The India Meteorological Department (IMD) has announced a likely delay in the onset of monsoon over Kerala this year, with the predicted arrival date now set for June 4, four days later than the normal date of June 1. The IMD, which has been issuing operational forecasts for the monsoon onset over Kerala since 2005, utilizes a state-of-the-art statistical model to make these predictions, with a model error of +- 4 days. According to the IMD, the monsoon over Kerala occurred last year on May 29, aligning closely with their prediction of May 27. In fact, the operational forecasts for the monsoon onset over Kerala have been accurate in the past 18 years, with the exception of 2015.
The IMD’s statistical model takes into account six predictors of monsoon onset, including minimum temperatures over Northwest India, pre-monsoon rainfall peak over the south Peninsula, outgoing longwave radiation (OLR) over the South China Sea, lower tropospheric zonal wind over the Southeast Indian Ocean, mean sea level pressure over the subtropical NW Pacific Ocean, and upper tropospheric zonal wind over the North East Indian Ocean. The southwest monsoon, which signifies the transition from a hot and dry season to a rainy season over the Indian mainland, is characterized by its onset over Kerala. This delay in the monsoon’s arrival could have implications for agriculture, water resources, and overall weather patterns in the region.
In other weather-related news, the IMD has stated that while no heatwave conditions are expected in Delhi, temperatures are anticipated to remain high, reaching up to 40 degrees Celsius over the next seven days. The relative relief from severe heatwave conditions in May can be attributed to Western disturbances affecting parts of northwest India. As the next western disturbance approaches, heatwave conditions are not expected for the coming week, although temperatures will remain elevated.