This work studied the ignition enhancement and ignition kernel development of H2/air mixtures in a nanosecond discharge between two cylindrical electrodes at atmospheric pressure and an initial temperature of 1000 K. A two-dimensional multi-scale adaptive reduced chemistry solver for plasma assisted combustion (MARCS-PAC) with detailed combustion chemistry and transport properties was developed and validated by incorporating the plasma solver PASSKEy and the unsteady reactive flow solver ASURF+. The results show that the streamer propagates between the two electrodes and creates chemically active excited species as well as radicals together with fast gas heating. The plasma-generated active species and gas heating significantly enhance low temperature ignition. In addition, the electrode separation distance also affects the ignition kernel development. This work provides an important tool to understand kinetic enhancement of non-equilibrium plasma ignition and optimize ignitor design.