The end of the rain-giving Summer Monsoon is being awaited in India now thatSeptember is nearing the halfway mark.As of Monday, the India Meteorology Service (IMD) had not yet called an end tothe Monsoon in the northwestern India, where the Monsoon normally ends first.
The IMD have assessed seasonal rainfall, nationwide, at near normal (within 1percent weighted average) as of early September, with less than one month leftin the official Summer Monsoon remaining.
Distribution of rainfall within India, however, has varied substantially. Forexample, rain shortfalls in the populous northeastern states of West Bengal,Jharkhand, Bihar and Uttar Pradesh have raised concerns for agriculture andwater supply.
In contrast, stretches of southern, central and desert northwest India havebenefited from above-normal rainfall.
Map showing normal withdrawaldates for the India Summer Monsoon. Map credit: India MeteorologyDepartment.The vast weather system known as the Indian Summer Monsoon normally begins nearthe first of June in Sri Lanka and southern India, reaches its fullest extentover the Subcontinent in July, then begins its withdrawal towards the south andeast starting with Pakistan near the first of September.
By the middle of September, rains of a summer Monsoon have normally yielded todryness over much of northwestern India, especially in the state of Rajasthan.
The start of October marks the official end of the Summer Monsoon on theSubcontinent, although a fall Monsoon follows in southern India and Sri Lanka.
The IMD deem the Monsoon to have ended based upon a few objective criteriabased upon rainfall, pressure patterns and moisture content of the atmosphere.
For example, five continuous days of rain-free weather in a given are wouldsatisfy the first of these criteria.
Story by Jim Andrews, AccuWeather.com Senior Meteorologist
