Multiple updates report that thundershowers are likely to bring relief from prolonged heat in northern districts of Tamil Nadu. The forecast indicates that light to moderate rainfall may occur, with thunderstorms expected, particularly during evening hours. Chennai is also included in the expected weather impact, with similar chances of thundershowers during the evening period. The reports frame the showers as a factor that could help ease the ongoing heat conditions in the region rather than as widespread, continuous rain. No additional details on storm intensity, duration beyond the evening window, or broader regional coverage are provided in the supplied excerpts. Overall, the information is consistent across sources: thunderstorms and associated rainfall are forecast to occur, and they are expected to offer temporary relief from high temperatures in northern parts of the state, including the Chennai area.