India will likely have a normal monsoon, with a chance of ‘above normal’ rain in August and September, the India Meteorological Department (IMD).
The IMD’s confidence stems largely from global weather models pointing to negligible chances of El Nino, a warming of the central equatorial Pacific that’s associated with the drying up of monsoon rain.
It has also officially redefined the definition of what constitutes ‘normal’ rainfall and reduced it by 1 cm to 88 cm. The June-September rainfall accounts for 75% of the country’s annual rainfall.
The expectation of excess rain comes from a forecast by the dynamical model or the Monsoon Mission Coupled Forecast System — that relies on supercomputers, mathematically simulating the physics of the ocean and the atmosphere. According to this forecast, there is a “high probability (70%)” for the rainfall to be “above normal to excess”
The Indian Ocean Dipole, a temperature anomaly in the ocean that can increase monsoon rain, was also expected to be in a “neutral” state during the monsoon.