Lightning hazard due to overvoltages resulting from flashes differing in polarity and strokes

The paper deals with a calculation of risk, which may appear within a structure due to lightning discharges. An attempt to involve into the calculations not only lightning flashes but also their strokes has been undertaken. A discrepancy between the results achieved for flashes and for strokes has been assessed and discussed. On the basis of such considerations practical conclusions have been formulated.