Abstract: This work extends upon previous publication, Bachelor's thesis, which described unrelativistic motion of an electron in a storm cloud, which was represented by homogenous electric field, along with element of friction, Chandrasekhar function. In a short time, observed electron was accelerated to the relativistic speeds. In storm clouds, sometimes R-waves occur when  high-frequency electromagnetic wave passes through the plasma with magnetic field. These waves rotate right-handed along field lines, same as fast electron. Therefore, element describing interaction between electromagnetic R-wave and given electron was introduced into the motion equation, presented in this work.
Because this is clearly a relativistic problem, several attempts were made at creating special relativistic motion equation this year, all of them unsuccessful. Finding the element of friction, which is represented by Chandrasekhar function in classical physics, has proven to be very problematic, perhaps even impossible.