<p>This paper presents the results of numerical modeling of the microphysical and electrical characteristics of convective clouds accompanied by thunderstorms in the northern regions of Russia in the summer of 2019. The study was conducted using a coupled model structure based on the Weather Research and Forecast model and an electrification module that takes into account non-inductive and inductive charge generation mechanisms. The modeling was conducted at high spatial resolution (2&#xa0;km) for four typical cases in the Republic of Karelia, Arkhangelsk and Vologda Oblasts, and the Komi Republic. Particular attention is paid to assessing the influence of the Hallett-Mossop secondary ice formation mechanism on the intensity of electrical processes in clouds. It is shown that taking the Hallett-Mossop mechanism into account leads to a statistically significant increase in the modeled electric field strength (by 30–60%) and the number of lightning strikes (by 20–49%) for all considered cases. The highest sensitivity to the Hallett-Mossop mechanism was found for cases with the most intense convection and high supercooled liquid content in clouds in the temperature range of -8 to -3&#xa0;°C. Validation results with lightning detection data confirmed the adequacy of the model, demonstrating good spatiotemporal agreement between the model electric field peaks and observed lightning discharges. It is concluded that taking the Hallett-Mossop mechanism into account in electrification schemes is critical for accurately forecasting thunderstorm activity in northern regions, where such phenomena are becoming increasingly relevant due to climate change. The obtained results have practical significance for improving forecasting systems for hazardous convective phenomena in Arctic and subarctic regions.</p>