A new parameterization of the lightning-produced NO<sub>x</sub> has been developed for cloud-resolving models. This parameterization is based on three unique characteristics. First, the cells that can produce lightning are identified using a vertical velocity threshold. Second, the flash rate in each cell is estimated from the non-precipitation and precipitation ice mass flux product. Third, the source location is filamentary instead of volumetric as in previous parameterizations. <br><br> This parameterization has been tested on the 10 July 1996 Stratospheric-Tropospheric Experiment: Radiation, Aerosols and Ozone (STERAO) storm. Comparisons of the simulated flash rate and NO mixing ratio with observations at different locations and stages of the storm show a good agreement. An individual flash produces on average 121±41 moles of NO (7.3±2.5×10<sup>25</sup> molecules NO) for the simulated high cloud base, high shear storm. Sensitivity tests have been performed to study the impact of the flash rate, the cloud-to-ground flash ratio, the flash length, the spatial distribution of the NO molecules, and the production rate per flash on the NO concentration and distribution. Results show a strong impact from the flash rate, the spatial placement of the lightning-NO<sub>x</sub> source and the number of moles produced per flash.