The arc behavior in an arrangement of parallel arc rails with a splitter plate in between has been investigated experimentally and in numerical computations. Thereby, the arc is simulated by coupling finite-volume modeling for the gasdynamics and finite-elements modeling for the electromagnetics. The formation of arc roots on the splitter plate can be described by a thin layer of elements with a current-density dependent specific resistance. The simulations were extended to model the experimental arrangement exactly. Additionally, net emission coefficients and radiation heat conductivity of air plasma instead of a simplified T4 net emission of a black body were used to model the radiative cooling of the arc. The results of the arc voltage, the arc movement and the splitting process have been compared to measurements and high speed movies of the arc and yield good correlation. Moreover, the simulations allow good insight into the temperature distribution of the arc and the movement of the pressure
waves caused at the arc ignition.