Heavy rainfall to hit parts of Karnataka, yellow alert issued. The India Meteorological Department (IMD) issued a yellow alert for heavy rain accompanied by thunderstorms, lightning, and squalls in South Interior Karnataka, including Bengaluru, from October 21 to 24. IMD also predicted that the region will witness thunderstorms, lightning, and squalls on October 19 and October 20. Notably, rainfall in Karnataka has been below normal in October.