Heavy rainfall and thunderstorm warning issued for several states, list released. The India Meteorological Department (IMD) has issued heavy rainfall and thunderstorm warning for several states/UTs for Monday and Tuesday (October 5 and 6). Heavy rainfall is very likely over Karnataka, Kerala, Tamil Nadu and Puducherry. Thunderstorm accompanied with lightning and gusty winds of around 40-50 kmph is likely over Kerala, Puducherry, Lakshadweep, Tamil Nadu and Himachal Pradesh.