-risk situations involved the calculation of vertical velocity field. The results of calculations for four tornados registered in 2015 are presented. It is shown that if the values of the indices are above the thresholds, the localized intensive convective cell is formed in the model in the vicinity of the maximum values of the indices and at the moment when these values are reached. The possibility of using this result as an additional predictor of tornado occurrence is discussed. It confirms the conclusion on the possibility of prediction of tornado-risk situations with the lead time to three days and with the accuracy to several hours in time and to 200 km in space.