The India Meteorological Department (IMD) has issued a warning for an above-normal monsoon season in Kerala, a state on India’s tropical Malabar Coast, which has nearly 600 km of Arabian Sea shoreline, with the state expected to receive heavy rainfall.
While the rest of the country is likely to experience normal rainfall, the southern peninsula will be affected by positive Indian Ocean Dipole (IOD) conditions, leading to enhanced precipitation in Kerala and its neighboring areas from mid-July.
The IMD Director, K. Santhosh has stated that the latest global model forecasts show high probabilities of positive IOD conditions, indicating that above-normal rainfall is likely in June for Kerala and the southern peninsula.
Positive IOD occurs when there is a warmer sea temperature over the western Indian Ocean compared to the eastern Indian Ocean, leading to increased sea surface temperature and higher evaporation, ultimately resulting in heavy rainfall along the western coast.
A significant positive IOD factor played a crucial role in the floods that affected Kerala in 2018 and 2019. During those years, there was above-average precipitation in June and July, followed by a large increase in rainfall in August.
Conversely, in 2019, the rains were deficient in June and July, but there was a substantial excess of precipitation in August. Although there was some impact, it was lower compared to the previous year due to reduced rainfall in June and July.
Currently, the forecast suggests an above-average rainfall in June with positive IOD conditions likely to contribute to increased rain over the next few months. The Kerala State Disaster Management Authority (KSDMA) is closely monitoring these developments. June and July are expected to experience heavy monsoon rains across the state, and KSDMA is observing whether the development of El Niño conditions will reduce rainfall in August, thus overshadowing the impact of the positive IOD.
A meeting of all department heads is scheduled to review monsoon preparedness on May 30, called by the state’s Chief Minister, according to KSDMA Member Secretary, Sekhar L. Kuriakose.