A transmission line model which incoporates general discharge velocities is presented, and formulas for the current and charge densities are derived. The resultant formulas for the electromagnetic fields are given in a from applicable to intercloud and intracloud discharges. A spectral study of a vertical discharge results in a velocity equation. This equations relates the velocity of ionization of the discharge to the current at the base of the discharge and the radiation field of the sferic. Analysis of a dimensionless parameter for a Bruce-Golde type discharge and an example suggest that vertical discharges may become horizontal after entering the cloud.